Ventricular tachycardia and ventricular fibrillation are life-threatening heart arrhythmias where the heart beats so fast and irregular, it actually stops pumping blood and sudden cardiac arrest occurs.
To prevent sudden death in patients who have these conditions, implantable cardioverter-defibrillators (ICDs) have been used for nearly three decades. These battery-powered devices are placed under the skin and monitor the heart rate. Wires run from the device into the heart, where they deliver an electric shock to restore a normal heartbeat if a severe arrhythmia is detected. However, physicians at the UF Health Cardiovascular Center offer a newer alternative – subcutaneous ICDs.
“Unlike traditional ICDs, the subcutaneous ICD doesn't physically enter the vascular system or heart,” said John Catanzaro, MD, a UF Health cardiac electrophysiologist. “It’s a new generation of the device, which is the first of its kind to have wires under the skin and not in the blood vessels or heart.”
FDA-approved in 2012, the S-ICD is placed under the left armpit region, and the wire is placed under the skin along the left side of the breastbone. This is advantageous to patients as the S-ICD does not go through the central veins in the chest nor does it attach to the tissue in the hear chamber, which reduces the chance of infection.
Ventricular tachycardia, or v-tach, occurs when an abnormal rhythm begins in the lower part of the heart. Symptoms often include chest discomfort, fainting, lightheadedness or dizziness, palpitations and shortness of breath. If left untreated, it can lead to a life-threatening condition called ventricular fibrillation or v-fib – a condition where the heart quivers instead of pumping – a common cause of sudden cardiac arrest.
“This device senses a cardiac arrest, defibrillates and briefly paces to restore the normal heart rhythm,” Catanzaro explained. “It can discriminate fast rhythms between the top or bottom chamber of the heart — meaning we can tell where the abnormal rhythm is just by using the S-ICD.”
While both devices monitor the heartbeat and automatically deliver an electrical shock to the heart if a potentially deadly rhythm is detected, the SICD reduces the chance for infection and is more accurate in detection.
“Right now the SICD is a niche product and has the capability of becoming the choice in the future,” Catanzaro explained.
In addition to this device, Catanzaro recommends lifestyle changes and medical therapy to give the function of the heart the most chance of recovery.
“A healthy diet, cardiac rehab and compliance with medication is also important,” Catanzaro said.
UF Health Jacksonville offers comprehensive treatment and prevention of v-tach, v-fib and a variety of other cardiac conditions. Different types of implantable cardiac defibrillators are available depending upon the indication for a variety of patients. For more information, visit UFHealthJax.org/cardiology.
John N. Catanzaro, MD, FACC, FESC, FHRS
Associate Medical Director, Electrophysiology Program; Interim Program Director, Clinical Cardiac Electrophysiology Fellowship; Associate Program Director, Clinical Cardiac Electrophysiology Fellowship