3/31/2015
What Is Cardiac Stress Testing?
Chad Morsch B.S., ACSM CEP
• Cardiac stress tests compare the coronary A Cardiac Stress Test is a test used to circulation while the patient is at rest with the measure the heart's ability to circulation observed during maximum physical exertion, showing any abnormal blood flow to respond to external stress in a the heart's muscle tissue controlled clinical environment. • This test can be used to diagnose ischemic heart disease, and for patient prognosis after a heart attack or procedure (CABG, STENT, etc.)
MODALITIES MODALITIES • Treadmill, Bicycle, or Arm Ergometer • Treadmill, Bicycle, or Arm Ergometer • The level of mechanical stress is progressively increased by adjusting the difficulty (incline, speed, or tension)
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MODALITIES MODALITIES • Treadmill, Bicycle, or Arm Ergometer • Treadmill, Bicycle, or Arm Ergometer • The level of mechanical stress is progressively • The level of mechanical stress is progressively increased by adjusting the difficulty (incline, increased by adjusting the difficulty (incline, speed, or tension) speed, or tension)
• Intravenous Pharmaceutical • Intravenous Pharmaceutical • Regadenoson, Adenosine, Persantine, or Dobutamine administered to patient through an IV
MODALITIES ABSOLUTE CONTRAINDICATIONS • Treadmill, Bicycle, or Arm Ergometer Stress Testing • The level of mechanical stress is progressively increased by adjusting the difficulty (incline, 1) Recent significant change in ECG (i.e. MI, ischemia, etc) speed, or tension) 2) Unstable angina 3) Uncontrolled cardiac arrhythmias causing symptoms • Intravenous Pharmaceutical 4) Severe aortic stenosis • Regadenoson, Adenosine, Persantine, or 5) Uncontrolled heart failure Dobutamine administered to patient through an 6) Acute pulmonary embolus IV 7) Acute myocarditis or pericarditis 8) Suspected/known dissecting aneurysm Blood pressure, heart rate, and EKG are analyzed for 9) Acute systemic infection abnormalities and improper response to exercise or simulated exercise
ABSOLUTE CONTRAINDICATIONS ABSOLUTE CONTRAINDICATIONS Regadenoson Adenosine and Persantine (Dipyridamole) 1) Any condition that would exacerbate bronchospasms (acute asthma, wheezing or congestion) 1) Any condition that would exacerbate bronchospasms 2) Use of dipyridamole or dipyridamole‐containing (acute asthma, wheezing or congestion) medications (e.g., Aggrenox) in the last 48 hours 2) HHiypotension, SSliystolic BP <90 mm Hg 3) Use of aminophylline in the last 24 hours 3) Use of dipyridamole or dipyridamole‐containing 4) Use of products containing methylxanthines as well as medications (e.g., Aggrenox) in the last 48 hours drugs containing theophylline in the last 12 hours 4) Ingestion of caffeine in last 12 hours 5) Ingestion of caffeine in last 12 hours 5) Advanced heart block 6) Hypotension, Systolic BP <90 mm Hg 7) Known hypersensitivity to adenosine or dipyridamole 8) Advanced heart block
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PATIENT ANALYSIS INDICATIONS FOR STOPPING A • How does the patient ambulate STRESS TEST • Has the patient done this test before Absolute 1) Drop in systolic BP of >10 mm Hg from baseline • Review past medical history pressure when accompanied by ischemia 2) Moderate to severe angina • Medications 3) Increasing nervous system symptoms (dizziness) 4) Signs of poor perfusion (cyanosis or pallor) • Listen to heart and lung sounds 5) Technical difficulties monitoring BP or EKG 6) Subjects desire to stop • Check blood pressure and heart rate 7) Sustained ventricular tachycardia 8) ST elevation > 1mm in leads without diagnostic Q‐ • Analyze the EKG waves (other than V1 or aVR)
Prepping The Patient
Prepping The Patient Prepping The Patient Obtain IV access Obtain IV access
You must have access to the bare chest • Lifting, unbuttoning or removing of shirt • Removal of a bra
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Prepping The Patient Prepping The Patient Obtain IV access Obtain IV access
You must have access to the bare chest You must have access to the bare chest • Lifting, unbuttoning or removing of shirt • Lifting, unbuttoning or removing of shirt • Removal of a bra • Removal of a bra
A Clean site is optimal!! A Clean site is optimal!! • Shaving of chest hair • Scratching of skin with sandpaper • Wiping skin with alcohol
Precordial Leads V1 –4th intercostal space immediately to the right of the sternum
V2 –4th intercostal space immediately to the left of the 12 Lead EKG Electrode Placement sternum
V3 – Directly between V2 and V4
V4 –5th intercostal space ‐ midclavicular line Limb Leads Right Arm V5 –5th intercostal space Left Arm midway between V4 and V6 Right Leg Left Leg V6 –5th intercostal space ‐ midaxillary line
Horizontal Plane
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IT’S NOT JUST A BUNCH OF SQUIGGLY LINES…THERE ARE WAVES!
P Wave –Atrial Depolarization QRS Complex –Ventricular Depolarization
T Wave –Ventricular Repolarization U Wave –Late Repolarization
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PR Interval ‐ .12 to .20 seconds QRS Interval ‐ .04 to .11 seconds
CAN YOU DEFINE NORMAL??
QT Interval –The time from the beginning of ventricular depolarization to the end of repolarization
NORMAL SINUS RHYTHM
Heart Rate ‐ between 60‐100 bpm
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BRADYCARDIA TACHYCARDIA
Heart Rate ‐ less than 60 bpm Heart Rate ‐ greater than 100 bpm
Premature Ventricular Contraction Premature Ventricular Contraction (PVC) (PVC)
• Most common of the ventricular arrhythmias • QRS duration must be at least 0.12 seconds • Isolated PVCs are common in normal hearts
BIGEMINY TRIGEMINY
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VENTRICULAR TACHYCARDIA VENTRICULAR TACHYCARDIA
• A run of three or more PVCs • Usually has a rate between 120 –200 bpm
Premature Atrial Contraction Premature Atrial Contraction (PAC) (PAC)
• PACs are common phenomena • A P wave is visible but differs from sinus P waves • Conduct normally to ventricles, normal QRS
PAROXYSMAL SUPRAVENTRICULAR PSVT TACHYCARDIA (PSVT)
• Has a regular rhythm with a HR of 150‐250 bpm • Narrow QRS • Onset is sudden and termination is just as abrupt • Valsalva techniques can break the arrhythmia • Advanced treatment with Adenosine or Cardioversion
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FIRST DEGREE AV BLOCK FIRST DEGREE AV BLOCK
• Caused by a prolonged delay in conduction at the AV node • PR interval of 0.2 seconds • Every QRS complex is preceded by a P wave
SECOND DEGREE AV BLOCK SECOND DEGREE AV BLOCK (MOBITZ TYPE I) (MOBITZ TYPE I)
• Also known as a Wenckebach • Usually due to a block within the AV node • Progressive lengthening of each successive PR interval until one P wave fails to conduct through the AV node and is therefore not followed by a QRS complex • Sequence then repeats itself
SECOND DEGREE AV BLOCK SECOND DEGREE AV BLOCK (MOBITZ TYPE II) (MOBITZ TYPE II)
• Usually due to a block below the AV node in the HIS bundle • Not all atrial impulses are transmitted to the ventricles • There is a presence of a dropped beat without progressive lengthening of the PR interval • Ratio of conducted beats to non‐conducted (P waves to QRS complex) beats can vary
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THIRD DEGREE AV BLOCK THIRD DEGREE AV BLOCK (COMPLETE HEART BLOCK) (COMPLETE HEART BLOCK)
• Complete AV dissociation • P waves and QRS complexes appear at regular intervals but have nothing to do with one another • Atria contract about 60‐100 bpm • Ventricles contract about 30‐45 bpm • Ventricular complexes will appear wide and bizarre like PVCs
ATRIAL FIBRILLATION ATRIAL FIBRILLATION
• Irregular rhythm • QRS will generally appear normal • No true P waves are distinguishable • Atrium contracting at over 300 bpm • Baseline appears to be undulating slightly
ASYSTOLE SO WHY DO I NEED TO KNOW ALL THIS?
HOW DOES THIS PERTAIN TO MY JOB?
10 3/31/2015
• Gating of myocardial perfusion patients • Gating of myocardial perfusion patients • Ejection Fraction
How it Works Ejection Fraction
The amount of blood in the left and right ECG ventricles pumped out with each heartbeat Gate Camera/ Computer
Frame 1 Frame 3 Frame 28
QUANTIFICATION
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• Gating of myocardial perfusion patients • Gating of myocardial perfusion patients • Ejection Fraction • Ejection Fraction
• Emergencies • Emergencies
•Second set of eyes
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QUESTIONS?
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