Bicycle ergometry has a significant advantage in that echocardiographic imaging can be performed at each stage of exercise. Apical imaging is continued actively throughout most of the exercise. For supine ergometry, most laboratories configure the studies to include 4 views and 4 stages. Usual images included are 4 views of a predetermined cardiac site on a single quad screen at rest, low stress, peak stress, and either recovery or intermediate stress. Upright bicycle ergometry provides images with quality between that of the treadmill and supine bicycle because parasternal views are frequently not possible because of the upright position.
Analysis is based on regional wall motion abnormalities.
The ventricle is divided into a 16-segment model as recommended by the American Society of Echocardiography. Then, each of the 16 segments is graded with respect to wall motion as normal, hypokinetic, akinetic, dyskinetic, or aneurysmal. Comparison of wall motion scores at rest and varying levels of stress provides a quantitative measure of the severity of ischemia. 11 months by Marwick et al showed that positive test results for ischemia are highly predictive of coronary events. This modality identifies the presence and amount of coronary artery calcium, which has been shown to be related to atherosclerosis.