Although amiodarone was effective in suppressing ventricular arrhythmias and improving ventricular function, it did not reduce the incidence of sudden death or prolong survival among patients with heart failure, except for a trend toward reduced mortality among those with nonischemic cardiomyopathy.

Amiodarone and sotalol are equally efficacious in converting atrial fibrillation to sinus rhythm. Amiodarone is superior for maintaining sinus rhythm, but both drugs have similar efficacy in patients with ischemic heart disease. Sustained sinus rhythm is associated with an improved quality of life and improved exercise performance.

Dofetilide, a new class III antiarrhythmic agent, is moderately effective in cardioverting AF or AFl to SR and significantly effective in maintaining SR for 1 year. In-hospital initiation and dosage adjustment based on QTc and Cl(Cr) are necessary to minimize a small but nonnegligible proarrhythmic risk.

Background-Exercise capacity is inversely related to mortality risk in healthy individuals and those with cardiovascular diseases. This evidence is based largely on white populations, with little information available for blacks. Methods and Results-We assessed the association between exercise capacity and mortality in black (nϭ6749; age, 58Ϯ11 years) and white (nϭ8911; age, 60Ϯ11 years) male veterans with and without cardiovascular disease who successfully completed a treadmill exercise test at the Veterans Affairs Medical Centers in Washington, DC, and Palo Alto, Calif. Fitness categories were based on peak metabolic equivalents (METs) achieved. Subjects were followed up for all-cause mortality for 7.5Ϯ5.3 years. Among clinical and exercise test variables, exercise capacity was the strongest predictor of risk for mortality. The adjusted risk was reduced by 13% for every 1-MET increase in exercise capacity (hazard ratio, 0.87; 95% confidence interval, 0.86 to 0.88; PϽ0.001). Compared with those who achieved Ͻ5 METs, the mortality risk was Ϸ50% lower for those with an exercise capacity of 7.1 to 10 METs (hazard ratio, 0.51; 95% confidence interval, 0.47 to 0.56; PϽ0.001) and 70% lower for those achieving Ͼ10 METs (hazard ratio, 0.31; 95% confidence interval, 0.26 to 0.36; PϽ0.001). The findings were similar for those with and without cardiovascular disease and for both races. Conclusions-Exercise capacity is a strong predictor of all-cause mortality in blacks and whites. The relationship was inverse and graded, with a similar impact on mortality outcomes for both blacks and whites. (Circulation. 2008;117: 614-622.)