Charles Craddock is one of millions of people who needs an implantable defibrillator to help monitor his heart rhythm and prevent the occurrence of sudden cardiac death—or death resulting from an abrupt loss of heart function.
Defibrillators are complex devices that deliver internal electric shocks to a patient’s heart whenever a life threatening cardiac rhythm is detected. Craddock, 57, was diagnosed with and treated for ischemic cardiomyopathy—a deterioration of the heart muscle due to insufficient blood supply—in March 2003.
Since that time, he has received several implantable defibrillators. Almost a year ago, after receiving at least 17 painful shocks from his defibrillator for episodes of extremely rapid, life-threatening heart rates, he realized that his defibrillator, aside from delivering painful shocks, could also fail to save his life.
“One night, after two hours of my heart racing, my wife said, ‘Enough,’” he says.
Craddock’s wife, Elizabeth, drove him to the emergency room at the Cincinnati Department of Veterans Affairs (VA) Medical Center, where his heart condition was further evaluated.
A decision was made to perform a radiofrequency catheter ablation in an attempt to prevent future episodes of ventricular tachycardia—or fast heart rhythms originating in the heart ventricles.
Radiofrequency catheter ablation—a somewhat new technique— is a nonsurgical, catheterbased procedure that uses real-time recording and processing of the electrical signals inside the heart. It uses X-rays for continuous imaging of the catheters inside the heart, as well as different mapping systems that help in positioning the catheters.
During radiofrequency ablation, a mild, painless radiofrequency energy pulse is delivered to areas that have electrical abnormalities, destroying carefully selected cardiac cell bundles that cause the specific rhythm problems.
Alex Costea, MD, and Mehran Attari, MD, both electrophysiologists and assistant professors of medicine in the cardiovascular diseases division at UC, performed not one but two ablation procedures on Craddock.
“Due to the significant scarring of his heart muscle, Mr. Craddock’s heart rhythm would often become unstable and life threatening,” Costea says. “His ICD, or implantable cardiac defibrillator, recorded multiple episodes of ventricular tachycardia, a potentially lethal condition with heart rates above 150 beats per minute.
“He hasn’t had any more abnormal rhythms since the second procedure was performed.” Craddock says he feels great and that his quality of life has improved tremendously. “I’m able to get out and do more than what I have been able to do in the past,” he says.
“My wife and I will go for walks, and I can walk up to a mile and a half on good days whereas before I was straining to do a quarter of a mile.”
He adds that he is able to do more volunteer work at his local kingdom hall, or church, since the procedure. Attari and Costea, the two electrophysiologists at the VA and University Hospital, are using this and other evolving technologies to map and image the heart, helping pinpoint the exact location of cardiac rhythm disturbances.
Intracardiac ultrasound is another key technology helping doctors in the cardiac electrophysiology labs at the VA and University Hospital to gain valuable information regarding the areas in the heart that need ablation.
“This procedure allows a detailed evaluation of the inner surface, or lining, of the heart and valves, increasing the safety of the procedures and helping determine if there are abnormalities, like myocardial scars,”
Costea says. In addition to X-rays and intracardiac ultrasound, these teams are using a GPS-like mapping system, called CARTO, to help guide them during cardiac procedures.
Using the CARTO system, a set of three magnets is placed under the operating table while another small magnet is attached to the ablation catheter tip.
Through a computerized system, the position of the ablation catheter is continuously calculated and recorded in three dimensions, allowing precise catheter navigation to the desired location with a precision of less than one millimeter.
The CARTO system also records voltage and electrical timing of the specific point within the heart chambers.
“With these tools, we are able to obtain very detailed information about the electrical network of the heart and tailor care to the patient’s specific problem,” Costea says. “These technologies allow us to more efficiently, safely and effectively provide cardiac care in patients with complex, life threatening heart rhythm disturbances.”
Craddock couldn’t agree more—especially when it comes to the ablation procedure.
“I’m a big believer in it,” he says. “It has improved my quality of life. I am very thankful to the doctors and their staff and am very glad we have this technology available in Cincinnati.”