What will a stress echocardiogram (echo) show that a normal echocardiogram (echo) will not?

From the Guidelines

A stress echocardiogram will show wall motion abnormalities, ischemia, and stress-induced valve dysfunction that may not be apparent on a normal echocardiogram. This is because a stress echo evaluates the heart's function under conditions of physiological or pharmacological stress, allowing for the detection of abnormalities that only occur when the heart is working harder 1. The images obtained during a stress echo permit matching symptoms with cardiac involvement, unmasking structural or functional abnormalities that may be occult in the resting state 1.

Some of the key differences between a stress echo and a normal echo include:

• The ability to detect coronary artery disease by showing areas of the heart muscle that don't contract properly during stress 1
• The identification of ischemia, wall motion abnormalities, and stress-induced valve dysfunction 1
• The evaluation of the heart's functional capacity under exertion 1
• The comparison of heart function at rest versus during stress, potentially revealing blockages in coronary arteries that limit blood flow only when the heart's oxygen demand increases 1

During a stress echo, images are taken before and immediately after exercise or after administration of medications like dobutamine that simulate exercise effects 1. This allows cardiologists to assess the effectiveness of treatments for heart disease, evaluate heart valve function during exertion, and determine exercise capacity 1.

It's worth noting that the diagnostic accuracy of stress echocardiography has been studied extensively, with sensitivity ranging from 70% to 85% for exercise and 85% to 90% for pharmacological stress echocardiography 1. The use of intravenous ultrasound contrast agents can improve endocardial border delineation and result in improved diagnostic accuracy 1.

From the Research

Stress Echocardiography vs Normal Echocardiography

A stress echocardiography (stress echo) will show several things that a normal echo will not, including:

• Myocardial contractility and cardiac ischemia in response to various stimuli, such as physical exercise, pharmacological agents, or pacing stress 2
• Valvular flow and left ventricular function under stress, which can help diagnose and assess coronary heart disease and valvular heart disease 2, 3
• Regional wall motion abnormalities (RWMA) that may indicate coronary artery disease (CAD), especially in patients with left ventricular dysfunction and a normal-sized or dilated left ventricle 4
• Segmental wall motion abnormalities, which can be a common finding and good prognostic sign in patients with dilated cardiomyopathy 5
• The effects of coronary atherosclerosis on left ventricular function and chamber dilatation in patients with aortic stenosis 6

Key Differences

The key differences between stress echocardiography and normal echocardiography are:

• The use of stressors to elicit myocardial contractility and provoke cardiac ischemia
• The ability to assess valvular flow and left ventricular function under stress
• The detection of RWMA and segmental wall motion abnormalities, which can indicate CAD or other cardiac conditions
• The evaluation of coronary atherosclerosis and its effects on left ventricular function and chamber dilatation

Clinical Applications

Stress echocardiography has several clinical applications, including:

• Diagnosis and assessment of coronary heart disease and valvular heart disease
• Evaluation of myocardial viability before potential revascularization
• Assessment of coronary flow reserve
• Functional assessment of coronary artery stenosis in symptomatic patients after revascularization or patients qualified for revascularization
• Detection of CAD in patients with intermediate probability of coronary artery disease, inability to perform physical exercise, and non-diagnostic resting or exercise electrocardiography 2, 3