1. From the Department of Internal Medicine, Des Moines General Hospital, Des Moines, Iowa
2. From the Detroit Osteopathic Hospital/BiCounty Community Hospital, Detroit, Michigan
3. From the Section of Cardiovascular Surgery, Department of Surgery, Des Moines General Hospital, Des Moines, Iowa
4. Department of General Practice, Des Moines General Hospital, Des Moines, Iowa
5. Department of Internal Medicine, Des Moines General Hospital, Des Moines, Iowa