Contra-indications, Risks, and Data to Support …

1 1zHow safe is stress testing ?zContra-indicationszTermination CriteriaEllstad Chapt 5 ACSM Chapts 3-6 contra - indications , risks , andSafety Precautions for stress TestingData to Support stress TestingzSeattle Heart Watch Study asymptomatic persons with 2 or more CAD risk factors have a 15 x greater risk of developing CADzAmerican Heart Committee Recommends stress testing persons older than 40 or with CAD risk factors before beginning a vigorous exercise programACSM guidelines, pg 20 Low RiskModerateRiskHigh RIskModerateExercisenonoyesVigorousExerc isenoyesyesModerate exercise < 3-6 METS < 40-59% VO2maxVigorous exercise > 6 METS, > 60% VO2maxRisk Classifications pg 27zLow Risk men < 45, women < 55 yrs asymptomatic 0 or 1 CAD risk factorzModerate Risk Older 2 or more risk factorszHigh Risk signs, symptoms, or known CV, pulmonary, or metabolic diseases7 ACSM RISK FACTORS, pg 22zFamily historyzCigarette smokingzHypertensionzDyslipidemiazImpaired fasting glucosezObesityzSedentary Lifestyle7 ACSM RISK FACTORSzFamily history (m> 55, f> 65)zCigarette smoking (<6 mo)zHypertension (>140/90)zDyslipidemia (TC >200 mg/dL, LDL > 130 mg/dL, HDL < 40 mg/dL, or on lipid lowering meds)2 Risk Factors, fasting glucose (>100mg/dL)zObesity (>30 kg/m2, wg > 102cm m or 88cm f, w/h > m or f)zSedentary Lifestyle (<30 min/d moderate PA)Is stress testing Safe?

2 Z Safety is an important aspect in persons over 40 or with risk factors (Ellstad pg 86)z Even maximal testing is safe if the physician follows available guidelines (Ellstad pg 86) Know when to stop Know when not to startDeaths during stress Testsz1 in 10,000 (Rochimis and Blackburn) 170,000 tests in cardiac patients 75% of tests at ~ 75% HRmax 34% maximal testsz risks of serious complications seem reasonable, and with the use of established techniques and continuous monitoring can be minimized Ellstad pg 99 Risk during Maximal vs. Submaximal TestszNo further risk for maximal tests than submaximalzAssumes appropriate screening and monitoring of subjectsIRB proposal and Consent form issueszHow would you describe the risk for maximal stress testing to the IRB?zHow would you describe the risk of a maximal stress test to a research subject?zHow would you describe the risk of a maximal stress test to a patient being screened for CAD?

3 contra -IndicationszAbsolute contra - indications stress test should not be performed until the condition is stabilized or adequately treatedzRelative contra - indications may be tested only after careful evaluation of the risk/benefit ratio3 Conflicting Guidelines?zLegally, safe if you go with published standards zGo with laboratory standards Ellstad ACSM NASA Exercise Physiology Lab Rehabilation siteACSM Absolute contra - indications for testing pg 501. EKG change suggesting recent MI, severe ischemia, or other significant cardiac event2. Unstable angina 3. Uncontrolled cardiac arrhythmias causing symptoms4. Severe symptomatic aortic stenosisAbsolute contra - indications for testing , Symptomatic heart failure6. Pulmonary embolus or pulmonary infarction7. Acute myocarditis or pericarditis8. Suspected or known dissecting aneurysm9. Acute systemic infectionACSM Relative contra - indications for testing (pg 50)1.

4 Left main coronary stenosis2. Moderate stenotic valvular heart disease3. Electrolyte abnormalities4. Hypertension, >200/110 at rest5. tachyarrhythmias or bradyarrhythmiasRelative contra - indications for testing , Hypertrophic cardiomyopathy(other outflow tract obstructions)7. Neuromuscular, musculoskeletal, rheumatoid disorders exacerbated by exercise8. High-degree a-v blockRelative contra - indications for testing , metabolic disease (diabetes, thyroid) infectious disease (hepatitis) of physical impairment with inability to exercise4 AnginazCharacteristics Substernal Pain Precipitated by exertion Promptly relieved by rest or nitroglycerinzTypical angina (patients with all three characters)zAtypical angina (patients with 2)zNonanginal (patients with 1)(Roberts 97, pg 144)Stable vs. Non-Stable AnginazSilent angina ST depression but no symptomszStable angina occurs predictably with progressive exercise at approximately the same rate-pressure productzUnstable angina abrupt increase in frequency or occurrence at restAnginal Symptom Scalez+1 Light, barely noticablez+2 Moderate, bothersomez+3 Severe, very uncomfortablez+4 Most severe pain ever experienced(ACSM pg 107)A rating of 3 or a degree that would cause the patient to stopnormal daily activities or take a nitroglycerin tablet shouldbe the test stopping pointACSM Absolute indications for Terminating a Test (Box 5-2, pg 106)1.

5 SBP >10 mmHg from baseline with work rate and ischemia2. Moderate or severe angina (>3)3. nervous system symptoms (ataxia, dizziness, near syncope)4. Poor perfusion (cyanosis, pallor)5. Hardware failure (EKG, BP)6. Subject request7. Sustained ventricular tachycardia8. ST elevation >1 mm (not V1or aVR)SVT = supraventricular tachycardia (rate > 120 )VPC = ventricular premature contractionVT = sustained ventricular tachycardia (palpitations, weakness, dizzinesssyncope, circulatory collapse.)VF = ventricular fibrillationACSM Relative indications for Terminating a Test (Box 5-2, pg 106)1. SBP > 10 mmHg from baseline with work rate but no ischemia2. ST or QRS changes, > 2mm horizontal or down-sloping ST segment depression or marked axis shift3. Arrhythmias other than sustained ventricular tachycardia, including multi-focal PVCs, Supra-ventricular tachycardia, heart block, or bradyarrhythmias5 Relative indications , Fatigue, shortness of breathe, wheezing, leg cramps, claudication5.

6 BBB or intraventricular conduction delay that cannot be distinguished from ventricular tachycardia6. Increasing chest pain7. SBP > 250 mm Hg and/or DBP > 115 mm HgCase StudieszLessons learned don t test a person with unstable angina (most important contra -indication) don t test a person with known, severe, left coronary artery disease don t continue a test if bp falls with increase in work loadConclusionszIs stress testing safe? When yes When nozWhat can you do to make stress testing as safe as possible? When not to test? When to stop?