Stress Echocardiography in Regurgitant Valve Disease
Because of its wide availability, low cost, versatility, and clinical use, stress echocardiography has become increasingly recognized as a valuable tool in the assessment of patients with regurgitant valvular heart disease. Exercise testing is favored compared with pharmacological stress testing for risk stratification in asymptomatic patients and can identify what might otherwise be considered as a moderate valve disease. It has been shown to provide insights into exertional symptoms disproportionate to resting hemodynamics in these patients and to facilitate individual risk stratification. Aggravation of valvular regurgitation severity, exercise-induced pulmonary hypertension (PHT), impaired left ventricular (LV) contractile reserve, inducible ischemia, dynamic LV dyssynchrony, and altered exercise capacity, together with the development of symptoms during exercise echocardiography, provide the clinician with straightforward prognostic information, therefore enabling a more accurate definition of the optimal timing of intervention in patients with valvular regurgitation.1,2 In contrast, dobutamine stress echocardiography has little value in cases of valvular regurgitation. Dobutamine infusion is almost systematically associated with a decrease in the severity of regurgitation; however, it might be of interest in the detection of LV contractile reserve and inducible ischemia.
Exercise Echocardiography and Protocols
The most common form of exercise used in conjunction with echocardiography is immediate postexercise imaging on a treadmill or upright bicycle ergometer. However, semisupine exercise testing on an appropriate tilted table allows continuous echocardiographic monitoring, which represents an advantageous tool for quantifying changes in valvular regurgitation severity, LV function, and pulmonary pressure (Table). This exercise stress echocardiography modality (ie, per-exercise echocardiography) is the most used in Europe, and we strongly suggest this approach in the setting of valvular heart disease to detect evanescent changes. A symptom-limited graded exercise test is recommended, and ≥80% of the age-predicted upper heart rate should be reached in the absence of symptoms. The test is adapted to the clinical conditions …