Radiofrequency ablation is a procedure that enables the treatment of many types of rapid heart beat (tachycardia). A special catheter (ablation catheter) is introduced into the heart and positioned over a small area of the heart muscle responsible for the occurrence of irregular heart beats (arrhythmia). The ablation catheters is able to deliver radiofrequency energy (frequency 300-500 kHz, energy 10-50 watts, duration varies for each separate application). Radiofrequency energy thereby causes permanent micro-damage to the tissue with heat. Thus, damaged tissue is no longer able to produce the impulses responsible for arrhythmia or significantly reduces their occurrence. This method enables the patient to be permanently cured in some types of arrhythmia.
What types of arrhythmia can be treated with catheter radiofrequency ablation?
Paroxysmal supraventricular tachycardia (PSVT), including:
- Wolf-Parkinson-White Syndrome (WPW Syndrome) or atrioventricular re-entry tachycardia (AVRT)
- Atrioventricular nodal re-entry tachycardia (AVNRT)
- Atrial tachycardia (AT)
- Atrial flutter (AFl)
Atrial Fibrillation (AF)
Ventricular tachycardia (VT) and ventricular premature beats (known as extrasystoles – VES)
Some days before the procedure, it is necessary to stop taking certain medications in agreement with the cardiologist-electrophysiologist (anti-clotting drugs, some antiarrhythmic drugs). Consult with your doctor about stopping taking some medication a few days before your scheduled procedure, unless you have been told otherwise.
RF ablation is a therapeutic procedure that usually continues after a diagnostic electrophysiology study (see Cardiac electrophysiology study). Prior RF ablation starts, the patient may receive a venous sedative and/or painkiller. The use of RF energy generally does not cause pain, but chest discomfort or burning sensation may occur, which disappears after RF energy delivery stops and/or after medication administration.
Cardiac electrophysiology study
The ablation catheter is introduced into the heart usually through the femoral vein or artery to the heart. Afterwards, the same electrode locates the origin of arrhythmia (so-called mapping) and delivers RF energy.
At the end of the procedure, the doctor tries to cause the arrhythmia again, and if the arrhythmia is not provoked, the procedure ends. However, if arrhythmia is again triggered, the use of RF energy is repeated.
The duration of the procedure varies from patient to patient, depending on the arrhythmia involved. Typically, the procedure lasts two or more hours.
Upon completion of the EP procedure the catheters are removed and bleeding is stopped by briefly pressing the blood vessels through which the electrodes were placed. After bleeding is stopped, the puncture areas are covered with sterile bandages and the patient is returned to the ward lying down. Depending on the type arrhythmia involved, whether the veins or arteries were punctured, it is necessary to rest in bed for 6-24 hours after the procedure in order to prevent the bleeding of puncture site. Sandbags are sometimes placed on the puncture sites, which further exert pressure and prevent bleeding. During this time, toilet, feeding and hygiene are provided in the bed.
Patients may experience fatigue after RF ablation due to the use of sedatives and painkillers.
RF ablation complications. Complications of RF ablation are very rare and vary with different procedures. The figures are total including also complex procedures.
- puncture site complications, cardiovascular access: bleeding, haematoma, infection, embolism, pseudo-aneurysm, arteriovenous fistula, vascular perforation: 2-4%
- mechanical injuries of the heart (with catheter): cardiac perforation, tamponade, pericardial effusion, valvular injury, coronary sinus injury, myocardial infarction: 1-2%
- systemic thromboembolism, including stroke, and/or pulmonary embolism (<1%)
- pulmonary hypertension after atrial fibrillation ablation due to pulmonary vein stenosis
- phrenic nerve injury in sinus node modification or RF ablation of atrial fibrillation
- oesophageoatrial (between oesophagus and left atrium) fistula after AF ablation: 0.01-2%
- impulse conduction disorders in any part of the cardiac conduction system: AV blocks 1-3%
- the appearance of new arrhythmias
- death: about 0.1-0.3%