Download Cardiac stress testing

Karam Paul MS, MD, MBA, FACC Community Heart and Vascular

►Know why to undertake a stress test ►Know who should have one ►Know how it is performed ►Understand the limitations ►Understand which to choose ►Know what to do with the result

Why do a stress test?

►Elicit abnormalities not present at rest ►Estimate functional capacity ►Estimate prognosis ►Likelihood of coronary artery disease ►Extent of coronary artery disease ►Effect of treatment

Who should have one?

►Bayes’ Theorem ►Consider the ‘pre-test risk’

►Sensitivity & specificity of the test ►Post-test probability of CAD

►Diagnostic power of EST is maximal when the pre-test probability is intermediate.

►Pre-existing coronary artery disease ►Diabetes

►Hypertension ►Smoking history

►Family history ►Renal disease

Pre-existing coronary artery disease ►Diabetes ►Hypertension ►Hyperlipidemia ►Smoking history ►Family history ►Renal disease

►Pre-existing coronary artery disease ►Diabetes ►Hypertension ►Hyperlipidemia ►Smoking history ►Family history ►Renal disease

How is it done?

►ECG ►Exercise capacity (METS – metabolic equivalent)

►Symptoms ►Blood pressure

►Heart rate response & recovery

1mm planar ST depression

3 consecutive beats

► The normal and rapid upsloping ST segment responses are normal responses to exercise. ► Minor ST depression can occur occasionally at submaximal workloads in patients with coronary disease. ► The slow upsloping ST segment pattern often demonstrates an ischemic response in patients with known coronary disease or those with a high pretest clinical risk of coronary disease. ► Downsloping ST segment depression represents a severe ischemic response. ► ST segment elevation in an infarct territory (Q wave lead) indicates a severe wall motion abnormality and, in most cases, is not considered an ischemic response. (From Chaitman BR: Exercise electrocardiographic stress testing. In Beller GA [ed]: Chronic Ischemic Heart Disease. In Braunwald E [series ed]: Atlas of Heart Diseases. Vol 5. Chronic Ischemic Heart Disease. Philadelphia, Current Medicine, 1995, pp 2.1-2.30

► Influenced by: Body position Respiration Hyperventilation Drug Rx Myocardial ischemia Necrosis ► Pseudonormalisation: Usually non-diagnostic Consider ancillary imaging

►Peak HR > 85% of maximal predicted for age

►HR recovery >12 bpm (erect) ►HR recovery >18 bpm (supine)

Parameters associated with adverse prognosis or multivessel disease ► Duration of symptom-limiting exercise