Alterations in the Circulatory Response to Exercise Following a Meal and Their Relationship to Postprandial Angina Pectoris

Abstract

In order to study the mechanisms responsible for the more rapid precipitation of angina in the postprandial state, we evaluated the circulatory response to upright bicycle exercise in 12 patients with angina before and after a meal. Eleven of 12 subjects developed angina sooner after eating (average 1.3 min, P < 0.001). Comparison of circulatory responses revealed that a given amount of postprandial exercise resulted in faster heart rate (12 beats/min, P < 0.001) and greater blood pressure (6 mm Hg, P < 0.05). The product of blood pressure and heart rate (an index of myocardial oxygen demand) at onset of angina during postprandial exercise was the same as corresponding preprandial values. Our results suggest that the accelerated development of angina during exercise after meals is primarily due to a more rapid rise in heart rate and blood pressure, factors tending to augment myocardial oxygen requirements, rather than the result of a deleterious effect of digestion and absorption on myocardial oxygen delivery.