For several conditions of the heart causing irregular heart beat or a faster heart rate, catheter ablation has become the treatment of choice. The commonest type of catheter ablation is also called Radiofrequency Ablation or RFA.
In a nutshell, catheter ablation uses a form of energy that selectively targets the heart tissue causing the heart rhythm problem and makes it inactive. This puts an end to the arrhythmia that originated from the culprit site.
In many ways the heart is like a sophisticated pump that requires electrical impulse and wiring for its proper working. This electrical supply in the heart flows through specific tissues in a regular and measured fashion, ensuring seamless working of the heart’s pump. However, in many instances, this electrical flow can get blocked or travel repeatedly though the same tissue causing a kind of ‘short circuit’ in the overall wiring system of the heart. At other times, an abnormal tissue, which should not have been there, can cause extra generation of an electric impulse. Both of these problems end up causing irregular heartbeat, skipped beats or fast heart rates – all of which may have serious effects in the long run. Some medicines do help but may not be fully effective. Some cause serious side effects especially when taken for a longer period. The most effective way of tackling these rhythm problems is to destroy the tissue housing the abnormal electric circuitry responsible for the arrhythmia. This process of eliminating the abnormal tissue is called Ablation, and the commonest type is Radiofrequency Ablation (RFA). For many arrhythmias, RFA is curative in 90-98% of cases.
With the current technology, this highly skilled and complex procedure does not even require any major operation or opening of the chest wall. It is rather performed in a similar manner as an Angiography and Angioplasty. In brief, the process consists of inserting long thin tubes, called catheters, through one of the blood vessels reaching the heart. Mostly this is done under local anesthesia through the top of the leg, but sometimes through neck or from near the collar bone as well. Once the catheters are inside the heart, they are used to measure and map the electrical signals within different parts of the heart. This is done with the help of Fluoroscopy (X-Ray) machine and sophisticated Electrophysiology (EP) systems. Many times the cardiologist could also make the heart go racing the way it did during the symptomatic episode to help identify the location of the abnormal wiring. Once the abnormal tissue (wire) is localized another catheter called Ablation Catheter is inserted into the heart through the same route and positioned over the abnormal tissue. The tip of this catheter, when turned on, emits radiofrequency energy which cauterizes or burns the abnormal tissue in a localized manner. As mentioned before, the success rate of the procedure for most of the common arrhythmias is between 90-98%. Usually the procedure lasts for 1-3 hours and the patients can walk the same day. They can be discharged later, on the same day or the next day.
The common arrhythmias treated by RFA are:
- Supraventricular Tachycardia (SVT) – like WPW, AVRT, AVNRT, Atrial Tachycardia
- Atrial Flutter
- Atrial Fibrillation
- Ventricular Tachycardia
- Ventricular Premature Beats
The writer, Prof. (Dr.) Vivek Chaturvedi, is a Senior Consultant Cardiology & Director – Narayana Superspeciality Hospital in Gurugram.