New wiring simplifies defibrillator implants

Like many heart-failure patients, Ronald Grzymala was in a bind.

His weakened heart put him at risk of sudden cardiac arrest, so he needed to have a device placed in his chest that could jump-start his heart if it stopped. But he couldn't safely undergo the complicated implantation surgery because of other health problems.

Six months ago, the Southampton, N.J., resident found a solution at the Hospital of the University of Pennsylvania. He had an experimental implantable cardioverter defibrillator (ICD) installed during a simple outpatient procedure that took less than an hour and didn't even require X-ray imaging.

Like all ICDs, the new one has a small, battery-powered generator that can send an electric shock. But the new system eliminates the most difficult, breakable, malfunction-prone part of the conventional ICD - the electrical wires, or leads, that are threaded through a vein and placed in or on the heart.

Instead, the lead runs from the generator to the breastbone, where it is anchored with a few stitches. The device can detect heart stoppages without directly touching the organ, just as an electrocardiogram can capture heartbeats through electrodes placed on the chest.

Only three minor chest incisions are needed to place this under-the-skin, or subcutaneous, ICD.

"It's the only one I could have used," said Grzymala, 68.

The S-ICD, made by Cameron Health Inc., has already been approved in Europe. To get U.S. approval, the company is paying for a clinical trial under way at 30 U.S. sites, including Penn, Cooper University Hospital and Drexel University College of Medicine.

Even assuming the S-ICD proves to be as safe and effective as older systems delivered through a vein, it will not replace them.

The standard intravenous ICD can not only jump-start a heart with an electrical shock, it can provide pacing for a heart that beats too slowly or too rapidly.

The new subcutaneous system, in contrast, is only for a patient whose heart may suddenly stop beating, either because it is damaged and weak, or because an electrical abnormality triggers a chaotic quivering called ventricular fibrillation.

Still, eliminating the intravenous lead is likely to expand ICD usage, experts say.

No longer will implantation require a physician with specialized training, skill and equipment.