Cindy Zinkovich or
Embargoed for Release Until After 9:30 a.m. PDT, Wednesday, May 6
PACEMAKERS GREATLY IMPROVE QUALITY OF LIFE
SAN DIEGO -- Older people report a dramatic improvement in their quality of life after being given pacemakers to help their hearts beat regularly, according to a study presented today at the 19th Annual Scientific Sessions of the North American Society of Pacing and Electrophysiology (NASPE).
"This ranks right up there with knee and hip replacements and cataract surgery as far as the significance of improvement in elderly patients' lives," said Gervasio Lamas, M.D., chief, division of cardiology at Mount Sinai Medical Center, and associate professor of medicine at the University of Miami School of Medicine, Miami Beach, Fla. "Often when we do things for older people, there's not much improvement, but after getting a pacemaker, the people in our study said they're more active, they feel better, they're happier and they can do things with friends."
Smaller than a pager, a pacemaker is implanted in the chest and wired to the heart to help it beat regularly. Although there has been concern that too many elderly patients were receiving pacemakers, this study suggests they are being given for appropriate reasons and are not being overused, said Dr. Lamas.
Pacemakers were found to be of great benefit in improving seniors' lives. The patients said they noticed a dramatic improvement in how they felt physically and emotionally, and in their activity levels. The results were tabulated from quality-of-life questionnaires filled out by 310 patients immediately before and three months after implantation of the pacemaker. Dual- Versus Single-Chamber Pacemakers
The findings were an aspect of the Pacemaker Selection in the Elderly (PASE) trial. The study also suggests that, contrary to conventional wisdom, there may be little benefit to converting patients who have had single-chamber pacemakers for many years to dual-chamber pacemakers. Single-chamber pacemakers pace the heart's lower chambers, or ventricles, while dual-chamber devices pace both the ventricles and the upper chambers, or atria.
"Many doctors are of the mindset that quality of life will improve with a dual-chamber pacemaker and that people with single-chamber pacemakers should receive the upgraded device," said researcher Robert S. Mittleman, M.D., director of the section of electrophysiology and pacing at the University of Massachusetts Medical Center, Worcester. "Our study suggests that for many patients, that many not be the case."
Dual-chamber pacemakers are much more expensive than single-chamber devices and implantation is more complicated, as they require a second wire, or lead, inserted into the heart.
The study compared the quality-of-life findings reported by people with single-chamber pacemaking versus dual-chamber pacemaking. All 54 patients had been implanted with dual- chamber pacemakers programmed to single-chamber mode. At the end of the 30-month study, all were switched to dual-chamber pacemaking.
The group as a whole reported an improvement in activity level, but little improvement in the quality of life when switched to dual-chamber pacing mode. The exception was a group of 15 (28 percent) patients who had suffered heart attacks. They reported they had less pain, felt they were physically more capable and felt more energetic when switched from single-chamber to dual- chamber pacing.
"Although patients benefitted, we don't know yet which patients would benefit enough to justify the additional cost and complexity of the implants," said Dr. Mittleman. "The data do suggest that patients who have had a heart attack in the past might be the best candidates for the more complex dual-chamber models. We may be able to answer those questions after further data analysis." Understanding Pacemaker Syndrome
In a related study, researchers found that a simple test can identify patients at risk for pacemaker syndrome, a condition in which the patient suffers from shortness of breath, fatigue, light headedness and even fainting. Pacemaker syndrome strikes about 10 percent of people who have single-chamber pacemakers. The problem can be corrected with a dual-chamber device.
"In a worst-case scenario, pacemaker syndrome can cause someone to faint while driving," said Igor Singer, MBBS, professor of medicine and director of electrophysiology and pacing at the University of Louisville, Kentucky. "With this test, doctors can identify up front that, for that patient, a dual-chamber pacemaker is important."
Up to 40 percent of the 136,000 pacemakers implanted annually worldwide are the single- chamber variety, said Dr. Singer. Single-chamber pacemakers are often chosen over dual- chamber pacemakers because they are significantly cheaper and less complicated to implant, he said.
Dr. Singer and his colleagues studied 10 patients implanted with dual-chamber pacemakers switched to single-chamber pacing mode by external programming. Half of them had been previously identified as being at risk for pacemaker syndrome, while the remaining 5 were identified as not at risk. They were put on a table that tilts the patient from a supine position to a standing position and were given a simple, noninvasive test that measures oxygen saturation in the brain.
The test was 100 percent effective in predicting patients with pacemaker syndrome; oxygen saturation levels and/or systemic blood pressure dropped when patients with the syndrome were titled to a standing position, but remained constant for those without the syndrome.
"Some doctors implant single-chamber pacemakers in the mistaken belief that that's all the patient needs," said Dr. Singer. "But some patients have problems because single-chamber devices don't provide synchrony between the top and bottom chambers of the heart, and the amount of blood pumped may decrease by up to one-third."
A paper on the study of quality of life for people with pacemakers is being presented by Catherine Yoon, M.Ed. Co-authors in addition to Dr. Lamas are: Francisco Lopez-Jimenez, M.D., M.Sc.; John Orav, Ph.D; Bruce Stambler, M.D., Kenneth Ellenbogen, M.D.; and Lee Goldman, M.D.
Co-authors of a paper on the study being presented by Dr. Mittleman are E. John Orav, Ph.D.; Lee Goldman, M.D.; Kenneth A. Ellenbogen, M.D.; Stephen Huang, M.D.; and Gervasio A. Lamas, M.D.
Co-authors of a paper on the study being presented by Dr. Singer are Harvey Edmonds Jr., Ph.D.; Aida Sehic, M.D.; and Ted J. Strickland, Ph.D.
Based in Natick, Mass., the North American Society of Pacing and Electrophysiology is a professional organization of physicians, scientists and allied professionals throughout the world dedicated to the study and management of cardiac arrhythmias. Its mission is to improve the care of patients by promoting research, education and training, and providing leadership towards optimal policies and standards.
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[Editors note: For more information, contact the NASPE Web site at www.naspe.org.]
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