Classification of A-fib and hybrid ablation as a treatment for persistent A-fib
Hybrid ablation is used as treatment for long-standing persistent atrial fibrillation (A-fib), the most severe form of the condition affecting about 45% of A-fib patients. Steven M. Peterson, M.D., cardiothoracic surgeon with Norton Heart & Vascular Institute Structural Heart Program, gave a clinical case review of a hybrid ablation procedure. He was joined by Kent E. Morris, M.D., cardiologist and electrophysiologist with Norton Heart & Vascular Institute.
Paroxysmal atrial fibrillation is defined as self-limiting and typically less than seven days. Patients convert spontaneously back to normal rhythm. Persistent atrial fibrillation is atrial fibrillation that lasts longer than seven days, or requires some sort of intervention to restore normal sinus rhythm. Long-standing persistent atrial fibrillation is defined as continuous atrial fibrillation for greater than one year in duration.
Hybrid ablation treats A-fib in procedures that combine endocardial radiofrequency ablation with epicardial ablation. The ablations create lesions that interrupt the faulty electrical signals that cause A-fib.
A-fib typically starts at the base of the pulmonary veins, on the posterior heart wall or in the left atrial appendage, and can cause symptoms such as palpitations, a fluttering feeling in the chest and arrhythmia.
Long-standing persistent A-fib can cause shortness of breath, dizziness, weakness, fatigue, low blood pressure and pain or pressure in the chest. A-fib increases risk of stroke, heart failure, dementia, chronic fatigue, decreased activity level and quality of life decline.
Hybrid cardiac ablation
The first step in a hybrid ablation is a minimally invasive pericardioscopic epicardial ablation that applies radiofrequency energy to the posterior left atrial wall, distal from the esophagus. The aim is to create durable and contiguous lesions while reducing risk of injury to the adjacent heart structures.
The EPi-Sense device is cooled on the back side with saline solution to prevent injury to healthy tissue. On the underside, vacuum pressure pulls heart tissue into the radiofrequency coil while perfusion conducts energy downward into tissue while circulating blood absorbs excess heat.
The second stage is an endocardial ablation that uses mapping and ablation to target the regions that need additional treatment and any areas impeded by pericardial reflections during the epicardial part of the treatment. This part of the procedure is a conventional cardiac ablation achieved with a catheter.
A study of 153 patients at 27 centers found that compared with endocardial ablation alone:
- Patients were twice as likely to no longer need A-fib medication.
- After one year, patients spent 90% less time in A-fib.
Norton Heart & Vascular Institute has been performing hybrid ablations for paroxysmal A-fib (occasional episodes that last up to seven days) and persistent A-fib (episodes that last beyond seven days for as long as a year) since 2017.
View Dr. Peterson’s and Dr. Morris’s clinical case review in its entirety here.