Seventeen hypertensive patients with EKG evidence of left ventricular hypertrophy and subendocardial ischemia were studied. The following tests were performed: cine-ventriculography, coronary arteriography, ejection fraction, ventricular pressures, left ventricular mass, EKG stress test and atrial stimulation. In 10 cases cardiac scintigraphy with intracoronary injection of albumin-macro-aggregates marked with TC 99m, was obtained. EKG stress and atrial stimulation tests were positive in all cases, with ST depression greater than 1mm, or accentuation of previous ST depression. 83.7% of the patients had permeable coronary arteries, with "corkscrew' tortuosity. Left ventricular mass was increased in all cases (119 +/- 28.5% m2 s/c). Ejection fraction (74.2 +/- 8.1), and left ventricular diastolic pressures were normal. Cardiac scintigraphy showed uniform distribution of the radioisotope in the right ventricle and poor concentration with better dispersion and distribution in the left ventricle. It is concluded that subendocardial ischemia in these subjects is not produced by obstruction of the main coronary trunks and is associated to a significant increment of left ventricular mass which possibly produce a poor coronary reserve, and a potentially high risk condition.