Stroke-prone SHR (SHRSP) as models for clinical and epidemiological studies on hypertension-related cardiac diseases in humans.

Spontaneously hypertensive rats (SHR) and stroke-prone SHR (SHRSP) were vectorcardiographically and pathologically studied for myocardial lesions with left ventricular hypertrophy, and findings were compared with those in normotensive Wistar-Kyoto rats (WK). Characteristic vectorcardiogram (VCG) in adult SHR was left superior (posterior) deviation of major QRS portion usually with ST-T changes, which corresponded to the pathological findings such as increased weight of the heart and the left ventricle. In old SHRSP, VCG showed deformity and deviation of QRS loop with prolonged P and QRS durations, and ST-T changes which corresponded to the pathological findings of myocardial degeneration or fibrosis with aggravated left ventricular hypertrophy. Such myocardial lesions were vectorcardiographically followed up in the ageing process and compared with findings in cases of induced, acute myocardial infarction. Vascular or tissue lesions of the brain, the kidney and the heart were clarified to be organ specific and to be related. Vector- or electrocardiogram are parameters for predicting cerebral stroke and/or ischemic heart diseases in humans. Primary prevention and appropriate therapy should be concomitantly considered.