Does electrical stimulation of the carotid-sinus nerves improve symptoms and exercise capacity in patients with medically refractory angina pectoris?
Implanted carotid-sinus nerve stimulators can provide symptomatic relief and improve exercise capacity in patients with refractory angina, primarily by reducing arterial pressure and myocardial oxygen demand.
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.
Epstein et al. (Thu,) studied this question.