Cardiac performance in elderly hypertensive patients with left ventricular hypertrophy: responses to isometric exercise and beta-agonists.

To assess the cardiac functional reserve of elderly hypertensive patients with left ventricular hypertrophy (LVH) we studied cardiac function after isometric exercise and beta-adrenergic stimulation. Forty-five elderly hypertensive and 16 normotensive patients (NC group) were recruited for the study. The hypertensive patients were divided into two groups: those with LVH (n = 17) mass index (LV mass index greater than 130 g/m2; H1 group) and those without LVH (n = 28) (H2 group). Echocardiographic studies were performed before and after isometric exercise (handgrip) and isoproterenol (ISP) administration. We measured the LV mass index, fractional shortening (FS), isovolumic relaxation time (IRT), and the ratio of late and early diastolic transmitral flow velocity (A/E). The FS at rest in the H1 group was significantly higher than those in the H2 and NC groups. In the H1 group, the IRT was elongated and A/E was greater than in the NC group, which indicated the impaired diastolic function in the H1 group. After the HG stress, the FS in the H1 group significantly decreased whereas it did not change in the H2 or NC groups. The FS increased in all three groups after the infusion of ISP, although the increment of FS was smaller in the H1 group. In conclusion, (a) diastolic function was impaired whereas systolic function was supranormal at rest in the hypertrophied heart of the elderly hypertensive patients and (b) when exercise or pharmacological stress was loaded, the systolic function deteriorated, suggesting the impairment of cardiac reserve in those patients.