THE SIGNIFICANCE OF RIGHT-VENTRICULAR ISCHEMIA IN REFLEX BRADYCARDIA IN HUMANS

Heart rates (HR) were measured before (control HR) and after (ischemic HR) balloon inflation during percutaneous transluminal coronary angio plasty in 96 patients with effort angina pectoris. The delta HR, defin ed as (ischemic HR-control HR), in the right coronary artery occlusion was significantly smaller than that in the left anterior descending a rtery or left circumflex artery occlusion. Among right coronary artery occlusions the delta HR in segment 1 occlusion was significantly smal ler than that in segment 2 or segment 3 occlusion. It is suggested tha t the ischemia of the right ventricle plays an important role in produ cing a reflex bradycardic response in humans.