CHANGES IN QRS AMPLITUDE TO LEFT VENTRICULAFMASS RELATION IN RATS TREATED BYANTIHYPERTENSIVE DRUGS

摘要

The aim of the study was to analyze the relationship between QRS amplitude and left ventricular mass in spontaneously hypertensive rats treated by enalapril and lacidipine. Four groups of male experimental animals were studied at the age of 20 weeks: (1) Control Wistar-Kyoto rats (WKY); (2) spontaneously hypertensive rats (SHR); (3) SHR treated by enalapril (10 mg/kg/day) for eight weeks; and (4) SHR treated by lacidipine (3 mg/kg/day in two doses) for eight weeks. Systolic blood pressure (SBP) and Frank orthogonal electrocardiograms were recorded. Left ventricular mass (LVM) was measured after the rats were sacrificed. The specific potential of myocardium (SP) was calculated as a ratio of the maximum spatial QRS vector magnitude (QRSmax) and LVM. In both enalapril and lacidipine treated groups, significantly lower values of SBP and LVM/BW were observed as compared to the SHR group. The QRS values did not change significantly (0.45+0.1 mV and 4.9+0.1 mV, resp. vs 0.47+0.1 mV). The SP values were higher in both treated groups as compared to untreated SHR, in the case of enalapril significantly (0.6+0.1 mV/g and 0.72+0.1 mV/g, resp. vs 0.58+0.1 mV/g). The SP was a useful tool to study the effect of antihypertensive drugs on electrical characteristics of myocardium.