Reprinted with
permission
from: Electricity
and the Heart: An historical perspective
Early History of Cardiac Pacing and
Defibrillation
Seymour
Furman, MD
Editor in Chief, PACE, Founder and Past President of
NASPE, Principal Investigator of Electricity and Heart, The Albert
Einstein College of Medicine.
Address for correspondence: Seymour
Furman, MD, Montefiore Medical Center, 111 E 210 St. Bronx, NY
10467-2409
E mail: furman@ipej.org
Introduction
The Electricity and the Heart website1 is intended to facilitate the collection,
cataloging and presentation of historical information about technical
and scientific advances in cardiac devices. Over the course of the past
century as the
fields of cardiac pacing and electrophysiology have evolved, the
technological
devices used by physicians and researchers has been a fascinating and
rapidly
changing portion of the history of the fields. NASPE's Oral History
Project
houses hundreds of devices collected over the years that illustrate the
evolution from crude and simple machines to the sophisticated and
advanced
technological wonders that are used in the field today. The photos and
descriptions
of many of these devices show just how far we have come in the
advancement
of treatment and patient care.
The 1930s: Hyman Pacemaker
In 1930 Albert S. Hyman decided on the need to resuscitate persons
whose hearts had entered standstill. He did not distinguish between
cardiac arrest and ventricular fibrillation and his published articles
did not discuss
heart block. He had previously described the use of intracardiac (right
atrial) injections of many medications, including epinephrine. Among
the
techniques he also devised was a machine to produce electricity to be
introduced
into the heart by a needle plunged through the chest wall, and would
cause
it to beat. With his brother, an engineer, they developed and patented
the
"artificial pacemaker" operated by a hand crank and spring motor which
turned
a magnet (DC current generator) to supply the electricity. The device
was
used in the New York area and received press coverage, though not
acceptance
by the medical community. The concept was also criticized as
interfering
with natural events.
The 1940s: Hopps Pacemaker-Defibrillator
In
1949 Wilfred Bigelow, MD of the University of Toronto and his trainee,
John C. Callaghan, MD, began developing hypothermia for use in reducing
metabolism and producing bradycardia during which intracardiac
procedures
could be performed. At a temperature of 21C, asystole occurred. Cardiac
contraction could not be restored sufficiently rapidly by re-warming
the
body, so experimentation with stimulation of the sino-atrial node was
begun.
An engineer, John A. Hopps, was assigned by the National Research
Council
of Canada to participate. He designed the first catheter electrode for
cardiac
stimulation, which was introduced via the right external jugular vein
of
the experimental animal and a vacuum tube operated external pacemaker.
Atrial
pacing was readily achieved and control of the cardiac rate was
accomplished2.
The photo seen is a reproduction of the original
Hopps Pacemaker-Defibrillator, which was constructed by George Szarka.
It is
a working model duplicating the original Hopps circuit. The front panel
is of clear plastic to allow visualization of the circuit element.
The 1950s: Zoll Pacemaker
In 1950 Paul M. Zoll began work on an external pacemaker which
was to stimulate the heart across the closed chest. The pacemaker was
line current operated and put out a maximum of approximately 150 volts.
Output voltage and stimulation rates were controlled from the front
panel of the pacemaker. The electrodes were two one-inch diameter metal
discs placed on the right and left sides of the chest, held in place by
a rubber strap and making contact via a conductive electrode jelly. By
1952 the first papers concerning the pacemaker were published3 and revolutionized
the concept of resuscitation of the patient with heart block and
asystole.
Stimulation of an adult required approximately 100 volts, some
sufficing
with less and others requiring higher voltage. Stimulation was painful
and
required sedation. Prolonged stimulation produced local skin burns. The
longest
period of stimulation reported was 11 days. Beginning and end of
stimulation
was by manual switch operation. By 1956, the need for stimulation via
myocardial
wires placed during surgery caused the placement of an outlet labeled
"internal"
and from the output voltage was reduced to one tenth.
For further reading, please visit the Electricity and
the Heart Website: http://www.naspe.org/library/electricity_and_the_heart
References
1. The Electricity
and the Heart website: http://www.naspe.org/library/electricity_and_the_heart/
2. Bigelow
WG, Callaghan JC, Hopps JA. "General hypothermia for experimental
intracardiac surgery." Ann. Surg. 1950; 1132: 531-539.
3. Zoll PM.
"Resuscitation of the heart in ventricular standstill by external
electric stimulation." N Eng. J. Med. 1952; 247:768-771.
