Sinus node deceleration during exercise as a marker of significant narrowing of the right coronary artery

The hallmark of exercise-induced ischemia is ST-segment depression on the exercise electrocardiogram. Other indicators of exercise-induced ischemia include ST-segment elevation, U-wave inversion, chronotropic incompetence, hypotension and ventricular ectopy.¹ Sinus node deceleration, defined as an initial increase and subsequent decrease in heart rate with continued exercise at the same or higher work load, has not been described as a marker of coronary artery disease. We previously reported a patient with sinus node deceleration and subsequent resolution on repeat exercise testing after angioplasty of a right coronary artery stenosis.² In this study, we report an additional 7 patients with sinus node deceleration, all of whom had angiographically confirmed disease of the right coronary artery.