Our approach to the ablation of atrioventricular nodal
reciprocating tachycardia (AVNRT), the most common
supraventricular tachycardia, is as follows: We first attempt ablation in the right atrial posteroseptum anterior to the coronary sinus ostium with a 4-mm non-irrigated tip
catheter. If ablation within the triangle of Koch is unsuccessful with radiofrequency (RF), we switch to
cryoablation and target a more superior (mid septal) region. We also utilize
cryoablation if RF ablation produces transient VA block (absence of retrograde conduction during junctional rhythm) or a fast junctional rhythm (<350 msec). If
cryoablation were to fail, or is not available, we would then suggest ablation within the coronary sinus targeting the roof (2-4 cm from the os) using a 3.5-mm irrigated tip
catheter. If
tachycardia were still inducible despite these measures, we would then proceed with transseptal
puncture (given our greater experience with this over a retrograde aortic approach) and perform RF ablation along the posteroseptal left atrium and inferoseptal mitral annulus utilizing an irrigated tip
catheter. In our experience,
cryoablation reliably results in elimination of the slow pathway. The only left atrial ablation for AVNRT at our institution in the past year was performed because a
patent foramen ovale allowed for rapid left atrial access, facilitating left atrial ablation of the slow pathway.