Exercise ECG Stress Testing for Internists

Salah Abusin, MD, MRCP, ABIM, ABIM (Card)Interventional Cardiologist

Dubuque, IA, USA

Stress Testing for Internists

• Principles & Purpose• Patient Preparation• Understanding the report• When NOT to do it – Contraindications• When to do it - Indications

Exercise ECG Stress Testing Principles

• Elicit cardiovascular & ECG abnormalities not present at rest and to determine the adequacy of cardiac function.

Exercise ECG Stress Testing Purpose

• estimate prognosis/determine functional capacity

• the likelihood and extent of coronary artery disease (CAD)

Procedure

1. Patient is connected to ECG monitor in treadmill 2. Check Baseline BP & 12 lead ECG3. Start treadmill4. Monitor patient for symptoms5. Check BP every 3 minutes6. Treadmill ECG machine records 12 lead ECG

periodically

When to stop

• Symptoms– Patient develops exercise limiting symptoms

• BP changes– Drop in BP or rise above 250/115

• ECG Changes– Significant arrhythmias– Pronounced ST changes from baseline

Patient Preparation

• Patients should refrain from ingesting food, alcohol, or caffeine or using tobacco products within 3 hours of testing.

• Patients should be rested for the assessment, avoiding significant exertion or exercise on the day of the assessment.

• Patients should wear clothing that allows freedom of movement, including walking or running shoes, and a loose-fitting shirt with short sleeves that buttons down the front. They should not wear restrictive undergarments during the test.

Understanding the ReportDuration of Exercise

• The most important prognostic information from the ECG Stress Test

Understanding the ReportTarget HR achieved?

• The target HR is measured as follows– 220 – Age

• HR with exercise should rise to > 85% of target HR to consider this sufficient exercise

• If the test is stopped early (in the absence of evidence of ischemia) before >85% of target HR is achieved then the test is considered inconclusive

Understanding the ReportDid the patient develop any

symptoms?

• Development of chest pain (with hemodynamic/ECG changes) suggested an increased likelihood of CAD

• Chest pain at low workload is considered a poor prognostic sign

Understanding the ReportBP changes during exercise

• SBP should rise with exercise• A drop in SBP with exercise is considered a

poor prognostic sign (indication to stop the test)

Understanding the ReportST segment changes with Exercise

• Development of significant ST depression during Exercise increases the likelihood of significant CAD

• Development of ST Elevation is considered a poor prognostic sign (indication to stop the test)

Understanding the ReportArrhythmias during Exercise

• Development of VT is considered a poor prognostic sign (indication to stop the test)

When not to do it?When it is not safe

• ACS – Acute Phase• Uncontrolled arrhythmia• Uncontrolled HF, uncontrolled HTN• Symptomatic Severe Ao stenosis• Acute PE• Suspected or known dissecting aneurysm• Active or suspected myocarditis, pericarditis, or endocarditis• Acute noncardiac disorder that may affect exercise

performance or be aggravated by exercise

When not to do it?When the ECG cannot be interpreted• ACS• Uncontrolled arrhythmia• Uncontrolled HF, uncontrolled HTN• Symptomatic Severe Ao stenosis• Acute PE• Suspected or known dissecting aneurysm• Active or suspected myocarditis, pericarditis, or endocarditis• Acute noncardiac disorder that may affect exercise

performance or be aggravated by exercise

Indications - Stable Angina

• Diagnosis of Obstructive CAD– Highest Yield in patients with intermediate

probability– When used in patients with low probability,

increases likelihood of false positive (especially in women)

• Risk Stratification in patients high probability of CAD

Indications – Unstable Angina

• Risk Stratification for Low risk Unstable Angina (negative troponin) after 8-12 hours

Indications – STEMI

• Before discharge for patients who underwent successful thrombolysis and did NOT undergo diagnostic coronary angiography

• Before discharge in patients who came with late presenting STEMI and did NOT undergo diagnostic coronary angiography

• Thanks