An Implantable, Synchronous Pacemaker for the Long-Term Correction of Complete Heart Block

Abstract

An implantable, synchronous cardiac pacemaker for long-term correction of complete heart block has been developed. It has been successfully used in dogs for periods up to eight months. The performance of the pacemaker during normal sinus rhythm and atrial arrhythmias is illustrated with electrocardiograms. After implantation of the pacemaker, the dogs have returned to completely normal activity and have tolerated all physical exercises well. [see figure in the PDF file]

Causes of death in patients with complete heart block and aritificial pacemakers.

“…The 1-year survival rate for untreated patients with chronic complete heart block is possibly 60 per cent (Friedberg, Donoso, and Stein, 1964;Johansson, 1966), but an accurate estimation is difficult to determine from the published reports (Siddons and Sowton, 1967). The 1-year survival rate for 108 patients paced at St. George's Hospital is 78 per cent, which is comparable to other centres (Chardack et al, 1965;Elmqvist and Senning, 1960;Nathan et al, 1963;Taylor, 1966;Zoll et al, 1961). In an attempt to find an explanation for this still relatively high mortality (22%), an analysis has been made of the clinical and pathological findings in all patients who came to necropsy following pacing in the past 4 years.…”

Electromagnetic Interference of Implantable Unipolar Cardiac Pacemakers by an Induction Oven

“…11 Especially after the demand mechanism of sensing cardiac electric pulses began to be incorporated in cardiac pacemakers, the cardiac pacemakers have been reported to be significantly influenced by electromagnetic fields. 12,13 The EMI is, therefore, considered to be caused by the sensing mechanism and the logic of pulse generation. Although the electrical potential produced by the excitation of cardiac muscles is detected as the electrical potential between the sensing electrodes of cardiac pacemakers, the electromagnetic field created outside the body produces potential distribution within the body, thereby generating electrical potential between the sensing electrodes as well.…”

The Fiftieth Anniversary of Cardiac Pacing

“…9 By 1962 10 transvenous pacemaker implantation was demonstrated and, by 1965, 11 was widely practiced. In 1962 the first pacemakers capable of sensing cardiac activity to modify their own function, in this case sensing the atrium to pace atrial synchronously, 12 were introduced. With transvenous implantation and the sensing of the heart to modify pacemaker and cardiac function, the modern era of cardiac pacing began.…”