The curative catheter ablation of atrial fibrillation (AF) has made some important advances during the last few years towards a reproducible and effective procedure. Besides the role of the electrical trigger to induce paroxysmal AF episodes by rapid bursts from within the pulmonary veins (PVs), invasive electrophysiology (EP) studies also demonstrate the importance of the atrial myocardium in sustaining the AF.

To overcome some of the shortcomings of the conventionally used sequential “point-by-point” radiofrequency ablation, new energy sources such as laser, ultrasound, and cryothermia are currently under investigation. These apply “single shot” lesions via balloon mounted catheters positioned at the PV ostia. Other new tools, such as the magnetic navigation system, allow complete remote controlled mapping (and ablation) by combining both three dimensional (3D) steering and 3D mapping/imaging in a single system. All these devices and technologies still have to prove their effectiveness and their ability to meet high expectations.

Finally, recent efforts have focused on reproducible ablation strategies for chronic long lasting AF, where elimination of the PV trigger might not be enough to maintain sinus rhythm (SR).

RATIONALE FOR TARGETING THE PULMONARY VEINS

The role of the PVs as the major sites of induction of AF was identified during the attempt to replicate the surgical approach of compartmentalisation by linear incisions (Cox’s maze operation).1 During these initial ablation procedures, repetitive initiating extrasystoles from within the PVs were demonstrated and subsequently eliminated by direct ablation. Although this observation had been made also by other investigators, the role of the PV as the dominant site of AF induction only then came to full recognition. These high frequency triggers can induce AF, and the activity of the trigger itself may explain the amount and duration of the induced AF episodes. But the remodelling processes soon change the properties of the atrial myocardium to sustain the once …