Stop-&-Go Shocks

Few crises in affairs of the heart are more dreaded by physician, surgeon and patient alike than ventricular fibrillation --in which the heart's built-in electrical timing system fails and its lower chambers flutter futilely. Instead of beating purposefully and pumping blood to the whole body, they twitch ineffectively and pump nothing. There is no heartbeat. Doctors have tried to reverse the rapidly fatal process with a variety of electronic gadgets, but until recently no defibrillator has been able to do the job consistently. Now, some daring and resourceful doctors have become so sure they can restore a twitching heart to its normal beat that they are deliberately subjecting their patients to fibrillation as an aid to difficult heart surgery.

DC v. AC. When a patient's heart is laid bare for an operation inside it, the surgeon wants the heart to lie relatively still. While a heart-lung machine takes over the patient's circulation and chills his blood, the University of Minnesota's Dr. Morris J. Levy and famed Surgeon C. Walton Lillehei reported to the American College of Surgeons, they shock the heart into fibrillation with low-voltage current. They have left a heart fibrillating for as long as 2 1/4 hours, and for an average of an hour in 45 cases. At operation's end, they switch the heart back to normal activity with a delicately timed electrical countershock.

In the past, a restarting shock has usually been a jolt of alternating current, but surgeons have sometimes had to give many shocks, and even then have failed to get the heart going again. Far better, reports Harvard's Dr. Armand A. Lefemine, is a direct-current defibrillator. The DC shock may run as high as 7,000 volts, but the current is applied for only one four-hundredth of a second.

The Harvard researchers used their gadget first on a patient who had just had twelve AC shocks at 25 volts with no result. The DC machine worked promptly, and it has now been used successfully on more than 30 patients. In two cases, it did its job when the electrodes were merely applied to the skin--suggesting widespread value for countless patients whose episodes of fibrillation have nothing to do with surgery.

On the Line. To make such application universally available, the machines should be portable and battery-operated. And a Johns Hopkins team, says Dr. James R. Jude, has perfected just such a portable defibrillator. It weighs only 45 lbs., can be powered by dry cells or a car battery. Through electrodes applied to the skin, one below the throat and one below the left nipple, the compact machine delivers 2,000 to 2,200 volts in a one-two pulse--first in one direction, then in the other. When a heart-disease patient or an electric-shock victim has a fibrillation attack, says Dr. Jude, first-aid methods (chest massage and mouth-to-mouth breathing) must be used promptly, and kept up until the doctor arrives with the electrical defibrillator. Electric-linemen, who are frequent victims of shock fibrillation, are being trained to use the machine on their buddies without waiting for a doctor.

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