In 1952 Paul M. Zoll, M.D was Chief of the Cardiac Clinic at Beth Israel Hospital. He demonstrated that external electrical stimulation of a patient’s chest during cardiac arrest could produce an effective heartbeat.

In 1956he is the first physician to successfully use external defibrillation to regulate heart rhythms in patients. This discovery contributes significantly to the decrease in heart disease mortality.

With technical collaborators, Dr. Zoll develops a way to display the heart’s cardiac electrical activity on an oscilloscopic screen. This includes registering each heartbeat with an audible signal, and sounding an alarm at the onset of cardiac arrest. These developments lead to cardiac monitors and other programs found in modern cardiac care units.

In 1960He discovers that external electrical countershock is effective in terminating supraventricular tachycardia and ventricular tachycardia.

In 2001 the ZOLL AED Plus® was designed in cooperation with the Burlington, Mass. Police Department and hundreds of other first responders and EMS agencies.