Direct Arterial Pressure and the Electrocardiogram in Unrestricted Patients with Angina Pectoris

Direct arterial pressure and electrocardiogram have been recorded over a 24 hr period in 8 males with angina pectoris who were completely unrestricted throughout the study. Twenty-five separate episodes of angina occurred, precipitated by exertion, eating, smoking, and anxiety, in addition to 2 spontaneous attacks and 2 episodes of nocturnal angina. All but 2 angina episodes were accompanied by a rise in both arterial pressure and heart rate. In the cases of spontaneous and nocturnal angina these pressure and rate changes began 10-15 min before the pain. In exertional angina these changes were related to the degree of activity involved, while in other instances there was a brief surge of pressure and rate occurring at the time of onset of pain. In each patient pain tended to occur at approximately the same level of pressure-rate product. ST-segment changes in the electrocardiogram showed no consistent pattern, occurring before or after the onset of pain, while in some episodes there was no significant change. A limited number of observations were made on the effect of glyceryl trinitrate and β-adrenergic receptor blocking drugs.