Joshua Cooper, MD, FACC, FHRS, Director of Cardiac Electrophysiology at Temple University Hospital and Professor of Medicine at the Lewis Katz School of Medicine at Temple University, offered insight to the Philadelphia Inquirer about Pennsylvania Lt. Gov. John Fetterman, who had a stroke and a pacemaker/defibrillator implanted. The stroke was caused by a blood clot due to his heart being in atrial fibrillation (Afib). Dr. Cooper has not treated Lt. Gov. Fetterman.