THE EFFECTS OF SYMPATHECTOMY ON THE ELECTROCARDIOGRAM AND EFFORT TOLERANCE IN ANGINA PECTORIS

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Abstract
A study has been made of the effect of upper thoracic sympathectomy in 8 patients with severe angina pectoris. Effort tolerance was measured on a treadmill, and electrocardiograms were recorded during the exercise. Tests were repeated on each patient before operation until consistent results were obtained; similar tests were performed after surgery at intervals, over a follow-up period ranging from 3 to 14 months. Effort tolerance was increased two- to threefold in 6 of the 8 patients, and there was a corresponding delay in or abolition of the ischemic abnormalities in the electrocardiogram during effort. When changes did occur comparable to those accompanying pain before sympathectomy, the patients experienced discomfort and stopped walking. Six patients were also tested after treatment with pronethalol, a [beta]-sympathetic blocking drug. All were able to walk further than they could after a placebo, and in 3 of them the increase in effort tolerance was 50% or more. The objective improvement after sympathetic ablation is due principally to the reduction in tachycardia and the oxygen-wasting increase in contractility, which are the normal responses to excitement and exercise.