Procedure means better quality of life for more patients
(November 2012) Yale physicians successfully performed what they believe were Connecticut’s first hybrid ECMO-assisted VT ablations—using a procedure that burns the tissue that caused the patients’ irregular heart rhythms.
Yale routinely performs ablations for ventricular tachycardia (VT)—a potentially life-threatening fast heart rhythm that originates in one of the ventricles of the heart. However, in three hybrid procedures performed in October, an extracorporeal membrane oxygenation machine, or ECMO, was used to provide temporary support of heart/lung function for patients whose weak hearts would have otherwise made the procedure extremely risky.
“This is important for patients whose hearts are too weak to withstand an ablation, and who must endure repeated shocks from their defibrillators as a result,” says cardiac surgeon Pramod Bonde, MD, director of Yale’s ECMO program, who worked on the procedures alongside electrophysiologist Joseph Akar, MD, PhD.
Implantable defibrillators are devices that can save a patient’s life by delivering a shock to terminate a life-threatening heart rhythm. These devices have revolutionized the ability to prevent sudden cardiac death, but this comes at a cost for some individuals. While most patients tolerate a shock very well, the shocks are unpredictable, and for some, even a few of them can be psychologically devastating. The uncertainty may cause tremendous anxiety that limits quality of life for some and can even develop into a form of post-traumatic stress disorder.
Doctors often start medical therapy once a shock occurs, however therapy may not prevent future shocks. For some of those patients, radiofrequency catheter ablation is performed to eliminate the electrical short circuits causing the abnormal rhythm.
“The ablation procedure itself can be quite taxing to their hearts,” says Dr. Bonde. “In fact, there are a lot of patients who are turned down for this procedure because of their poor heart function. With ECMO, all of those patients become candidates for ablation. We can maximize their chances of survival and chances of success with the VT ablation.”
The first patient treated at Yale with the procedure was a man with “VT storm,” characterized by incessant life-threatening heart rhythms necessitating multiple repetitive shocks. The patient, who had already had two open heart operations, had been repetitively getting up to six consecutive shocks in less than one minute from his defibrillator, and Dr. Akar wanted to perform a radiofrequency catheter ablation to pinpoint the source of the problem and burn it.
The physicians performed what they say is typically a 4- to 6-hour procedure with a team of about 15 people, including surgeons, electrophysiologists, nurses, perfusionists, technologists and others. Dr. Akar was pleased that the ECMO support allowed him to take the time he needed to perform the ablation procedure carefully. Most importantly, he says, ECMO allowed him to induce the dangerous heart rhythm long enough for him to locate its source.
“The VT procedure is potentially long and technically complicated. Many patients have such severe underlying heart disease that they would really be unable to withstand the stress of this procedure if it wasn’t for the hemodynamic support provided by the ECMO,” says Dr. Akar.
Dr. Bonde says the development of Yale’s adult ECMO program in the past year as a temporary measure for patients with adult respiratory distress syndrome, acute heart failures, cath lab emergencies and other serious events laid the foundation for the successful hybrid procedures.
“We’ve matured the adult ECMO program and are having very good outcomes, and this procedure is an extension of that,” he says. “We waited until now to do it because we wanted to make sure the team is confident and complex procedures such as VT ablation can be supported with ease.”
Other centers in the country have offered the hybrid procedure, either with ECMO or using pumps that take over the function of the heart, but not the lungs. “This is the first such case at Yale and to my knowledge in Connecticut,” Dr. Akar says. “I look forward to offering this important therapy as we build our ECMO and VT programs to treat sicker individuals.”
The two doctors predict Yale will treat at least 20 to 30 patients next year with the hybrid procedure and more as patients and referring physicians learn the procedure is available.