The diagnostic significance of the correlation between the effectiveness of subendocardial perfusion and the energy output compatible with the coronary reserve.

The effectivity of subendocardial perfusion was investigated in 266 probands aged 40-68 years (112 patients with ischaemic heart disease, 116 patients with essential hypertension, and 38 practically healthy persons) by a noninvasive technique - the myocardial vitality index (MVI) or the quotient of the diastolic and systolic tension-time indexes (DTTI/STTI). The close and statistically significant correlation was found between the MVI, findings of selective coronarography, and total physical performance (exercise tolerance threshold) in per cent of the maximal oxygen consumption (MOC) adequate to the given subject's age, sex, and body mass. Attention is drawn to the diagnostic potential of the novel mode of a rapid assessment of the expected exercise tolerance threshold in per cent of the admissible MOC, determined by the magnitude of the coronary reserved of energy output (in kcal/min or kJ/min), and to the possibilities of predicting the maximal admissible heart rate during exercise on the basis of the myocardial oxygen supply/consumption quotient during a state of relative muscular rest, reflecting the MVI.