It is difficult today to appreciate the extent to which Carl Wiggers dominated cardiovascular physiology during the middle of the 20th century. The impact of his work far exceeded his individual discoveries, which were many, but instead reflected the totality of his research, most of which was carried out in the Department of Physiology at Western Reserve University in Cleveland Ohio. Wiggers provided a lucid description of the cardiac cycle, often referred to as the “Wiggers' Diagram,” that related changing pressures in the heart and great vessels, ventricular volume, heart sounds, and the electrocardiogram. He was a pioneer in cardiac electrophysiology who described impulse propagation through the ventricles, mechanisms responsible for premature systoles, the vulnerable period of the cardiac cycle when the ventricles are most susceptible to fibrillation, and the role of cardiac compression and electrical countershock in reversing ventricular fibrillation...