Attenuation of Exercise-induced R Wave Increase after Diltiazem in Effort Angina Pectoris

Abstract

Body surface mapping was used to study the effects of diltiazem on exercise-induced QRS amplitude changes in 7 patients with stable effort angina pectoris. Body surface areas showing R or S amplitude changes (>0.2mV) after treadmill exercise were calculated. After the administration of 90mg of diltiazem, the R increased area was significantly smaller than that without diltiazem (p<0.02), although the same workload was performed. It was suggested that diltiazem diminished the exercise-induced myocardial ischemia and this improvement of ischemia resulted in the reduction of the R increased area after exercise.