Regression of hypertrophy: Beneficial or harmful: Effect of stress

Abstract

Whether regression of cardiac hypertrophy is beneficial or harmful is still an open question, especially when the heart is exposed to a sudden stress. To evaluate the tolerance of the heart to stress after regression, we treated SHR with captopril (CAP), propranolol (PRO) and hydralazine (HYD), and determined their collagen and transcript levels and correlate with the functional consequences. The systolic function has been evaluated by dobutamine stress echocardiography (DSE). The effect of stress with dobutamine was assessed and correlated with the molecular changes. CAP treatment caused regression of hypertrophy associated with the reduction in collagen (13 mgig vs 7.3 mgigm, p O.O5). HYD and PRO showed no regression of hypertrophy and no change in reserve after dobutamine stress. Our data showed that regression of LVH using CAP was associated with a reduction of baseline stroke volume, but normalization of dynamic cardiac response to stress, whereas HYD and PRO failed to cause a similar response. Quality and quantity of collagen appear to be an important factor. It is important to note that CAP would be a better drug in treating hypertensive hypertrophq to obtain an improved cardiac functional reserve.