Study images should be reviewed by a trained cardiologist with knowledge about exercise physiology and the expected hemodynamic changes with exercise. Cardiac output increases with exercise, because of an increase in both HR and stroke volume, and this in turn increases transvalvular and transpulmonary flow (and pressure) in normal individuals. Differentiating normal and abnormal response to exercise can thus be challenging. Additionally, when exercise is performed supine, there may be a lower HR response and a greater blood pressure response to exercise because of increased preload relative to upright exercise.
When evaluating bicycle stress echo data, it is also important to interpret the results in the context of the patient’s overall functional capacity. For example, an increase in left ventricular outflow velocity to 4 m/sec may be functionally significant in a patient with hypertrophic cardiomyopathy if it occurs very early in exercise, but it may be less clinically important if it occurs only at above-predicted workloads. In all cases, functional capacity should be determined by comparing with normal reference standards for age and sex.