A chronically implanted system for automatic defibrillation in active conscious dogs. Experimental model for treatment of sudden death from ventricular fibrillation.

Abstract

Ventricular defibrillation was acheived in active conscious dogs with a chronically implanted automatic system composed of a defibrillator and an alternating current fibrillator. The hermetically sealed defibrillator is encased in titanium, weighs 250 g and has a volume of 145 ml. The sensor continuously monitors ventricular electircal activity and recognizes fibrillation by the absence of isoelectric potential segments. Fibrillation is induced by placing a magnet over the implanted fibrillator. The resulting syncope closely resembles the clinical entity of sudden death, while the defibrillator automatically restores normal rhythm with a truncated exponential pulse of 30 J, 15 seconds after the onset of the arrhythmia. The operational status of the defibrillator can be tested in vitro and noninvasively in vivo with an external analyzer. This experimental model allows for the first time a long-term study of the automatic implantable defibrillator approach to prevent sudden death from ventricular fibrillation under a variety of physiopathologic conditions.

The Role of Implantable Cardioverter Defibrillators in Ischemic and Non-Ischemic Cardiomyopathy and Effect on Mortality and Sudden Death

“…They believed that a shock delivered directly to the heart would require much less energy, and that a device to deliver it could be made small enough to be implanted in the human body. Mirowski implanted the first device in a human in 1980 and in 1985, the Food and Drug Administration (FDA) approved the use of ICDs, (Mirowski and Mower, 1973;Mirowski et al, 1978;Mirowski et al, 1980).…”

Implantable Cardioverter-Defibrillators in Sudden Cardiac Death Prevention: What Guidelines Don't Tell

“…Each decade played a distinctive role in the evolution of ICD therapy. From the late 1960s until the first patient implant in 1980 [32], Mirowski's concept of a "standby automatic defibrillator" [33,34] met with skepticism [35] and concern about the practical difficulties in designing and manufacturing such a device [36,37]. After the first human device implant in 1980, clinical acceptance of the concept was initially slow, but began to accelerate after Food and Drug Administration approval in 1985 and Medicare coverage for limited indications in 1986.…”

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“…Each decade played a distinctive role in the evolution of ICD therapy. From the late 1960s until the first patient implant in 1980 (1), Mirowski's concept of a "standby automatic defibrillator" (2,3) met with skepticism (4) and concern about the practical difficulties in designing and manufacturing such a device (5,6). After the first human device implant in 1980, clinical acceptance of the concept was initially slow, but began to accelerate after Food and Drug Administration approval in 1985 and Medicare coverage for limited indications in 1986.…”