Treatment of Angina Pectoris by Electrical Stimulation of the Carotid-Sinus Nerves

Radiofrequency carotid-sinus nerve stimulators implanted for treatment of incapacitating angina pectoris, unrelieved by intensive medical management, produced appreciable symptomatic improvement in 13 of 17 patients: nearly all episodes of angina were terminated by activation of the stimulator, and prophylactic use increased intensity and duration of exercise that could be performed. After long-term use exercise capacity was increased in many patients even when the stimulator was not activated. Two had no benefit, and two died. Prophylactic use during exercise lowered mean arterial pressure an average of 18 mm of mercury (p less than 0.001) in 13 of the 15 survivors, but heart rate was reduced by an average of only 4 beats per minute. The other two showed no hemodynamic response. The principal physiologic factor in the relief of angina appears to be a decrease in arterial pressure, which reduces a major determinant of myocardial oxygen consumption and re-establishes the balance between myocardial oxygen demands and supply.