CARDIAC ABLATION: TYPES AND OUTCOMES

CARDIOVERSION AND ABLATION

JASSIN M. JOURIA

Dr. Jassin M. Jouria is a practicing Emergency Medicine physician, professor of academic medicine, and medical author. He graduated from Ross University School of Medicine and has completed his clinical clerkship training in various teaching hospitals throughout New York, including King’s County Hospital Center and Brookdale Medical Center, among others. Dr. Jouria has passed all USMLE medical board exams, and has served as a test prep tutor and instructor for Kaplan. He has developed several medical courses and curricula for a variety of educational institutions. Dr. Jouria has also served on multiple levels in the academic field including faculty member and Department Chair. Dr. Jouria continues to serve as a Subject Matter Expert for several continuing education organizations covering multiple basic medical sciences. He has also developed several continuing medical education courses covering various topics in clinical medicine. Recently, Dr. Jouria has been contracted by the University of Miami/Jackson Memorial Hospital’s Department of Surgery to develop an e-module training series for trauma patient management. Dr. Jouria is currently authoring an academic textbook on Human Anatomy & Physiology.

ABSTRACT

Atrial are serious disorders that can cause an irregular and/or rapid heartbeat, which can lead to serious clinical sequelae. Atrial is an example of an atrial that can lead to blood clots, stroke, or failure. Electrical and ablation are two procedures that can minimize these risks and treat atrial arrhythmia. Each of these treatments have risks and neither offers a complete success rate, but they can be very effective in providing greater quality of life, and extending the life expectancy of patients.

1 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Policy Statement

This activity has been planned and implemented in accordance with the policies of NurseCe4Less.com and the continuing nursing education requirements of the American Nurses Credentialing Center's Commission on Accreditation for registered nurses. It is the policy of NurseCe4Less.com to ensure objectivity, transparency, and best practice in clinical education for all continuing nursing education (CNE) activities.

Continuing Education Credit Designation

This educational activity is credited for 2.5 hours. Nurses may only claim credit commensurate with the credit awarded for completion of this course activity. Pharmacology content is 0.5 hours (30 minutes).

Statement of Learning Need

Cardioversion and cardiac ablation for the treatment of resistant atrial arrhythmia has been analyzed in the medical literature, including benefits and risks. Clinicians need to understand the indications and efficacy of both procedures to treat atrial arrhythmia and to reduce cardiac system burden. Clinical research is growing with evolving recommendations for clinicians managing refractory atrial arrhythmia and to plan cardioversion or ablation.

Course Purpose

To provide clinicians with knowledge of cardiac atrial arrhythmias and of the treatments of cardioversion and cardiac to reverse symptoms of atrial arrhythmia and potentially adverse outcomes.

2 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Target Audience

Advanced Practice Registered Nurses and Registered Nurses (Interdisciplinary Health Team Members, including Vocational Nurses and Medical Assistants may obtain a Certificate of Completion)

Course Author & Planning Team Conflict of Interest Disclosures

Jassin M. Jouria, MD, William S. Cook, PhD, Douglas Lawrence, MA, Susan DePasquale, MSN, FPMHNP-BC – all have no disclosures

Acknowledgement of Commercial Support

There is no commercial support for this course.

Please take time to complete a self-assessment of knowledge, on page 4, sample questions before reading the article. Opportunity to complete a self-assessment of knowledge learned will be provided at the end of the course.

3 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 1. Cardiac ablation generally involves inserting a catheter into the body and threading it through the

a. to the heart. b. to the lungs. c. to the left or right carotid . d. up to the .

2. The tip of the catheter has an electrode that sends radiofrequency energy through the tip of the catheter

a. to stimulate the heart. b. to remove scarring that may be causing arrhythmia. c. to break up blood clots. d. to damage the offending tissue.

3. Prior to an ablation procedure, a clinician may schedule a patient for a transesophageal echocardiogram (TEE) to

a. determine if catheterization is possible. b. locate a potential blood clot. c. identify scar tissue within the heart. d. locate the source of an arrhythmia.

4. A patient preparing for a cardiac ablation will typically take an anticoagulant, such as ______, because the risk of thrombus can be high.

a. warfarin b. clopidogrel c. propofol d. remifentanil

5. Most patients require enough anesthetic to produce ______throughout the cardiac ablation procedure.

a. general b. mild sedation c. conscious sedation d. anxiolysis

4 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Introduction

Cardiac ablation is a treatment option that has been shown to reduce or eliminate cardiac arrhythmias in many cases. Ablation is used for the treatment of tachyarrhythmias, including or , as well as some of the other supraventricular . The process of ablation alters the heart muscle by removing or destroying specific heart tissue with the goal of preventing the continuation of the arrhythmia. Catheter ablation may be performed by inserting a catheter using an epicardial or endocardial method, or a combination of the two. Catheter ablation types may also be specific to the type of arrhythmia such as with pulmonary antrum (PVA) isolation ablation and atrioventricular (AV) node ablation.

Overview Of Cardiac Ablation

The term ablation is defined as a process of removing or eliminating abnormal tissue that is causing harm. When cardiac ablation is performed, part of the heart muscle tissue is removed or damaged in a method that will affect how the heart beats. Under normal circumstances, myocardial tissue damage might only lead to further health anomalies but when a cardiac arrhythmia is present, the tissue destruction can change the electrical patterns of the heart enough that it returns to a normal rate and rhythm.

Overall, cardiac ablation is a mildly invasive procedure that usually involves a rapid recovery period and few adverse effects. Ablation involves inserting a catheter into the body and threading it through the circulatory system to the heart. The most common site of insertion is the femoral vein in the groin, although other areas are also considered, including the subclavian or internal jugular . The tip of the catheter has an electrode that targets the

5 nursece4less.com nursece4less.com nursece4less.com nursece4less.com affected node or area within the heart that is causing the arrhythmia. Catheter ablation procedures may use radiofrequency energy to damage the tissue; in some cases, is performed, which uses cold temperatures to damage the tissue through freezing. has been in use longer than cryoablation, and although the two techniques use different methods to destroy tissue, they are both still successful in eliminating areas that cause arrhythmias.48-50,55

Ablation Using Radiofrequency Energy

With radiofrequency energy, an electrode sends radiofrequency energy through the tip of the catheter to damage the offending heart tissue, heating it to enough intensity that it causes a burn to produce tissue scarring.16 The average amount of energy applied generally ranges from 20 to 50 watts. The clinician controls when to start and stop the procedure and the rate at which energy is delivered. The catheter can be moved and adjusted slightly within the heart’s structure to destroy the tissue in more than one area that is causing problems. Once the tissue has been scarred, the abnormal cells have been destroyed and electrical signals have been interrupted; the heart is able to function normally again.70,71

Cryoablation

With cryoablation, tissue is destroyed using cold instead of heat. A cryoballoon is attached to the end of the catheter. Cryoablation works through liquid nitrogen or argon gas that is compressed and transported through the tip of the catheter.79 The temperature of the gas is extremely cold, so that it freezes and destroys the tissue on contact.

Cryoablation is beneficial because the clinician is able to damage some of the tissue in the heart first without permanently scarring it. In this method, the

6 nursece4less.com nursece4less.com nursece4less.com nursece4less.com electrophysiologist can determine if the identified location is the area causing the arrhythmia. For example, after inserting the catheter, the cryoballoon is positioned near the point where the arrhythmia is supposedly being generated. The clinician applies the cold gas or nitrogen to the tissue to temporarily disable the cells and can determine if this is the precise location that needs to be destroyed. If it is not the correct location, the tissue can be allowed to rewarm after the cold application. If it is indeed the area that needs to be destroyed, the clinician can permanently scar the tissue by freezing it.50

A past review by Earley, et al., in the journal Heart investigated the use of cryoballoon ablation therapy for the treatment of AF. The results showed that not only did cryoablation specifically target the arrhythmogenic tissue, the process also served to debulk the left . This reduced the amount of tissue within the atrium, thereby eliminating more potential substrates that would contribute to arrhythmia generation.80 While radiofrequency ablation appears to pinpoint tissues more precisely, cryoablation is often able to reach larger areas at once while still maintaining a controlled environment.

Some patients can successfully treat AF with cryoablation but may also have just as positive outcomes with standard radiofrequency ablation. The destruction of tissue, regardless of the exact method in which it is delivered, is the strategic element in eliminating the origin of arrhythmias.

Pre-Procedure Precautions and Planning

As with cardioversion, the patient will first undergo an electrocardiogram (ECG) so that the clinician can determine the abnormal and rhythm and use the results as a baseline of comparison after the procedure

7 nursece4less.com nursece4less.com nursece4less.com nursece4less.com is complete. Other tests, such as laboratory testing for serum chemistry may be completed prior to the ablation. In particular, a clinician should look for electrolyte abnormalities that would manifest in a serum chemistry panel, including alterations in sodium and potassium values. Cardiac levels may also be tested.34,35

Laboratory tests should help to determine if a patient is at an increased risk for heart arrhythmia and/or failure. The patient may need supplemental oxygen, depending on whether the patient’s arrhythmia has affected the respiratory status. Sedation is provided as part of catheter ablation, and supplemental oxygen may be needed because of the effects of the or anesthetics used.46

A patient typically requires anticoagulation for several weeks before and after the ablation procedure, as risk of thrombus can be high. This is accomplished by prescribing an anticoagulant such as warfarin. A patient who takes warfarin is often required to stop the dose 1 to 2 days before the procedure.

Prior to an ablation procedure, a clinician may schedule a patient for a transesophageal echocardiogram (TEE) to locate a blood clot if one is present in the heart or surrounding tissue. A TEE is an ultrasound procedure that is used to look at the patient’s heart. A probe is inserted and guided down a patient’s throat to look at the heart. The ablation procedure may be postponed if the TEE finds evidence of a blood clot.32

Many patients, particularly those with arrhythmias that are causing frequent symptoms, take antiarrhythmic medications as part of their treatment routine for rate and rhythm control. These may include or

8 nursece4less.com nursece4less.com nursece4less.com nursece4less.com , which are drugs that may be stopped for a short period before the procedure. An individual may resume an antiarrhythmic medication after the procedure, or a health clinician may change the prescription to decrease the medication amount based on the success of the ablation.

An electrophysiologist is a type of specialist that performs catheter ablation. The actual procedure often takes place in the catheterization lab or an suite. The patient will have an IV in place for fluids and for administration of sedatives or analgesic medications. The IV line is also important to deal with side effects that may be caused by the ablation procedure. Side effects are rare; however, side effects encountered during the procedure may include hemodynamic compromise and instability that requires IV administration of medication, such as a vasopressor drug, and fluids.46,71,

An anesthesiologist is present to monitor the patient throughout the procedure and to administer and anesthetic agents, as well as analgesia, if needed. According to Deng, et al., in the Texas Heart Institute Journal, an anesthesia clinician is typically required during catheter ablation to monitor the patient throughout the procedure. This anesthesia clinician most often delivers perioperative care through monitored anesthesia care (MAC) or general anesthesia. Most patients require enough anesthetic to produce conscious sedation and will receive MAC throughout the process; in these cases, patients are sleepy during the procedure but can still follow commands. Although general anesthesia is uncommon for this procedure, there are some people with significant enough heart disease or those with prolonged, complex arrhythmias that would tolerate the procedure better with more anesthesia. When the goal is conscious sedation for the patient, drugs such as midazolam or remifentanil may be administered.70

9 nursece4less.com nursece4less.com nursece4less.com nursece4less.com During a cardiac ablation procedure, the electrophysiologist may attempt to induce the arrhythmia if the patient is not already exhibiting the abnormal cardiac rhythm. This can help the clinician locate the origin of the arrhythmia. Induction of an abnormal rhythm may be performed by administering intravenous epinephrine or isoproterenol.70 Most people undergo the procedure in a state of , even if they struggle with frequent episodes of arrhythmia. A comparison between the pre-op ECG and the patient’s rate and rhythm during the procedure is done to distinguish changes in the conduction cycle.81

Types Of Cardiac Ablation

There are several different types of cardiac ablation procedures that may be performed to treat arrhythmia. The type of procedure chosen is based on a number of factors, such as the type of arrhythmia, duration of the arrhythmia condition, whether harmful symptoms exist, and, the patient’s overall health. The potential risks associated with ablation must also be taken into account on a case-by-case basis for each patient.

Ablation procedures typically include forms of catheter ablation, in which the actual process is carried out by catheter insertion that induces damage in a particular area of the heart. Surgical ablation is another option in which a surgeon creates scar tissue at problematic locations on the heart through a surgical procedure. Catheter ablation is typically considered to be the procedure of choice for many because it is less invasive.

Catheter Ablation

Catheter ablation may be performed as epicardial, endocardial, or a combination of the two. Catheter ablation types may also be specific to the

10 nursece4less.com nursece4less.com nursece4less.com nursece4less.com type of arrhythmia, such as with pulmonary vein antrum (PVA) isolation ablation and atrioventricular node ablation.

Epicardial Ablation

With epicardial ablation, the area of ablation occurs next to the (sac surrounding the heart). This is necessary when the source of the arrhythmia does not come from inside the heart, which may be seen in cases of ventricular with concurrent . The are placed through the skin under the rib cage in the chest wall and threaded toward the heart for the ablation.69

Endocardial Ablation

Endocardial ablation is used to treat an arrhythmia that is generated from inside the heart. Endocardial ablation is more commonly performed when compared to the epicardial process and is typically considered to be the standard method. Endocardial ablation describes the process of accessing the circulatory system by inserting a catheter into a large vein or artery and threading the catheter to a location within the heart. Depending on the type of ablation procedure, the location of where the tissue scarring will take place varies.40,55

Choice of Procedure

As stated above, a health clinician decides what type of ablation to perform based on the patient’s health condition and the location of where the arrhythmia is generated. However, the type of ablation is also dependent on the training and capabilities of the healthcare facility performing the procedure. For instance, some locations do not have physicians trained in epicardial ablation and these services will need to be pursued elsewhere.

11 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Although the overall goal of ablation is to cause scarring of tissue that will stop the arrhythmia, factors such as the type of heart rhythm being treated and the location of the arrhythmia’s pacemaker can also impact the decision about the most appropriate type of ablation to perform.44

Subcategories of Catheter Ablation

There are also various types of procedures that are subcategories of catheter ablation. Catheter ablation may be performed to target specific areas of the heart for certain arrhythmias. Such examples include pulmonary vein isolation or AV node ablation.52,53,80

Pulmonary Vein Antrum Isolation Ablation

Pulmonary vein antrum isolation ablation is one of the more common techniques used in the treatment of paroxysmal atrial fibrillation. When this particular arrhythmia develops, it is possible that the origin of the electrical conduction impulse can come from a site other than within the atria, including from within the pulmonary vein. The pulmonary veins are connected to the left atrium and they play an important role of bringing oxygenated blood back to the heart after it is circulated to the lungs. Studies have shown that there is tissue within the pulmonary veins that can act as a pacemaker; consequently, it is possible that generation of electrical impulses for the heart’s conduction system can come from the pulmonary vein and can subsequently cause atrial fibrillation.

An article by Mahida, et al., published in the journal Arrhythmia & Electrophysiology Review discussed the factors related to the physiology of the pulmonary veins that may be more likely to lead to arrhythmias, including atrial fibrillation, in some people.22 The article stated that intravascular ultrasound examinations of the pulmonary veins among

12 nursece4less.com nursece4less.com nursece4less.com nursece4less.com persons with atrial fibrillation typically show veins with thicker tissue overall. Another study discussed in the review affirmed that the pulmonary veins of people studied to have AF have larger diameters overall in comparison to those without an arrhythmia. The abnormal increase in tissue and diameter of the pulmonary veins in these cases is thought to contribute to arrhythmia development and could be connected with increased instances of ectopy and irregular contractions. Further, histological studies of pulmonary vein tissue have shown that there are certain antigens present within the tissue that have pacemaker qualities and could generate electrical conduction signals.22 Because of these and other findings on the effects of the pulmonary vessels on the cardiac conduction system, catheter ablation that reaches the pulmonary veins can be successful in preventing abnormal generation of cardiac impulses leading to consistent arrhythmias.

Pulmonary vein ablation is a type of catheter ablation, which requires insertion of catheters into the groin in the femoral vein, where they are then threaded to the heart.22 Once the tip of the catheter reaches the right location, it locates the area of the pulmonary vein where the abnormal pacing is occurring. A catheter is inserted into the coronary sinus that will record and monitor the electrical activity in the left atrium. Because the electrode tip reaches the right atrium when first inserted, to get to the pulmonary vein, the catheter must be further threaded through to reach the left atrium. This is done by making two small puncture holes in the septum between the right and left atria through a process of transseptal puncture.

Transseptal puncture involves making a small hole between the right and left atria and inserting a catheter through. The medical clinician uses a sheath- covered needle to puncture the septum and positions a guidewire. Once the left atrium has been punctured, the needle is removed but the sheath

13 nursece4less.com nursece4less.com nursece4less.com nursece4less.com remains in place for the catheter to be passed through. The medical clinician actually makes two small puncture wounds and two total catheters are inserted into the left atrium. One of the catheters injects contrast into the area so the clinician can monitor the ablation process through . The second catheter is used for ablation and areas of the atrium and the pulmonary veins are first marked to measure anatomical position. Several areas around the pulmonary veins are scarred using tip ablation.71

Following ablation, a mapping catheter is placed into each of the pulmonary veins to measure electrical activity. The electrical activity is measured through an electrogram, which identifies areas where abnormal electrical activity is still occurring. The clinician can monitor the electrogram results and determine if there are other areas within the heart that will need further ablation before the catheters are removed.71

Mapping is often performed during PVA, as it allows the clinician to better understand the location of the arrhythmogenic tissue. There are times when the clinician may attempt to induce the arrhythmia during the procedure to be able to see if there are other areas generating arrhythmias. A study by Bunch, et al., in the Journal of Thoracic Disease showed that patients who had recurrent AF following ablation ended up having arrhythmogenic tissue at several sites that were not treated during their initial procedures.72 Consequently, clinicians began to isolate all pulmonary vessels during subsequent procedures to reduce the risk of later arrhythmia recurrence. Of note, this process may have long-term consequences that have yet to be identified.72 Ongoing research and the outcomes of PVA when total pulmonary vein isolation is achieved will determine whether procedural techniques may need to evolve.

14 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Atrioventricular Node Ablation

When a patient is evaluated with an arrhythmia that originates from the atrioventricular (AV) node, AV node ablation may be an appropriate option for treatment. AV node ablation has been shown to be successful in the treatment of atrial fibrillation. It is most commonly used to treat cases of paroxysmal or persistent AF among patients who have otherwise not responded to antiarrhythmic therapy. It has a low risk of complications and a higher rate of success when compared to some other types of procedures.

Patients who undergo AV ablation most commonly have the procedure done to treat AF.21,22 When the tissue at the level of the AV node is destroyed, the atria are no longer able to send abnormal electrical impulses to the ventricles so that the ventricles can contract normally. However, the atria may continue to fibrillate, creating an ongoing, increased risk of thrombosis.

This type of ablation involves inserting a catheter in the femoral vein in the groin and threading it to the heart. Once inside the heart, it is placed near the AV node between the atria and the ventricles and radiofrequency energy is applied to damage the node and cause scarring. In this way, the AV node will no longer generate an impulse for the cardiac electrical signal and the arrhythmia should be resolved.

Cardiac ablation used to treat atrial flutter can improve patients’ clinical outcomes overall. A review by Dewland, et al., in the journal PLOS One evaluated the clinical outcomes and the impact on use of healthcare resources among patients who underwent catheter ablation for the treatment of atrial flutter.17 According to the review, risk of acute stroke was not significantly reduced after subjects underwent ablation. Alternatively, catheter ablation did significantly reduce the risk of later development of

15 nursece4less.com nursece4less.com nursece4less.com nursece4less.com atrial fibrillation. Ablation for atrial flutter was also associated with lower risk of inpatient hospitalization, decreased visits to the emergency department, and decreased healthcare utilization costs overall.17 Based on these outcomes, catheter ablation remains a valid and successful form of treatment for atrial flutter, resulting in decreased risks to patients overall, as well as a decreased risk of the condition recurring.

A review published in the Annals of Translational Medicine evaluated various forms of catheter ablation for treatment of longstanding persistent AF in comparison to other forms of the arrhythmia. The review revealed various studies where patients underwent procedures in which ablation was performed with simultaneous modification of some nerves. For example, one procedure involved pulmonary vein ablation, which is a common procedure performed for treatment of AF but there were some cases in which patients simultaneously had vagal nerve innervation. By impacting the autonomic nervous system, the researchers in the studies believed they could have better success with treatment of longstanding AF. However, the studies in the review still showed lower rates of success at follow up (between 1 to 5 years) for preventing recurrence of longstanding AF when compared to successfully treating paroxysmal AF.55

Atrioventricular Node Ablation and Pacemaker Insertion

Atrioventricular node ablation must be accompanied by insertion of a permanent pacemaker to regulate the heart’s rate and rhythm because the ablation process may cause the heart rate to slow so much that the individual develops bradycardia.44 The insertion of a pacemaker will ensure that the patient maintains a normal heart rate that is fast enough to support normal circulation. The type of pacemaker used with AV node ablation may vary slightly based on availability and the patient’s presenting arrhythmia.

16 nursece4less.com nursece4less.com nursece4less.com nursece4less.com The pacemaker may be placed several weeks before the ablation is performed. The pacemaker is positioned in the upper chest in a pocket of tissue under the skin with the wires leading directly to the heart. The wires needed to connect the pacemaker to the heart can be put into place while the clinician is still performing ablation and has access to the intracardiac structures. When it is performed with AV node ablation, it can be done all at the same time.

Typically, a pacemaker that is implanted in the chest requires lead wires that run from the device to the heart. The pacemaker sends impulses through the wires directly to the heart when the heart rate drops too low, thus stimulating the heart to beat faster and correcting the bradyarrhythmia. In some cases, a wireless pacemaker may also be used and has been shown to be successful for some people, eliminating the need for wires from the pacemaker.43,44 One case series presented in the journal Heart Rhythm Case Reports discussed two patients who underwent AV node ablation for the treatment of atrial flutter and who had wireless pacemakers implanted during their procedures. Both of the patients received Micra pacemakers, which were inserted directly into the heart, rather than a pocket created in the upper portion of the chest. Because the device is placed in the heart, there is no need for wires.43

Overall, the Micra pacemaker is very small in comparison with other types of pacemakers and is self-contained.43 Some of the disadvantages of placing this particular type of pacemaker during AV node ablation include device dislodgement, electrical interference, and dangerous conductive heating of tissue near the device from the ablation. The clinicians in the case series did not experience any complications with placement of the wireless pacemakers

17 nursece4less.com nursece4less.com nursece4less.com nursece4less.com during ablation and the patients safely underwent their procedures successfully.44

Pacemaker placement typically involves minor surgery to place the device into the chest, as mentioned above, and it may also be placed in the abdomen; and, the pacemaker wires are connected to the heart. When there are complications involving a pacemaker, related to the device itself, such as dislodgement of the wires or electrodes, the issue must be fixed right away to prevent a serious arrhythmia.

Cardiac resynchronization therapy (CRT) is a type of pacing that can be used to stimulate the heart to contract when the rate falls too low. The device used with this type of therapy is called a biventricular pacemaker and it is most commonly implemented among patients with heart failure. A study published in the Journal of the American College of examined the use of CRT combined with AV node ablation among subjects with heart failure who had also developed atrial fibrillation. The results of the combination of CRT with ablation were then compared to outcomes of subjects who had instead used antiarrhythmic drugs as treatment for their heart conditions. The study showed that the long-term survival of patients who underwent CRT with AV node ablation was very similar compared to those with sinus rhythm. Alternatively, the mortality rate was higher among patients who treated their AF with antiarrhythmic drugs only.73

Most patients who undergo AV node ablation with pacemaker placement are required to take anticoagulant drugs for several weeks before the procedure, as the risk of thrombosis is high.

18 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Electrical Mapping

Electrical mapping is a procedure performed to determine the locations in the heart where arrhythmias begin. The process of mapping may be performed during the ablation procedure or as a separate method prior to the actual ablation. To perform electrical mapping, a catheter is inserted in a manner similar to the process used for catheter ablation. The catheter is inserted and threaded to the heart. The tip of the catheter has a sensor that is able to sense electrical activity within the heart once it reaches the atrium. The electrical activity sensed by the catheter is then transmitted back to a monitor for the health clinician to better understand the origin of abnormal electrical signals in the cardiac conduction system.74

When mapping is performed during an ablation procedure, a mapping catheter may be inserted into one or more areas of the heart to assess electrical activity. The data obtained from the mapping catheter is transmitted to an electrogram, which allows the electrophysiologist to assess for patterns of electrical activity within the heart. If an area has already been ablated and abnormal electrical activity remains, the clinician can return to the area identified and ablate more tissue before removing the catheter.71

The mapping catheter is used to check for electrical isolation, which means that it determines whether electrical activity remains or has been lost. For example, during pulmonary vein isolation, the electrogram may indicate that the area of the pulmonary vein that was ablated is showing no electrical activity, meaning that the electrical activity in the pulmonary vein was isolated. After electrical isolation has been identified, it will need to be monitored for a period of time to confirm that the condition will remain. The mapping catheter will remain in place to allow the clinician to continue to

19 nursece4less.com nursece4less.com nursece4less.com nursece4less.com monitor the affected sites within the heart. When the clinicians can ensure that isolation is ongoing and no further areas require ablation, the intracardiac catheters can be removed.

Ablation may be preceded with an to determine the location of the source of the arrhythmia. An electrophysiology (EP) study gives a greater representation of the cardiac conduction cycle and allows the health clinician to isolate problematic areas that can be treated through ablation. The procedure is performed in the catheterization lab or an electrophysiology suite. The patient is usually sedated for the study and an anesthesia clinician may remain present throughout.

During the EP study, one or more catheters are inserted into the femoral vein in the groin and are then threaded up to the heart, guided by fluoroscopy. Once the catheter reaches the heart, the clinician can move the tip of the catheter slightly to analyze electrical signals from various locations. Electrodes are placed on the patient’s chest and back prior to the catheterization, which sends messages and records information when the catheter reaches the heart. The clinician may also insert different catheters to other parts of the heart to see how the body responds. The data is recorded to determine the source of the arrhythmia.

The EP study can help to determine the location of the pacemaker cells so that the tissue can be destroyed through ablation. When a patient has had a heart attack, a congenital anomaly, or underlying heart disease, the damage and scarring that causes the pacing to occur from another location within the heart may be apparent.

20 nursece4less.com nursece4less.com nursece4less.com nursece4less.com The study not only determines the location and source of the arrhythmia, it helps the clinician to better determine the patient’s overall risk of cardiac events and whether some antiarrhythmic medications may be more effective than others for treatment. If the EP study helps to determine that ablation would be beneficial for the patient, the patient may stay in the procedure room with sedation already on board and continue directly with the ablation. In some cases, the EP study identifies a problem but the clinician may determine that another type of treatment would be better, such as pacemaker placement or prescription antiarrhythmic medications. If the process does not proceed to ablation, the patient is taken to recovery and the alternative course of treatment will be started instead.40

A study by Nedios, et al., in the Journal of Atrial Fibrillation investigated contemporary mapping systems that provide three-dimensional reconstruction of the heart from the data collected through the mapping catheter.75 The electrogram is still used as part of voltage mapping, which displays electrical information. Additionally, the systems determine electrical information at specific points within the heart, color-code the information, and build a three-dimensional model of the tissue that displays areas of pacing and electrical impulse generation on a monitor.75 Some systems also use information gained from the catheter tip within the heart and communicate the data to sensors placed on the skin. This allows the information to be transmitted from multiple intracardiac catheters, rather than only one mapping catheter. It also reduces the overall length of the procedure and requires less exposure to radiation.

Whether the mapping is performed in isolation in the EP suite or is done as part of catheter ablation, cardiac mapping can lead health clinicians to better determine the locations of where arrhythmias are being generated, reducing

21 nursece4less.com nursece4less.com nursece4less.com nursece4less.com the need to induce the arrhythmia during the ablation procedure. With new technology available, health clinicians can continue to offer advanced methods of investigating the sources of cardiac arrhythmias through mapping.

Recovery Phase

A significant part of the recovery period following ablation consists of monitoring the patient to ensure that he/she stays safe and that complications are minimal. Some of this process involves monitoring patient activity while the sedative medications subside. Because the sedatives can make a person feel sleepy, there will need to be continuous monitoring until the patient is fully awake. The health clinician will typically use a hemodynamic monitor to ensure that the patient’s vital signs are normal and that adequate oxygenation occurs.

Occasionally, some patients may need supplemental oxygen during the recovery period because sedative agents can depress respiratory function. If a patient was not using supplemental oxygen prior to ablation, he/she can often be weaned off by the end of the recovery period. Importantly, the patient’s heart rate and rhythm will be monitored through a continuous ECG to ensure that normal sinus rhythm remains after the actual procedure. It is not uncommon for some patients to exhibit transient heart rhythm abnormalities after ablation, including extra beats or even brief episodes of atrial fibrillation while the heart tissue is recovering.

The ablation catheter is removed after the procedure, although the sheath may be left in place for a period until the patient is further along in the recovery period. After the catheter is removed, direct pressure is applied to the catheter site to prevent excess blood loss or hematoma formation. The

22 nursece4less.com nursece4less.com nursece4less.com nursece4less.com puncture site needs to be kept immobile during recovery to promote clot formation at the insertion spot. As an example, if the catheter was inserted into the femoral vein of the right groin, the patient may need to refrain from moving the right leg for a period during recovery.

The amount of time that the patient needs to keep still can vary but sometimes it can last for 6 to 8 hours. The health clinician should repeatedly assess the puncture site during recovery to ensure that the area is dry and there is no swelling or bleeding, although a small amount of bruising at the site is normal. Additional assessments may include checking pulses in the lower leg and foot of the affected limb, as well as assess the limb skin color and temperature. Any signs of limb ischemia should be reported immediately to the health clinician.

Applying pressure to the site of catheter insertion is important to prevent excess bleeding. A nursing or nursing assistant for the patient may provide manual pressure at the puncture site. Alternatively, there are devices created specifically for applying direct pressure that can be employed. Examples of compression devices include FemoStop and Safeguard, which cover the insertion site and stay in place during patient recovery. The devices have systems in which the pressure applied to the site can be increased or decreased to compress the femoral vessel and prevent significant blood loss.47 These types of devices are convenient because they reduce the need for extra personnel to provide manual direct pressure.

Patients recovering from catheter ablation may complain of some pain at the puncture site where the catheter was inserted. They may also experience some chest pain that can last for a couple of days. The chest pain is related

23 nursece4less.com nursece4less.com nursece4less.com nursece4less.com to the catheter advancement and destruction of tissue within the heart and should resolve with mild analgesic medications.

With epicardial ablation, the patient may complain of pain in the chest and at the site of catheter insertion under the rib cage. Following epicardial ablation, the patient may need medication to prevent infection in the pericardium. There is a small possibility that organisms can be introduced into the area around the heart, causing pericarditis. The amount of fluid in the pericardium will noticeably increase and the patient could be at greater risk of cardiac tamponade. During recovery, the patient may receive anti- inflammatory medications such as aspirin, colchicine, or ibuprofen to reduce the risk of swelling after the catheter ablation. A prophylactic antibiotic may also be prescribed, which the patient may start to take during recovery. Significant pain and inflammation from pericarditis may also necessitate administration of steroids such as prednisone.

Most patients are given a prescription for anticoagulant drugs such as warfarin to take in the months following ablation. When an anticoagulant is prescribed, periodic laboratory testing will be needed to ensure that the medication dose is at a therapeutic level. The medical clinician will adjust the dose to increase or decrease the amount based on blood tests, which usually includes an international normalized ratio (INR). Before discharge, the patient will also be given instructions for when to return for a follow-up appointment.

After the patient has completed the recovery period, he/she may be discharged to home if the procedure was performed as an outpatient procedure; however, this dismissal time is often after several hours of recovering or even the next day. There are usually few restrictions for the

24 nursece4less.com nursece4less.com nursece4less.com nursece4less.com patient after being discharged, but depending on the patient’s overall health status and the outcome of the procedure, the patient may need to limit some activities.

Risks Associated With Cardiac Ablation

As with other techniques used to treat cardiac arrhythmias, ablation also carries some risks to the patient. Although the procedure is performed under closely monitored conditions and measures are taken to minimize risks, the patient may still experience some problems. The risks that can occur with cardiac ablation are associated with the actual process itself, the medications used throughout the procedure, and the potential for hemorrhage afterward.

Some patients are at higher risk of developing complications associated with ablation because of their health status or due to factors that they cannot modify. Advancing age, for example, can increase a person’s risk of complications when having an ablation, as older age causes changes within the structure of the heart that could increase the risk of arrhythmias. Some people struggle with electrolyte abnormalities that can also increase the risk of complications. An abnormal potassium level, for example, can significantly increase the risk of arrhythmia, thus complicating the entire procedure. Even the time of day that the procedure is performed may have an effect on whether complications later develop. One study has noted that patients who underwent ablation procedures that started after 2 pm were more likely to have complications when compared to those who had earlier starting times.41

Because ablation involves catheter insertion, there is always a risk of infection or bleeding at the insertion site. There may be some bruising or swelling at the actual puncture site and hematoma is a danger. Whenever

25 nursece4less.com nursece4less.com nursece4less.com nursece4less.com is performed, there is a risk of bleeding from the insertion site; because this is considered a common potential complication, staff who work in the catheterization lab are trained to recognize signs of bleeding and to take steps to prevent hemorrhage. The insertion site is often a larger vessel that can bleed significantly if a blood clot does not form. When the catheter sheath is removed, the clinician must provide direct pressure for a time and the insertion site must be checked routinely during the recovery period, to ensure that the area is not bleeding excessively.

Hematoma formation most commonly occurs in the groin following cardiac catheterization procedures such as ablation. Hematoma sometimes occurs at the catheter insertion site when the blood vessel is damaged with insertion or removal of the catheter. Slow blood clot formation, blood vessel leaking, and blood pooling in the surrounding tissue can occur, causing bruising, swelling, and tenderness. The size of the hematoma can vary, depending on the overall rate of blood loss, and may appear as a small, discolored lump at the site of entry. A hematoma can be managed with direct pressure to the site to promote coagulation and to prevent further blood loss. Once the hematoma develops, however, it may take days or weeks for the bruising and swelling to fully resolve.

The risks associated with PVA are relatively minor; there is some risk of bleeding with catheter insertion, although this particular risk is commonly noted with most other procedures that take place in the catheterization lab. Because there is a puncture between the right and left atria during PVA, there is a risk of bleeding from that site as well, including tamponade if blood collects in the tissue directly surrounding the heart. Heparin is used during the procedure to prevent blood clots from forming, but the use of heparin with any invasive procedure also increases the risks of bleeding

26 nursece4less.com nursece4less.com nursece4less.com nursece4less.com during and immediately after the process. Therefore, it is imperative that all clinicians recognize and understand the risks of this particular type of ablation.

The patient who undergoes ablation is also at greater risk of developing an infection, which if left untreated, could become widespread and could lead to sepsis. Infection may develop when bacteria on the skin or the tissues surrounding the catheter insertion site are introduced into the puncture site with catheter placement. Although the insertion site is always cleansed prior to the procedure, there is still a risk of the introduction of various microorganisms that can cause an infection. An infection that develops at the catheter insertion site may be manifested as redness, slight swelling, purulent drainage, and tenderness. Depending on the extent of the infection, it may need treatment through topical or systemic antibiotics to prevent its spread.

An even more serious type of infection that can develop as a result of cardiac ablation is endocarditis, which develops when the becomes infected and inflamed. Recall that the endocardium is the innermost layer of the heart. Microorganisms can attach to the endocardium when they reach the heart through the bloodstream after being introduced through some type of opening into the circulatory system. The growth of infection within the heart can damage the different cardiac chambers as well as the heart valves, and the heart will be unable to contract normally. Infective bacterial endocarditis is the most common type of infection, caused by bacteria that invades the bloodstream and the heart tissue, however fungal infections can also cause endocarditis.

27 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Patients who develop endocarditis experience symptoms that are connected with the effects of the infection on the heart’s ability to contract. As a result of the damage caused to the heart, it does not contract normally and circulation is diminished, causing a number of symptoms, including overall fatigue and weakness, hypoxia and shortness of breath, and muscle or joint pain. The patient may also experience some of the more general symptoms related to infection, including fever, chills, night sweats, and decreased appetite.

One case study published in the European Heart Journal discussed a case of an older adult patient who had undergone radiofrequency ablation for the treatment of atrial fibrillation and AV block. Approximately four weeks after the procedure, the patient was seen for hemiparesis, altered mental status, upper gastrointestinal (GI) bleeding, and fever. After several tests, it was discovered that the patient had a streptococcal infection on a thrombus that was growing in the left atrium. The patient also had suffered from an atrioesophageal fistula as a result of the ablation procedure, which is a rare complication. The fistula develops when a connection occurs between the esophagus and the atrium following the procedure. In this case, the patient had developed a fistula after ablation, which led to an air embolism that traveled to the brain and that caused the neurological symptoms. Ultimately, the patient did not recover from the many complications the occurred as a result of the ablation procedure.37 Although a case such as this is quite rare, it is important to consider how various complications can actually compile to become a life-threatening situation.

The catheter tip, as it is moved through the heart, could potentially damage some of the cardiac tissue, causing perforation of the heart wall. This can lead to cardiac tamponade, in which fluid collects in the pericardium

28 nursece4less.com nursece4less.com nursece4less.com nursece4less.com surrounding the heart and compresses it to the point that it is not able to contract normally. Hemopericardium is a similar condition that can also occur as a possible complication of ablation. When hemopericardium develops, blood collects in the pericardial sac, in a situation that is similar to a pericardial effusion. Both pericardial tamponade and hemopericardium can quickly become life-threatening conditions, requiring rapid drainage through to relieve the extra pressure and compression of the heart.

A study by Hamaya, et al., in the journal EP Europace investigated instances of cardiac tamponade development due to ablation as treatment for AF. Overall, the study evaluated 5222 cases of cardiac ablation and found that cardiac tamponade developed in 51 cases, constituting a 0.98 percent incidence. Of these, over 86 percent of patients required pericardiocentesis as treatment and two patients (3.9 percent) required surgery for further treatment, with one of these patients ultimately dying from complications.38 While these may appear to be low numbers for such a significant condition as cardiac tamponade, the risk of this situation developing when cardiac ablation is performed must be recognized to enable the health clinician to take measures to decrease the risk.

Some patients are at higher risk of developing blood clots after cardiac ablation. When the procedure is performed for the treatment of AF, the increased risk is already present. The ablation process further raises the risk of thromboembolism when the catheter dislodges a thrombus. A blood clot can also form at the tip of the catheter either during ablation or if the patient has undergone a prior EP study. A patient who has undergone ablation will most likely need anticoagulant medications for several weeks afterward to reduce the risk of blood clots.

29 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Although ablation is performed to resolve an arrhythmia, the damage and scarring within the heart’s tissues could cause another arrhythmia to develop instead. In some cases, a patient may be healed of an offending arrhythmia only to acquire another. When this happens, the patient may experience new onset of dizziness or syncope and may need pacemaker placement or antiarrhythmic medications to control the rate and rhythm. Often, a new arrhythmia is a temporary occurrence in the immediate recovery period that resolves on its own and is benign overall.40 However, because of tissue damage, the heart’s electrical conduction system could be permanently altered through ablation, causing a new abnormality in the rhythm.

An electrical storm is a condition in which the rhythm of the heart becomes unstable and, over a short period of time, the patient experiences clusters of life-threatening arrhythmias, including and/or . It is loosely defined as a condition in which a person has more than 2 separate episodes of either of these rhythms within 24 hours.42 It appears to occur more often among patients who already have implantable cardioverter/defibrillators, but it can also happen after a procedure such as cardioversion or ablation.

Management of electrical storm can be complex, and some elements that have been pursued have later been found to be unsuccessful. Adequate treatment often involves treating the contributing condition and isolating the specific cause. Many clinicians have had success with the antiarrhythmic drug amiodarone or with a beta blocker such as propranolol. Catheter ablation is a commonly used treatment of electrical storm because it has been shown to interrupt some of the mechanisms that cause the tachyarrhythmias. Ablation may be beneficial in cases where the arrhythmia otherwise does not respond to other forms of treatment.

30 nursece4less.com nursece4less.com nursece4less.com nursece4less.com A study by Peichl, et al., and published in Circulation: Arrhythmia and Electrophysiology investigated many of the general risks associated with cardiac ablation by reviewing the procedures for 548 patients who electively underwent the procedure between 2006 and 2012.41 The study assessed the presence of complications that developed within a month or less following cardiac ablation. In this study, the most common complications were related to the access site, comprising 3.6 percent. Vascular complications that occurred included femoral arteriovenous fistula, femoral pseudoaneurysm, and groin hematoma following the procedure. A total of three (0.4 percent) patients suffered from complications related to perforation of the heart wall, including tamponade and hemopericardium. Other complications that were noted in the study included thromboembolic events (stroke during the procedure, transient ischemic attack, and systemic embolism), damage to the conduction system (development of AV block or left bundle branch block that eventually led to heart failure), and general complications (pericarditis, right lead dysfunction, and CPR required during the procedure).41

Overall, the study showed that patients were more likely to experience complications from ablation when they underwent the procedure for ventricular tachycardia related to structural heart disease compared to those with idiopathic ventricular tachycardia. Heart disease can sometimes cause enough damage within the heart to cause an arrhythmia such as ventricular tachycardia. Alternatively, with the idiopathic condition, there is no structural damage present from heart disease that would have contributed to the arrhythmia.

Catheter ablation is typically much more successful in managing idiopathic arrhythmias compared to those caused by structural heart disease. Often, patients with structural heart disease require more extensive procedures,

31 nursece4less.com nursece4less.com nursece4less.com nursece4less.com which may better explain why complications are more common in these cases. Patients in this particular study also required fewer repeat ablation procedures when idiopathic ventricular tachycardia was present versus structural heart disease.41

Although catheter ablation is an established treatment with high rates of success, there are still risks associated with the procedure. It is less invasive when compared to an open surgery, but the catheter insertion can still elicit negative responses or uphold patterns of disease within the body.

Cardiac Ablation Success Rate

The overall success of cardiac ablation typically depends on the arrhythmia being treated and a patient’s general state of health. Some arrhythmias may respond more to ablation and the treatment is successful for longer periods without recurrence when compared to others. Patients who have long- standing arrhythmias may be more likely to experience recurrence of the arrhythmia when compared to those who do not. For instance, a patient with paroxysmal AF may have greater success with treatment through ablation when compared to someone who has persistent AF. In fact, current guidelines have established catheter ablation as a standard form of treatment to successfully manage paroxysmal atrial fibrillation.48

Mortality rates following cardiac ablation may be higher for some patients, particularly when underlying heart disease is present. In the study previously mentioned by Peichl, et al., there were no patients with idiopathic ventricular tachycardia who died within 30 days following their ablation procedures.41 Alternatively, five patients with structural heart disease died within seven days following their procedures. Many of the reasons for these deaths were related to procedural complications (cardiac tamponade due to

32 nursece4less.com nursece4less.com nursece4less.com nursece4less.com perforation of the heart wall during the procedure, for instance), although there were some patients with such significant heart disease that death was foreseen. Approximately 53 percent of the patients who died following the procedure developed a recurrence of their arrhythmias before their deaths.41

A study by Wynn, et al., published in Open Heart analyzed cardiac ablation procedures for success rates. The study reviewed the data of 188 patients who had undergone catheter ablation for the treatment of persistent AF and followed their outcomes over a period of six years. Several patients required more than one ablation procedure; the average number was 1.75 procedures per patient with a range of 1 to 4 total. In all, 75 percent of patients experienced recurrence of AF when they underwent ablation one time, and 90 percent of patients experienced arrhythmia recurrence after their final procedure. Of these patients, 91 percent had arrhythmias that recurred within two years of their last procedure. The study also showed a low incidence of complications from the catheter ablation (approximately 2 percent of procedures), which included pericardial effusion, aortic puncture, phrenic nerve paralysis, and femoral artery pseudoaneurysm, however, no patients experienced stroke or died due to procedure-related causes.38

Though various study outcomes may differ somewhat from these exact results, other data has also shown that recurrence of atrial fibrillation is relatively high when patients are being treated for persistent atrial fibrillation. Because more time has passed since the advent of catheter ablation, clinicians have gained more experience and expertise with performing ablation procedures. As a result, success rates can be partly based on years of experience in determining what situations were more successful compared to times that were not effective, and modifications can be made accordingly.

33 nursece4less.com nursece4less.com nursece4less.com nursece4less.com Another study published in the journal Heart Rhythm assessed the long-term outcomes of patients who had undergone PVA isolation for AF. The study assessed the outcomes of patients one year after their procedures and then again at several time points up to and including 10 years’ post-procedure. The study showed that after approximately 3 ½ years post-ablation, almost 22 percent of patients experienced at least one episode of recurrent AF but there were no other complications or long-term problems associated with this. At 5 and 10 years, the rates of recurrence were 16.3 and 29.8 percent, respectively. A little less than one-third of these patients had episodes that self-resolved without intervention, while the remaining patients required either antiarrhythmic medication or another ablation to control AF recurrence.49 Overall, ablation is often a successful procedure in the immediate time following the treatment, but the risks continue to increase over time as to whether an affected patient will develop a recurrence of previous atrial fibrillation.

Summary

There are several different types of ablation procedures that may be performed as treatment of arrhythmia. The type of procedure chosen is based on the type of arrhythmia, how long the patient has had the condition and whether it causes harmful symptoms, and the person’s overall health condition. The potential risks associated with ablation must be taken into account on a case-by-case basis for individual patients. Most people require ablation for the treatment of tachyarrhythmias, including atrial fibrillation or atrial flutter, as well as some of the other supraventricular tachycardias.

Cardiac ablation is a mildly invasive procedure that usually involves a rapid recovery period and few adverse effects. Many patients, particularly those with arrhythmias that are causing frequent symptoms, take routine

34 nursece4less.com nursece4less.com nursece4less.com nursece4less.com antiarrhythmic medications that may be stopped for a short period before the procedure and resumed afterward either at the same or decreased dose. Anticoagulant drugs to prevent thrombosis and insertion of a permanent pacemaker to treat severe bradycardia corresponding to an ablation procedure may be needed.

Cardiac ablation is often successful immediately following treatment, however over time an affected patient may develop a recurrence of previous atrial fibrillation. As a treatment option, cardiac ablation that has been shown to reduce or eliminate cardiac arrhythmias in many cases. Clinicians need to understand both benefits and risks of ablation for different types of atrial arrhythmias to fully inform patients of their options and possible outcomes of treatment.

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35 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 1. Cardiac ablation generally involves inserting a catheter into the body and threading it through the circulatory system

a. to the heart. b. to the lungs. c. to the left or right carotid artery. d. up to the superior vena cava.

2. The tip of the catheter has an electrode that sends radiofrequency energy through the tip of the catheter

a. to stimulate the heart. b. to remove scarring that may be causing arrhythmia. c. to break up blood clots. d. to damage the offending tissue.

3. Prior to an ablation procedure, a clinician may schedule a patient for a transesophageal echocardiogram (TEE) to

a. determine if catheterization is possible. b. locate a potential blood clot. c. identify scar tissue within the heart. d. locate the source of an arrhythmia.

4. A patient preparing for a cardiac ablation will typically take an anticoagulant, such as ______, because the risk of thrombus can be high.

a. warfarin b. clopidogrel c. propofol d. remifentanil

5. Most patients require enough anesthetic to produce ______throughout the cardiac ablation procedure.

a. general anesthesia b. mild sedation c. conscious sedation d. anxiolysis

36 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 6. True or False: Unlike cardioversion, a patient preparing for cardiac ablation does not undergo an ECG because the clinician can determine the location of the arrhythmia during the catheterization process.

a. True b. False

7. ______ablations are performed by inserting a catheter through the skin under the rib cage in the chest wall and threading it into the area around the heart.

a. Epicardial b. Pulmonary vein antrum (PVA) isolation c. Endocardial d. Atrioventricular node

8. ______is one of the more common techniques used in the treatment of paroxysmal atrial fibrillation.

a. Cardiac resynchronization therapy (CRT) b. Pulmonary vein antrum (PVA) isolation ablation c. Atrioventricular (AV) node ablation d. Endocardial ablation

9. Electrical mapping is a procedure performed to determine the locations in the heart where

a. normal cardiac rhythm is present. b. scar tissue is located. c. arrhythmia may be induced. d. arrhythmias begin.

10. Once cardiac ablation is completed, the following procedures are followed:

a. the sheath covering the catheter is removed first. b. direct pressure to the catheter site is avoided. c. the catheter is removed. d. scar tissue is excised.

37 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 11. Following epicardial ablation, the patient may need medication to prevent infection in

a. the carotid artery. b. the right atria. c. the pericardium. d. the left atria.

12. True or False: During a cardiac ablation procedure, the electrophysiologist may attempt to induce the arrhythmia if the patient is not already exhibiting the abnormal cardiac rhythm.

a. True b. False

13. A patient with an abnormal potassium level can significantly increase the risk of ______during the ablation procedure.

a. cell destruction b. tissue scarring c. thrombus d. arrhythmia

14. Following an ablation procedure, if a hematoma develops,

a. it may take days or weeks to fully resolve. b. direct pressure to the site should be avoided. c. an anticoagulant should be administered. d. All of the above

15. A serious type of infection that can develop to the innermost layer of the heart as a result of cardiac ablation is called

a. pericarditis. b. endocarditis. c. fasciitis. d. arteritis.

38 nursece4less.com nursece4less.com nursece4less.com nursece4less.com CORRECT ANSWERS:

1. Cardiac ablation generally involves inserting a catheter into the body and threading it through the circulatory system

a. to the heart.

“Ablation involves inserting a catheter into the body and threading it through the circulatory system to the heart.”

2. The tip of the catheter has an electrode that sends radiofrequency energy through the tip of the catheter

d. to damage the offending tissue.

“The tip of the catheter has an electrode that targets the affected node or area within the heart that is causing the arrhythmia. The electrode sends radiofrequency energy through the tip of the catheter to damage the offending tissue, heating it to enough intensity that it causes a burn to produce tissue scarring.”

3. Prior to an ablation procedure, a clinician may schedule a patient for a transesophageal echocardiogram (TEE) to

b. locate a potential blood clot.

“Prior to an ablation procedure, a clinician may schedule a patient for a transesophageal echocardiogram (TEE) to locate a blood clot if one is present in the heart or surrounding tissue.”

4. A patient preparing for a cardiac ablation will typically take an anticoagulant, such as ______, because the risk of thrombus can be high.

a. warfarin

“A patient typically requires anticoagulation for several weeks before and after the ablation procedure, as risk of thrombus can be high. This is accomplished by prescribing an anticoagulant such as warfarin.”

39 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 5. Most patients require enough anesthetic to produce ______throughout the cardiac ablation procedure.

c. conscious sedation

“Most patients require enough anesthetic to produce conscious sedation....”

6. True or False: Unlike cardioversion, a patient preparing for cardiac ablation does not undergo an ECG because the clinician can determine the location of the arrhythmia during the catheterization process.

b. False

“As with cardioversion, the patient will first undergo an ECG so that the clinician can determine the abnormal heart rate and rhythm....”

7. ______ablations are performed by inserting a catheter through the skin under the rib cage in the chest wall and threading it into the area around the heart.

a. Epicardial

“With epicardial ablation, ... catheters are placed through the skin under the rib cage in the chest wall and threaded to enter the space around the heart for the ablation.”

8. ______is one of the more common techniques used in the treatment of paroxysmal atrial fibrillation.

b. Pulmonary vein antrum (PVA) isolation ablation

“(PVA) isolation ablation is one of the more common techniques used in the treatment of paroxysmal atrial fibrillation.”

9. Electrical mapping is a procedure performed to determine the locations in the heart where

d. arrhythmias begin.

“Electrical mapping is a procedure performed to determine the locations in the heart where arrhythmias begin.”

40 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 10. Once cardiac ablation is completed, the following procedures are followed:

c. the catheter is removed.

“The catheter is removed after the procedure, although the sheath may be left in place for a while until further along in the recovery period. After the catheter is removed, direct pressure is applied to the catheter site to prevent excess blood loss ...”

11. Following epicardial ablation, the patient may need medication to prevent infection in

c. the pericardium.

“Following epicardial ablation, the patient may need medication to prevent infection in the pericardium.”

12. True or False: During a cardiac ablation procedure, the electrophysiologist may attempt to induce the arrhythmia if the patient is not already exhibiting the abnormal cardiac rhythm.

a. True

“During a cardiac ablation procedure, the electrophysiologist may attempt to induce the arrhythmia if the patient is not already exhibiting the abnormal cardiac rhythm.”

13. A patient with an abnormal potassium level can significantly increase the risk of ______during the ablation procedure.

d. arrhythmia

“An abnormal potassium level ... can significantly increase the risk of arrhythmia, thus complicating the entire procedure.”

14. Following an ablation procedure, if a hematoma develops,

a. it may take days or weeks to fully resolve.

“A hematoma can be managed with direct pressure to the site to promote coagulation and to prevent further blood loss. Once the hematoma develops, however, it may take days or weeks for the bruising and swelling to fully resolve.”

41 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 15. A serious type of infection that can develop to the innermost layer of the heart as a result of cardiac ablation is called

b. endocarditis.

“An even more serious type of infection that can develop as a result of cardiac ablation is endocarditis, which develops when the endocardium becomes infected and inflamed. Recall that the endocardium is the innermost layer of the heart.”

References

The reference section of in-text citations includes published works intended as helpful material for further reading. [References are for a multi-part series on CARDIOVERSION AND ABLATION].

1. Mitchell, L. (2017). Atrial fibrillation (AF). Retrieved from http://www.merckmanuals.com/professional/cardiovascular- disorders/arrhythmias-and-conduction-disorders/atrial-fibrillation-af 2. National Heart, Lung, and Blood Institute. (n.d.). How the heart works. Retrieved from https://www.nhlbi.nih.gov/health/health- topics/topics/hhw/electrical 3. Thompson, A. (2015). Atrial fibrillation. JAMA 313(10): 1070. Retrieved from https://jamanetwork.com/journals/jama/fullarticle/2190988 4. Emdin, C., et al. (2017). Usual blood pressure, atrial fibrillation and vascular risk: evidence from 4.3 million adults. International Journal of Epidemiology 46(1): 162-172. Retrieved from https://academic.oup.com/ije/article/46/1/162/2617172 5. Cantillon, D. (2014). Atrial fibrillation. Retrieved from http://www.clevelandclinicmeded.com/medicalpubs/diseasemanageme nt/cardiology/atrial-fibrillation/ 6. Howlett, P., et al. (2015). Diagnosing paroxysmal atrial fibrillation: are biomarkers the solution to this elusive arrhythmia? BioMed Research International, Article ID 910267. Retrieved from https://www.hindawi.com/journals/bmri/2015/910267/ 7. Nattel, S., Harada, M. (2014). Atrial remodeling and atrial fibrillation: recent advances and translational perspectives. Journal of the American College of Cardiology 63(22); 2335-2345.

42 nursece4less.com nursece4less.com nursece4less.com nursece4less.com 8. Camm, J. (2015). NOACS in AF patients undergoing cardioversion. [PowerPoint]. St. George’s University of London. 9. Burns, E. (2017) Atrial flutter. LITFL ECG library. Retrieved from https://lifeinthefastlane.com/ecg-library/atrial-flutter/ 10. Fogors, R. (n.d.). Cardiac anatomy and physiology – the cardiac action potential. The EP Lab.com. Retrieved from http://www.theeplab.com/B-The-Members-Center/C-Cardiac- AnatomyPhysiology/F-Action-Potential/CF00-Action-Potential.php 11. Ikonnikov, G. and Yelle, D. (2009). Cardiac conducting system. Clin Anat. 22(1): 99-113. Retrieved from http://www.pathophys.org/physiology-of-cardiac-conduction-and- contractility/ 12. National Heart, Lung, and Blood Institute. (n.d.). Arrhythmia. Retrieved from https://www.nhlbi.nih.gov/health-topics/arrhythmia 13. Atlantic Cardiology Group, LLP. (2018). Atrial arrhythmias. Retrieved from http://www.mccardio.com/handler.cfm?event=practice,template&cpid =3330 14. Conen, D., et al. (2012). Premature atrial contractions in the general population. Circulation 2012; 126: 2302-2308. Retrieved from http://circ.ahajournals.org/content/126/19/2302 15. Mitchell, B. (2017). Atrial flutter. Retrieved from http://www.merckmanuals.com/professional/cardiovascular- disorders/arrhythmias-and-conduction-disorders/atrial-flutter 16. Aksu, T., et al (2015). Radiofrequency ablation of typical atrial flutter via right jugular vein due to bilateral obstructed iliac veins in a patient with dilated cardiomyopathy. Case Reports in Cardiology, Article ID 401580, 3 pages. Retrieved from https://www.hindawi.com/journals/cric/2015/401580/ 17. Dewland, T., Glidden, D., Marcus, G. (2014). Healthcare utilization and clinical outcomes after catheter ablation of atrial flutter. PLOS One. Retrieved from http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0100 509 18. EKG.Academy.com. (2017). Junctional dysrhythmias – premature junctional complex (PJC) and junctional escape beats. Retrieved from https://ekg.academy/learn-ekg?courseid=314&seq=6 19. Nurses Learning Network. (2018). EKG interpretation. Retrieved from https://www.nurseslearning.com/courses/nrp/nrp1619/section%202/p 02.html 20. U.S. National Library of Medicine Genetics Home Reference. (2017). Wolff-Parkinson-White syndrome. Retrieved from https://ghr.nlm.nih.gov/condition/wolff-parkinson-white-syndrome

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