Influence of prosthesis size and left ventricular mass on left ventriculardiastolic reserve in patients with aortic valve prostheses

Background and aim of the study: The study aim was to determine the influen ce of valve size and left ventricular (M mass on long-term LV diastolic res erve in patients subjected to aortic valve replacement for stenosis. Methods: Seventy-four patients (33 women, 41 men; mean age 64 years) after aortic valve replacement with 40 pericardial bioprostheses and 34 bileaflet mechanical prostheses were studied. All valves were of nominal size 19, 21 or 23 mm. The patients were studied by Doppler echocardiography, at rest a nd during peak effort, between 12 and 47 months after valve replacement. Results: All patients achieved significantly increased heart rate, blood pr essure and cardiac output in response to effort. Effort also significantly modified transvalvular pressure drops and valve areas. The mean diastolic r eserve was 29.3 ml, and mean stroke volume reserve 23.2 ml; in neither case were there any significant differences between valve types, or among valve sizes. Conclusion: At about one year after surgery, the diastolic reserve of patie nts subjected to aortic valve replacement on account of stenosis was consid erable, and independent of valve size. Despite the persistence of LV hypert rophy after valve replacement, LV diastolic function during effort was simi lar to that of the normal heart.