Catheter ablation

Catheter ablation refers to the use of catheters to “burn” (with radiofrequency) or “freeze” (with cryoablation) a part of the heart, with the goal of treating a tachyarrhythmia. The catheter is inserted by the Seldinger technique into a vein (like the femoral vein) and directed toward the heart. Once the catheter is in the heart the electrodes on the tip can be used to detect the area which is responsible for the arrhythmia, after which the same catheter can be used to ablate the area.

Classically (in the 90s), catheter ablation could only be performed in conditions where the culprit was a well-defined anatomical area. Nowadays, modern electrophysiology labs can use modern techniques like 3D mapping to locate and treat arrhythmias with more complex pathomechanisms.

Nowadays, catheter ablation can be used for:

• Most paroxysmal supraventricular tachycardias (AVNRT, AVRT)
• Wolff-Parkinson White syndrome
• Atrial flutter (both typical and atypical)
• Atrial fibrillation
• Monomorphic ventricular tachycardia
• Ventricular fibrillation induced by unifocal premature ventricular beats

For the first two + typical atrial flutter, the cure rate is very high and so catheter ablation is often the first choice compared to pharmacological therapy. Typical atrial flutter originates from a reentry circuit loop in a well-defined anatomical area (the cavotricuspid isthmus), making it an easy target for ablation. Atypical atrial flutter does not occur from a clearly defined area and is more difficult but not impossible to treat.

Atrial fibrillation often originates from or is propagated by myocardium near the pulmonary veins. Pulmonary vein (electrical) isolation, achieved by creating scar tissue around the pulmonary veins with the use of ablation, leads to symptom relief in 60 – 70%.