Congestive heart failure (CHF) represents a major health care concern in the United States. Currently, risk stratification of sudden cardiac death and the need for implantable cardioverter-defibrillator (ICD) placement are essentially dependent upon assessment of left ventricular ejection fraction (LVEF). Nevertheless, the predictive value of LVEF is suboptimal, alternative testing for risk assessment for the development of sudden cardiac death in the heart failure population is desirable.