 - Cardiac disease: congestive heart failure class II NYHA; patients must not have unstable angina anginal symptoms at rest or new onset angina began within the last 3 months or myocardial infarction within the past 6 months; significant history of uncontrolled cardiac disease; i.e., uncontrolled hypertension defined as defined as systolic blood pressure 150 mmHg or diastolic pressure 90 mmHg, despite optimal medical management, uncontrolled congestive heart failure, and cardiomyopathy with decreased ejection fraction will also be excluded from study; cardiac ventricular arrhythmias requiring anti-arrhythmic therapy will also be excluded from study 