New Defibrillator Prevents Cardiac Arrest Without Placing Leads into the Heart Itself

March 31, 2014

AUT Medicine San Antonio cardiologist, Dr. Manoj Panday, will implant a subcutaneous internal cardioverter-defibrillator (S-ICD) into a patient at University Hospital at noon today (Monday, March 31 ). The patient, who is at high risk for sudden cardiac arrest, will be the first University Health System patient to be treated with this new device. The surgery is expected to last one hour.

Dr. Panday performed two S-ICD implantations in the past month at the South Texas Veterans Health Care System. UT Medicine is the clinical practice of the School of Medicine at The University of Texas Health Science Center at San Antonio. University Hospital and the VA Hospital are two of the School of Medicine's teaching hospitals.

Like other defibrillators, the S-ICD system is a battery-powered device implanted underneath the skin that can save a patient's life by delivering a shock to the heart. But unlike traditional defibrillators, the electrical lead for the S-ICD is implanted within the chest wall, eliminating the need to screw one or more leads into the heart itself. "This reduces the risk of puncturing the heart or lungs, or injuring blood vessels through which we have had to track the leads," said Dr. Panday. "This reduces the patient's risk of contracting a systemic infection, such as endocarditis. It is advantageous that the new approach does not involve touching the heart or blood vessels."

Dr. Panday, with the UT Medicine cardiology practice, is one of the first physicians in South Texas to be trained on how to implant this device. It is new technology and a new procedure that is not done yet in many parts of the country. The S-ICD system, made by Boston Scientific, only recently gained U.S. Food and Drug Administration approval for treating patients who are at high risk for sudden cardiac death.

"The gentleman to be treated at University Hospital has a cardiomyopathy (weakening of the heart muscle with a low ejection fraction, which is a measure of heart pump function). The patient has scarring in the heart that puts him at risk of developing ventricular fibrillation (quivering of the heart without organized electrical activity)," said Dr. Panday. "This type of rhythm results in sudden death if not shocked quickly. Unfortunately, these patients often do not survive their first episode."

The device detects abnormal heart rhythms and can quickly deliver an 80 Joule shock to restore a normal rhythm. The device's generator is implanted under the skin and contains a battery that generally lasts five years and can be replaced with an outpatient procedure. This breakthrough technology marks the first time that an implantable device can prevent sudden cardiac arrest and save someone's life without having a lead implanted inside the vascular space and heart. 'With a defibrillator implanted, survival can be increased by 30 percent in high-risk patients. There is less overall procedural risk to the patient, but there is similar life-saving benefit with the S-ICD," said Dr. Panday.