Those with defibrillators can reduce their risk of death without losing their quality of life, according to a study released Wednesday. But patients who receive a shock from the device need to be aware that it could be a sign of a worsening condition, researchers say.
The study and the review were published in the New England Journal of Medicine.
Implantable cardioverter-defibrillators (ICDs) lower the risk of death from sudden cardiac arrest (SCA) among patients with heart failure, and don't have long-term adverse effects on quality of life, according to the study by researchers at Duke University.
Still, doctors Jeff Healy and Stuart Connolly, who reviewed the study, said that steps need to be taken to reduce the occurrence of shocks because a shock is an indication of a meaningful change in the patient. The arrhythmia that causes a shock is a signal of deteriorating health.
ICDs are implanted into the upper part of a patient's chest and monitor the heartbeat. They shock the heart with electricity if the heartbeat becomes irregular. Some patients find the shocks painful or unsettling, while others become anxious at the thought of being shocked.
Dr. Daniel Mark and colleagues studied 2,521 patients enrolled from 1997 to 2001 in the Sudden Cardiac Death in Heart Failure Trial. Researchers interviewed each participant four times over a 30-month period. Patients with the ICDs had higher quality of life scores at 3 and 12 months, than those in other groups.
"Interestingly, we found that patients who happened to experience a shock from the ICD within 30 days before their quality of life interview reported a significant decline in their assessment of their overall physical and emotional health," Mark said.
However, after one year, researchers found no significant difference in the patients' attitude towards their quality of life, he said.
Healy and Connolly wrote that "physicians need to consider the possible causes of shocks, including a worsening of heart failure and myocardial ischemia...Shocks should prompt physicians to ensure that all appropriate therapies to improve the prognosis for heart failure are being used."
