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Release: July 2, 2001

Patient receives new type of pacemaker at the UI

IOWA CITY, Iowa -- A University of Iowa Health Care patient recently became the first person in Iowa to receive a new type of pacemaker, developed to correct two different heart rhythm problems and help the young woman get back to an active life.

The device adds new technologies to the standard pacemaker function of preventing the heart from beating too slowly. Physicians hope that this pacemaker, currently in the final stages of evaluation for approval by the Food and Drug Administration (FDA), may prove to be a good alternative to medication for patients with an abnormal heart rhythm called atrial flutter.

Atrial flutter is a rapid heart rate caused by a loop of current that circulates in the top chambers (atria) of the heart. This condition can result in the heart pumping less blood to the body, making physical activity difficult. Atrial flutter can also increase the risk of stroke.

The 33-year old patient treated at the UI had an abnormally slow heart rate as well as episodes of atrial flutter, which were being treated with medication. Unfortunately, the medication used to prevent the fast atrial rhythm made her slow heart rate even worse.

"We could have used a standard pacemaker to correct her slow heart rate and kept her on the medication to prevent the flutter," said Ian H. Law, M.D., UI assistant professor (clinical) of pediatrics. "But it seemed preferable in this case to use the new pacemaker to correct both problems and take her off the medication, which has potentially dangerous side-effects.

"Overdrive pacing, when the pacemaker briefly paces the heart faster than the atrial flutter, can break the heart out of the abnormal rhythm. This unique pacemaker can apply the overdrive pacing only when it is needed," he explained.

Advanced software also allows the device to sense heart-rate changes that precede atrial flutter. The pacemaker can then gently alter the heart rate to prevent the flutter from occurring.

Law said that there is a growing group of patients who could benefit from this device's ability to correct the abnormal rhythm.

While advances in surgery in the past 40 years have greatly increased the chances of survival for children born with congenital heart problems, these life-saving surgeries scar the heart tissue. Scarring appears to predispose patients to develop abnormal heart rhythms such as atrial flutter. Although these complications can often be treated effectively with medication, having to take a medicine for life is not an optimal solution.

"If a patient survives long enough after complex heart surgery, it is almost inevitable that they will develop the atrial flutter," Law said. "Hopefully, this group of patients will benefit from the technology used in this new pacemaker."

The pacemaker is currently being evaluated in a multi-center trial for FDA approval. Although the UI is not part of this study, a "compassionate-use" rule, which applies to such device trials, allowed the UI to use this device in an eligible patient. Under specific rules laid down by the UI Institutional Review Board, the patient was fully informed of the device's FDA status and of the nature of the study. Law also discussed with the patient the advantages and potential risks of the device prior to the decision to implant the device.

The new pacemaker recipient returned to the hospital one month after receiving the pacemaker for a check-up. Once it was determined that the electrical leads had remained in a stable position, the overdrive pacing feature of the pacemaker was activated. The pacemaker was immediately able to detect an atrial flutter and correct it.

"With the standard pacemaker function alone, she already felt much better," Law said. "If the novel overdrive pacing also continues to work for her, allowing her to stay off the atrial flutter medication permanently, that will be extremely beneficial."

Law hopes that advances such as this unique pacemaker can improve the quality of life for the growing number of patients with abnormal heart rhythms.

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