Abstract
This study was conducted to investigate the differences between ventricular arrhythmias (VA) of spontaneously hypertensive rat (SHR) and normotensive Wister rat (WR) after coronary artery ligation (CL) . Twenty SHR and 21 WR were used. CL was performed and electrocardiograms (ECG) were recorded for 20 min without anesthesia. Infarct was 39 % in the left ventricle of SHR and 33 % in WR. VA appeared immediately after CL, disappeared after 1 to 3 min, and reappeared after 3 min. The VA appeared significantly earlier in SHR, and the frequency within 1 min was significantly greater in SHR than in WR. Within 1 min, the average PVC was 36 in SHR, and 13 in WR (p<0.01) ; VT was 4 in SHR, and 1 in WR (p<0.01) . VF within 1 min was seen only in SHR. R wave amplitude in lead I increased to 265 % of the control in SHR, and to 228 % in W R at 15 sec, and these two increases were significantly different. ST elevation was significantly higher in SHR throughout the experiment, except at 2 mm. The incidence of ST alternans was 75 % in SHR, and 24 % in WR (p<0.05), In summary, VA after CL appeared significantly earlier in SHR than in WR, and their incidence within 1 min was significantly more frequent in SHR. The ECG changes during CL were more severe in SHR than in WR.
