What is an Exercise Stress Echocardiogram?
An exercise stress echocardiogram is a diagnostic cardiac test that combines physical exercise (typically treadmill or bicycle) with ultrasound imaging of the heart to detect coronary artery disease by visualizing new or worsening wall motion abnormalities that indicate myocardial ischemia. 1
How the Test Works
Exercise stress echocardiography uses dynamic forms of exercise to stress the heart while acquiring echocardiographic images of left ventricular function. 1 The test evaluates:
- Segmental and global left ventricular dysfunction as manifestations of ischemia 1
- Wall motion abnormalities including hypokinesia or akinesia that indicate ischemia or necrosis 2
- Changes in left ventricular end-systolic size during exercise 1
Primary Clinical Applications
The test is predominantly used in symptomatic patients to assist in diagnosis of obstructive coronary artery disease, not for risk assessment in asymptomatic individuals. 1 Specific indications include:
- Chest pain in patients with intermediate probability of coronary artery disease 3
- Patients unable to perform physical exercise who require diagnostic evaluation 3
- Non-diagnostic resting or exercise electrocardiography 3
- Symptomatic patients after revascularization or those qualified for revascularization for functional assessment of coronary artery stenosis 3
When Exercise Stress Echo is Particularly Useful
The test is specifically indicated for patients with abnormal resting ECG findings that make standard exercise ECG uninterpretable, including:
- Left bundle-branch block 1
- Electronically paced rhythm 1
- Left ventricular hypertrophy 1
- Patients taking digoxin 1
Technical Requirements
Two operators should perform the test: a physician experienced in stress echocardiography (at least 100 tests completed under supervision) and a trained nurse or another doctor. 3 The laboratory must feature:
- A defibrillator and resuscitation kit with pharmaceuticals 3
- An intubation kit and AMBU bag 3
- Skilled acquisition and interpretation of images according to best practices 1
Prognostic Value
Normal exercise echocardiography indicates a very low cardiovascular event rate of less than 1% per year. 2 Conversely:
- A positive stress echocardiogram is associated with a threefold increased incidence of any cardiac event and fourfold increased incidence of myocardial infarction within 12 months compared to a negative test 4
- Patients with normal exercise echocardiograms are at very low risk for subsequent cardiac events 1
Important Caveats
Exercise stress echocardiography is NOT indicated for cardiovascular risk assessment in low- or intermediate-risk asymptomatic adults. 1 This Class III recommendation reflects lack of population evidence for risk assessment purposes in asymptomatic individuals. 1
The diagnostic performance is highly dependent on availability of skilled acquisition and interpretation, and should only be performed according to best practices. 1 Major adverse outcomes are uncommon but can occur, with complications most common during dobutamine stress echocardiography. 5