Implanted in a human abdomen, the cigarette pack-sized device continuously monitors cardiac rhythm. The occurrence of an arrhythmia, however, jolts it into action, resulting in the delivery of as many as four low-energy defibrillatory pulses to the heart.
Clinical evaluation of this automatic implantable defibrillator is still in progress at Stanford (Calif) Medical Center, The Johns Hopkins University School of Medicine, Baltimore, and, soon, some other centers. But, according to Mieczyslaw (Michel) Mirowski, MD, associate professor of medicine at Hopkins and director of the coronary care unit at Sinai Hospital, Baltimore, so far, so good.
The model being tested costs about $6,000 and is manufactured under the trademark AID by Medrad/ Intec Systems Inc, Pittsburgh, which helped design it. Since 1980, the device has been implanted in 43 persons who already had survived "at least two episodes of arrhythmic cardiac arrest not associated with acute myocardial infarction," says Mirowski, who