Cardiopulmonary baroreceptor reflex in patients with hypertrophic cardiomyopathy with diastolic left ventricular dysfunction

Cardiopulmonary baroreceptor reflex was tested in 42 patients with hypertrophic cardiomyopathy. For this purpose directly measured right atrial pressure was gradually decreased by local decompression of lower extremities. Forearm regional blood flow was assessed by venous occlusion plethysmography. Analysis of cardiac cycle phases and echocardiography were used for determination of functional and morphological parameters of the left ventricle. The tone of autonomic (vegetative) nervous system was also evaluated. Direction of changes of cardiopulmonary baroreceptor reflex was related to character of disturbances of left ventricular diastolic function. Changes of passive component of diastolic function (decrease of left ventricular cavity) were associated with augmented cardiopulmonary baroreceptor reflex while changes of its active component (prolongation of isovolumic relaxation phase) - with displacement of vegetative tone towards sympathicotonia.