REGIONAL DIASTOLIC CORONARY BLOOD-FLOW DURING DIASTOLIC VENTRICULAR HYPERTENSION

Summary: The effect of diastolic ventricular hypertension on regional diastolic coronary flow was measured with radioactive microspheres in the canine heart paced at a constant rate and perfused only during diastole with a constant coronary perfusion pressure. Diastolic ventricular hypertension produced an homogenous increase of diastolic flow across the left ventricular wall when the metabolic coronary autoregulation was intact, but produced a decrease in subendocardial diastolic flow when the autoregulation was abolished. These results suggest that diastolic ventricular hypertension produces a higher subendocardial than subepicardial mechanical resistance to diastolic coronary flow.