February 15, 2013 by Paulina Gawod
Doctors at Drexel University’s College of Medicine and Hahnemann University Hospital were among the first in the country to use a new type of defibrillator in clinical trials. The device is called the subcutaneous implantable cardioverter-defibrillator.
The college is now one of the first institutions to participate in experiments with the device after it received approval from the Food and Drug Administration.
“This is the biggest breakthrough we’ve seen in cardiology since the invention of the VAD (ventricular assist device) in the 1980s,” Dr. Steven Kutalek, director of cardiac electrophysiology and associate chief of the Division of Cardiology at DUCoM, said.
Conditions like arrhythmia, ventricular fibrillation and tachycardia are different ways in which the heart beats irregularly. Defibrillators return hearts to their correct rhythms by delivering small amounts of electrical energy and can act as pacemakers if necessary, resetting hearts to their natural beat. Traditionally, defibrillators run wires through the heart tissue, but because of movement of the heart muscle, leads can break or even cause infection in the tissue.
The S-ICD is less invasive than traditional defibrillators because it does not touch the heart. It sits under the skin, on the ribcage with a single lead wire that goes near the heart. The device minimizes invasiveness in surgery and clinical complications, eliminates risks of vascular injury or infection, and uses more complex technology to classify heart rhythm more accurately. It is inserted by a small incision and does not require X-ray guidance for placement. It allows treatment for those who can’t use standard defibrillators or have a high risk of infection.
“Because of its placement, the S-ICD offers patients more mobility after implant and a lower risk of systemic infection,” Kutalek said.
One of the drawbacks of the device is that it cannot be used as a pacemaker and can only be used for life-threatening rapid heartbeats. Many doctors are waiting to see results of long-term studies before they fully accept the S-ICD. They feel that it will have a role limited to very specific populations. DUCoM and Hahnemann University Hospital were among the first to evaluate the device’s long-term effects, and studies are ongoing. Optimistically, the S-ICD is a huge advancement, and in FDA yearlong trials, it has shown an all-cause mortality rate of 3.7 percent, lower than standard devices.