Until last winter, Joseph Moniz, 50, a Fall River man with congestive heart failure was waiting, like 4,000 other Americans, for a heart transplant to save his life.
He never got it. But he got something better: a small device called an implantable cardioverter defibrillator (ICD) like the one Dick Cheney got, a familiar gadget but with a new twist.
Like older defibrillators, Moniz’ device can shock his heart back to normal if the lower chambers, or ventricles, start beating in a rapid, life-threatening rhythm. This kind of arrhythmia, called ventricular fibrillation, causes 350,000 sudden deaths every year.
But the new device in Moniz’ chest can also do something else – re-synchronize the beating of the ventricles so that they work efficiently. This is a potentially a huge boon for many of the 5 million Americans with congestive heart failure, a condition in which the heart beats inefficiently and fluid accumulates in tissues.
Other heart patients, at a handful of medical centers around the country, are getting a variety of other novel treatments for the electrical problems in their hearts, including a promising technique called catheter ablation for atrial fibrillation and other arrhythmias.
For decades, cardiology was ruled by medical plumbers, doctors whose main concern was fixing crucial coronary arteries that become clogged with cholesterol. But now, a number of (literally) electrifying advances has put a new batch of cardiac gurus in the limelight as well: the cardiac electricians, or more precisely, the electrophysiologists.
In the heart, the electrical signals that control rhythms originate in a built-in pacemaker, the SA, or sinoatrial node, a small bit of tissue at the top of the right atrium. Normally, the SA node produces about 60 heartbeats a minute. The electrical signal spreads through the right and left atrium, then activates the AV, or atrioventricular node, a relay point between the upper and lower chambers.
From there, the electrical signal spreads through the ventricles. After the ventricles contract, the signal dies out and the heart waits for a new signal from the SA node.
When these electrical signals become deranged, cardiac hell can break loose, including atrial and ventricular fibrillations, in both of which the heart beats wildly and very rapidly. Such arrhythmias “are becoming an epidemic” because the risk goes up with age and the population is aging, notes Dr. Valentin Fuster, director of the Cardiovascular Institute and Health Center at Mt. Sinai Medical Center in New York.
But treatments often help. Last March, the New England Journal of Medicine published a major study called MADIT II that was stopped early because the results were so clear. It involved more than 1,200 patients and showed that those randomly assigned to get standard ICDs to shock their hearts back into normal rhythm when ventricular arrhythmias occurred had a 31 percent decreased risk of death compared to those receiving standard drug (non-ICD) therapy. Roughly one million Americans have heart attacks every year, and more than a third wind up with poor ventricular function as a result.)
The new generation of ICDs not only can shock the heart back to normal rhythm but can synchronize the coordination of the ventricles by way of an extra wire, or lead, that runs from a pacemaker in the chest to the left ventricle, the main pumping chamber of the heart.
Several new ICDs – Contak CD by Guidant and InSync ICD by Medtronic – were approved for marketing this summer. (A third such device, Epic HF made by St. Jude Medical, is in US testing now and is on the market in a limited way in Europe.)
Some congestive heart failure patients now getting resynchrozining ICDs are “turning their beepers in and feeling so well with ventricular resynchronization that they no longer need a heart transplant,” says Dr. Lynne Warner Stevenson, co-director of the cardiomyopathy and heart failure program at Brigham and Women’s Hospital.
Just as ever-improving ICDs are transforming care for patients with ventricular arrhythmias, so, too, is catheter ablation improving care for people with atrial fibrillation, a problem that strikes more than 2 million Americans.
In “A Fib,” electrical signals in the heart’s upper chambers, or atria cause the heart muscle to flutter wildly, which in turn reduces the efficiency of the ventricles. This allows blood to pool and form clots that can lead to strokes.
Some people with A Fib don’t mind the symptoms and mainly need to worry about the risk of stroke from blood clots. Others find the erratic heartbeats drive them crazy.
In a recent study published in the New England Journal of Medicine, researchers found that for older patients who were at risk of stroke from atrial fibrillation, treatments to control heart rhythm were no better at preventing death than treatments to control heart rate.
But other data suggest that for people whose main concern is disruption of quality of life because of A Fib, catheter ablation may provide substantial relief.
In this treatment, electrophysiologists place catheters, or tubes, into the heart and use them to send use radio waves to burn away specific, tiny areas, particularly those on veins going from the lungs to the heart, that trigger arrhythmias.
“Until a year or two ago, no one ever thought you could use catheters to approach this problem,” says Dr. Kalyanam Shivkumar, director of interventional cardiac electrophysiology at the David Geffen School of Medicine at UCLA.
Now, says Dr. Davendra Mehta, director of the cardiac electrophysiological lab at Mt. Sinai Medical Center in New York, the technique could become for some patients “the treatment of choice.”
Indeed, catheter ablation is a potential “cure” for atrial fibrillation, says Dr. Laurence M. Epstein, chief of the arrhythmia service at Brigham and Women’s Hospital in Boston, although Dr. Jeremy Ruskin, director of Cardiac Arrhythmia Service at Massachusetts General Hospital, is more cautious. The technique is “results in dramatic outcomes in some patients,” Ruskin agrees, but “the long-term cure rate is only about 50 percent in the best hands.”
Initially, electrophysiologists thought they had to carefully map out the regions of the heart that were triggering the arrhythmias, says Epstein of Brigham and Women’s Hospital.
To do this, doctors threaded a tube (the catheter) through a blood vessel in the groin up to the heart. Under X-ray guidance, doctors then watched on TV screens as they passed the catheter over different regions of heart muscle, recording electrical activity. Areas of the heart that produced bursts of rapid beats were deemed to be arrhythmia trigger centers. To stop the arrhythmias, doctors then delivered radio waves to the troublesome regions.
But recently, electrophysiologists have found that the mapping step is not always necessary because in many cases of atrial fibrillation, the trigger is the region where the pulmonary veins attach to the heart. Destroying this region can get rid of arrhythmias.
Researchers are also experimenting with destroying electrically-dangerous tissue with ultrasound, microwaves and cryogenic techniques that burn by freezing tissue.
There is still, as Ruskin of MGH and others warn, a long way to go before all arrhythmias can be controlled. But it’s “a very exciting area – there’s a tremendous amount happening.”
Nobody needs to tell that to Joseph Moniz, whose electrophysiologist, Epstein of Brigham and Women’s Hospital, says, “He’s like a new man.” Now off the heart transplant list, Moniz is climbing stairs, playing drums and doing other things he thought he’d never do again.
“I washed my truck for the first time in a couple of years,” Moniz says jubilantly. He still can’t work, but says, “I feel excellent.”