Left ventricular filling pressures can be estimated reliably by combining mitral inflow early diastolic velocity (E) and annulus velocity (E'). An increased E/E' ratio reflects elevated filling pressures and may be useful in assessing an abnormal increase in filling pressures for patients with diastolic dysfunction. The purpose of this study was to evaluate the feasibility of supine bicycle exercise Doppler echocardiography for assessing left ventricular diastolic pressure during exercise. Mitral inflow and septal mitral annulus velocities were measured at rest and during supine bicycle exercise (25-W 3-minute increments) in 45 patients (19 men; mean age, 59 years) referred for evaluation of exertional dyspnea. None had echocardiographic or electrocardiographic evidence of myocardial ischemia with exercise. Patients were classified according to E/E' ratio at rest: 26 had E/E' < or = 10 at rest (group 1) and 19 had E/E' > 10 (group 2). For group 1, 17 had no increase in E/E' during exercise (group 1A) and 9 did (group 1B). For group 2, E/E' did not increase during exercise. Despite different responses of E/E', there was no significant difference in changes of mitral inflow indices (E, A, E/A, deceleration time) between groups. Although the percentage of dyspnea as a primary reason for stopping exercise was similar for the groups, exercise duration was significantly shorter for groups 1B (7.2 +/- 2.5 minutes) and 2 (7.1 +/- 3.3 minutes) than in group 1A (10.4 +/- 3.7 minutes, P = .0129). Diastolic stress echocardiography using a supine bicycle is technically feasible for demonstrating changes in E/E' (filling pressure) with exercise. Our preliminary results suggest the hemodynamic consequences of exercise-induced increase in diastolic filling pressure can be demonstrated noninvasively with exercise Doppler echocardiography.