An atypical atrial flutter of focal origin: a study using a noncontact mapping system

Mechanisms of Organized Left Atrial Tachycardias Occurring After Pulmonary Vein Isolation

BACKGROUND

A proarrhythmic consequence of pulmonary vein (PV) isolation can be a recurrent organized left atrial (LA) tachycardia after ablation. This arrhythmia is frequently referred to as "left atrial flutter," but the mechanism and best ablation strategy have not been determined.

METHODS AND RESULTS

Isolation of arrhythmogenic PVs was initially performed by segmental ostial PV ablation guided by a circular mapping catheter in 341 patients. Patients whose predominant recurrent arrhythmia was a persistent organized tachycardia returned for mapping and ablation. Recurrent organized LA tachycardias (cycle length 253+/-33 ms, range 213 to 328 ms) occurred in 10 (2.9%) of 341 patients (age 59+/-9 years, 1 woman). Mapping was consistent with a focal origin in 8 patients and with macroreentry in 1 patient and was unclear in 1 patient owing to degeneration to atrial fibrillation. Focal tachycardias originated from reconnected segments of prior isolated PVs (6 patients), the posterior LA (1 patient), or the superior septum (1 patient). Focal atrial tachycardias were ablated with point lesions that targeted the earliest activation. All reconnected PVs were also reisolated. Reentrant LA flutter occurred around the left PVs in 1 patient. After 6.7+/-2.3 months of follow-up, 9 (90%) of 10 patients were arrhythmia free (4 of whom were taking antiarrhythmic drug therapy), and one was having recurrent atrial fibrillation.

CONCLUSIONS

Recurrent organized LA tachycardia after PV isolation is uncommon and typically has a focal origin from reconnected PV ostia. Reisolation of the PV and ablation of non-PV foci are sufficient to treat this proarrhythmia. Linear lesions are only required when a macroreentrant mechanism is present.

Treatment of Sustained Left Atrial Tachycardia by Ostial Pulmonary Vein Isolation

This report describes two patients with sustained regular left atrial tachycardias originating from multiple pulmonary veins in the absence of clinical evidence of atrial fibrillation. The tachycardias were eliminated by activation map-guided pulmonary vein isolation. Stable sustained regular pulmonary vein tachycardias unassociated with atrial fibrillation are uncommon, and they belong to the spectrum of pulmonary vein arrhythmias that include the more common paroxysmal and unstable tachycardias engendering atrial fibrillation.