1952

Paul Zoll builds and successfully employs first external pacemaker, a box worn around the neck with leads attached to chest skin, but it could not be worn for more than seven days, causing skin burns around the electrodes and painful contraction of skeletal chest muscles, and frequently required sedation owing to the degree of discomfort. In early 1953, he announced effectiveness of pacing in managing Stokes-Adam Syndrome (associated with total heart block since late 19th c.), and this attracted both professional public interests. In 1946, Leatham and colleagues developed an external transcutaneous pacemaker that incorporated automatic onset and termination of stimulation (Furman; Jeffrey, ch 2). Zoll’s most important insight at this stage of the field was his recognition that he should pace the ventricle, not the atrium. . . . Zoll also recognized that pacemaker stimuli might be able to restore a normal heart rhythm in circumstances other than Stokes-Adams attacks. . . . After 1952, Zoll developed an external AC defibrillator and a cardiac monitor that would enable the attending physician to diagnose instantly the onset and nature of a dangerous arrhythmia. Together with the external pacemaker, these machines provided the initial technological basis for the cardiac intensive care units that mushroomed in U.S. hospitals during the 1960s: (Jeffrey, loc 244-246).