ICDs That Shock Less Are Better

Programming choices greatly influence the value of ICD therapy

Shocking news: Patients with heart arrhythmia who have implantable cardioverter-defibrillators (ICDs) fare better when devices are programmed to wait out irregular heart beats that aren’t sustained. Rather than programming devices to react quickly to all beating irregularities—slow heart beats (tachyarrhythmias) and those of shorter duration—a Randomized Trial to Reduce Inappropriate Therapy (MADIT-RIT) showed that ICD therapy is better for patients when devices are “certain” before implementing shock.

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“A patient’s unnecessary exposure to painful shocks and [their] very survival may depend on [programming] choices.”

So, it’s better when physicians program ICDs to ignore the less serious arrhythmias and risk under-detection. Fewer shocks reduce risk for patients.

“The value of ICD therapy is greatly influenced and in many ways determined by the programming choices made by the physician,” says Bruce Wilkoff, MD, Director, Cardiac Pacing & Tachyarrhythmia Devices at Cleveland Clinic. “A patient’s unnecessary exposure to painful shocks and [their] very survival may depend on these choices.”

In a paper Dr. Wilkoff prepared analyzing the results of MADIT-RIT, he emphasizes the responsibility of physicians to properly program ICDs so they don’t over-detect arrhythmias and shock patients every time the heart skips a beat. MADIT-RIT compared typically programmed ICDs to those programmed to reduce shock exposure. Investigators observed less morbidity and improved survival when patients were shocked less.

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“This was not a new type of ICD, but the same ICD therapy available for decades,” Dr. Wilkoff says of the reduced-shock devices. “The only difference was in the programming of the ICD detection and therapy parameters.”

If you’re a candidate for an ICD or currently have a device implanted, talk to your physician at your next tune-up about the sensitivity of your device. Is it programmed to shock your heart back into rhythm before it’s necessary? Wilkoff adds, “The overriding principle is to be certain that there is a sustained tachyarrhythmia before treating the rhythm.”

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