The Framingham Study reported that the incidence of deaths from cardiovascular causes was 43% in men with atrial fibrillation and 21% in men with sinus rhythm (risk ratio = 2.0), and 41% in women with atrial fibrillation and 15% in women with sinus rhythm (risk ratio = 2.7). 1 At 34-month mean follow-up of 118 patients with global T-wave inversion, Walder and Spodick 6 demonstrated that the mortality rate was 58% in 12 patients with atrial fibrillation detected by electrocardiograms, and 35% in 106 patients with sinus rhythm (p = 0.005). Data from this study show that atrial fibrillation is an independent predictor of new coronary events in elderly patients with heart disease. The time to onset of new coronary events was also significantly shorter in patients with atrial fibrillation than in patients with sinus rhythm or supraventricular tachycardia. After controlling for other prognostic variables, patients with atrial fibrillation and heart disease had a 2.2 times higher probability of developing new coronary events than those with heart disease without atrial fibrillation.