Electrophysiology study (EP) and ablation for

CARDIOLOGY | INTERVENTIONAL

Our image-guided procedures are minimally invasive meaning Your care safer procedures with quicker and easier recovery. lies within Clean, precise, proven. Treating arrhythmias What is an Electrophysiology (EP) study?

An electrophysiology (EP) study is used to diagnose an abnormal rhythm An EP study helps identify the location of the ’s abnormal electrical activity. problem and the treats the problem. The location and type of rhythm problem is useful to confirm if catheter ablation EP and/or catheter ablation procedures are carried out in a specially equipped is an appropriate treatment option for your patients’ condition. room called the EP lab (or catheter lab) at Intra within the Mercy Hospital, The EP study diagnoses your heart rhythm problem by: Epsom, Auckland. A cardiologist will be assisted by our team of nurses and other highly skilled personnel. 1) Recording Electrical Signals and ECGs Electrode sense electrical activity in various areas of the heart What is an abnormal heart rhythm? and measure how fast electrical impulses travel 2) Pacing the Heart An abnormal heart rhythm, or , is a change in either the speed or pattern of the heartbeat. During an arrhythmia, the heart may beat too slowly Electrode catheters are used to deliver tiny electrical impulses to pace called bradycardia, too rapidly, or irregularly called tachycardia. the heart. This means doctors can try to induce (bring on) certain abnormal heart rhythms whilst being observed under controlled In a healthy normal heart the rhythmic contractions depend on its conditions. To bring on an arrhythmia, medications may be given electrical system to conduct electrical impulses throughout the heart. through the IV line to speed up the heart.

The electrical impulse begins at the Sinoatrial (SA) Node, located in the right . The electrical activity spreads through the walls of the atria and causes them to contract. Pulmonary

The AV node is located between the atria and ventricles and acts like a gate that slows the electrical signal before it enters the ventricals. This delay gives atria time to contract before the ventricales.

His-Purkinje Network This pathway of fibres sends the impulse into the muscular walls of the and causes them to contract. Right Ventricle Left Ventricle

1 2 What is catheter ablation? Wolff-Parkinson-White Syndrome (WPW) • In WPW, an abnormal “bridge” of tissue connects the atria and the ventricles. Catheter Ablation is used for treating certain rapid heart rhythms called tachycardias. Although medications are frequently used to treat rapid heart • This extra pathway is called an accessory pathway and makes it possible for rhythms, they may be ineffective or cause side effects, and in addition must be electrical impulses to travel from the atria to the ventricles without going continued indefinitely. through the AV node. Surgery to treat arrhythmias is almost completely superseded by catheter • In people with WPW, an arrhythmia can get started when an impulse travels ablation because of the much lower risk. When successful, catheter ablation down the normal conduction pathway to the ventricles and then back up should permanently cure the problem your patient has been experiencing. through the accessory pathway to the atria. The mainstay treatment for serious arrhythmias ( with • If the impulse continues to travel in a circular pattern, it may cause the heart heart damage) are surgically implantable devices, but these are inappropriate to contract with each cycle, and may result in a very rapid heartbeat. for supraventricular tachycardias. • Some accessory pathways conduct impulses rapidly and thereby may allow very rapid and serious rhythms to occur.

Atrial Fibrillation (AF) • In AF, multiple circuits in the atria occur simultaneously, stimulating the heart in an uncoordinated fashion. As a result, the atria quiver quickly and ineffectively. • The loss of a co-ordinated beat may allow the blood to stagnate and form blood clots. • The AV node, which acts as a gate, allows only some of these impulses to travel down the electrical system to stimulate the ventricles. • As a result, the heart rhythm is irregular and usually, but not always rapid. Atrial fibrillation may recur periodically or it may be persistent.

Common tachycardia conditions treated with ablation include: Atrial Flutter (AF) • In atrial flutter there is a single, short circuit that conducts electrical impulses Supraventricular Tachycardia (SVT) rapidly around the inlet valve of the right ventricle. SVT is a general term describing a series of very rapid heartbeats that begin in • Usually every second beat is conducted from this abnormal circuit to the the upper chambers of the heart. Specific examples include: ventricles resulting in a heart rate of around 150 beats per minute. AV nodal re-entrant tachycardia (AVNRT) • This rhythm can often be difficult to treat with medication. (AVNRT) is the most common form of SVT. In this condition, two pathways exist • Similarly to atrial fibrillation, there can be a risk of blood clots forming in in the AV node. If an electrical impulse enters only one of the pathways, it the atria. may double back through the unused second pathway and start travelling in a circular pattern. This may cause the heart to contract with each cycle, and may • If the heart rate cannot be controlled there can be a risk of weakened result in a very rapid, regular heartbeat. heart muscle pumping function.

3 4 Ventricular tachycardia (VT) How to find Intra Epsom • Ventricular tachycardias arise from the major pumping chambers at the bottom of the heart. • VT is a more serious rhythm problem because it often occurs in a setting of previous heart damage (e.g. a heart attack) and may be best managed with an implanted defibrillator. • Sometimes with VT, the heart is otherwise healthy and the abnormal rhythms arise from an irritable trigger point. This trigger can often be localised and successfully ablated. 1st Floor, Mercy Hospital,

KHYBER PASS 98 Mountain Road, Epsom, OFF RAMP Auckland 1023, Gate 1. Benefits RD

KHYBER PASS RD The EP study and catheter ablation are relatively low-risk procedures. GILLIES AVE Key: Catheter ablations have high success rates and may permanently cure the OFF RAMP S problem your patient has been experiencing. In many cases, it means avoiding O Northbound motorway traffic

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T B a lifetime of medications and the chance to lead a normal life. H R E

R O Southbound motorway traffic

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IT RD W ILG G A What are the risks? M O Y Mercy TO RW Most patients who undergo an EP study or catheter ablation do not experience Hospital AY problems. The EP study and catheter ablation are “invasive” procedures that Intra

require the insertion of catheters into the body and therefore involves some risk. MOUNTAIN RD ALPERS AVE P: +64 9 630 1961 (office hours) This risk is small, and the procedure is considered relatively safe. P: +64 27 482 0763 (after hours) To learn more about a patients’ particular risks, your patient should discuss this ALBURY AVE F: +64 9 630 1962 with their cardiologist. E: [email protected] W: intracare.co.nz More information

GILLIES AVE MANUKAU RD To find out how to refer your patient and more information contact: OWENS RD E: [email protected] P: +64 9 630 1961 W: intracare.co.nz

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E: [email protected] W: intracare.co.nz