Hope for the Heart: Advances in Treatment
Today two-thirds of people survive their heart attacks, thanks to medical advances. Learn how some of these medical marvels evolved.
A Lifesaving Shock to the Heart continued...
Michel Mirowski, MD, had lost a dear friend to sudden cardiac death, caused by an arrhythmia, or abnormal heart rhythm. He was determined to develop an implantable device that could correct potentially fatal arrhythmias before the patient was even aware of a problem. With colleague Morton Mower, MD, he approached Stephen Heilman, MD, at a company called Medrad in Pittsburgh, to carry out the research and make a commercial product.
"Having the idea and actually making a practical device are two different things," says Alois Langer, PhD, an electrical engineer who joined the team in 1972, with a freshly minted degree from MIT. He was charged with figuring out how to build the ICD the medical doctors envisioned.
Pacemakers that keep a slow heart beating normally had already been in use for years. But no one had attempted to make an automatic, implantable defibrillator, which would shock the heart out of an abnormal rhythm like ventricular fibrillation. In ventricular fibrillation, the regular electrical impulses of the heartbeat get disorganized, ventricles flutter chaotically, and the heart doesn't pump blood. It is fatal in minutes or even seconds.
Many doctors were skeptical, even hostile, to the idea, so Mirowski's team experimented and tinkered with their device for nearly a decade before attempting a human test. "We weren't getting a lot of support from the medical community," Langer says, somewhat understating the opposition.
"At the time, this was a very radical approach," Resar says. Most doctors thought that drugs then available were adequate for controlling arrhythmias, and that an implantable defibrillator was not only improbable but also unnecessary.
In 1980, at Johns Hopkins University Hospital, the prototype ICD was implanted in a patient. It was roughly the size and weight of an iPod or pager, placed in the abdomen with wires running up to the heart.
Langer says two prototypes were made, just in case someone dropped one on the floor. "The first one really did get dropped," he says.
After the device was in, the researchers had to test it, which meant purposely inducing ventricular fibrillation in the patient. Having done so, they waited for the device to switch on and shock the heart back into a normal rhythm. "That seemed like an eternity," Langer says, as the seconds ticked by. But it worked.
"The first indications for use were fairly strict," Langer says. To qualify for an ICD, you had to have experienced sudden cardiac death and been resuscitated. Today, the devices are used much more broadly, and they're a lot smaller. People with heart failure routinely get them. Vice president Dick Cheney has one.
Langer moved on from ICDs to found Cardiac Telecom Corporation, where he developed a telemetry system that keeps track of a heart patient's vitals at home, and alerts doctors or calls an ambulance if something goes wrong.