Late atrial tachycardia following pulmonary vein isolation: Analysis of successful discrete ablation sites

BackgroundThe role of additional left atrial linear lesions performed during pulmonary vein isolation (PVI) to prevent atrial tachycardias (ATs) is not yet clear.ObjectiveTo analyse successful ablation sites of late-onset post-PVI AT, and to understand whether additional ablation lines at mitral isthmus and left atrium (LA) roof could have been useful in preventing these jatrogenic ATs.MethodsFrom March, 2002 to August, 2008, 366 patients underwent PVI alone for drug-refractory atrial fibrillation (AF). Twenty-six (7.1%) of these patients developed late AT during follow-up, and were referred for ablation. Successful discrete ablation sites were analysed. In no patient the index AT was terminated by a linear lesion in mitral isthmus or LA roof.ResultsTwenty-seven ATs were mapped; mean CL was 261 ± 71.6 ms. In 3/26 patients (11.5%), mapping was unsuccessful, while 23/26 (88.5%) patients underwent a successful procedure (24 AT morphologies in 23 patients - 3/24 were mapped as mitral isthmus, and 1/24, as LA roof-dependent AT).Among the 24 successfully mapped ATs, 17/24 (70.8%) displayed a macroreentrant activation and the remaining 7/24 (29.1%), a focal pattern.Finally, in 22/26 (84.6%) patients, ATs were no more inducible. At a mean f/u of 22.4 ± 12.2 months, 23/26 (88.4%) patients remained AT-free (antiarrhythmic drugs prescribed in 5/26, 19.2% patients for AF prevention).ConclusionsIn our case series, less than one-fifth of late-onset post-PVI ATs were mapped as mitral isthmus- or LA roof-dependent circuits.