Electrophysiological characterization and efficacy of radiofrequency ablation of focal atrial tachycardia originating from the left atrial appendage / 中华心血管病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To analyze the electrophysiological characteristics and efficacy of radiofrequency catheter ablation (RFA) of focal atrial tachycardia (AT) originating from the left atrial appendage (LAA).</p><p><b>METHODS</b>Electrophysiologic study and RFA were performed in 9 patients (4 female) with focal AT originating from the LAA. Atrial appendage angiography was performed to identify the origin of AT. P waves were classified as negative, positive, isoelectric, or biphasic.</p><p><b>RESULTS</b>The mean age was (21 +/- 9) years. AT occurred spontaneously or was induced by isoproterenol infusion rather than programmed extrastimulation and burst atrial pacing. A characteristic P-wave morphology and endocardial activation pattern were observed. Positive P-wave in inferior leads was seen in all patients, upright or biphasic (+/-) component P wave was observed in lead V1, isoelectric component or an upright component P wave with low amplitude ( < 0.1 mV) was seen in lead V2-V6. Earliest endocardial activity occurred at the distal coronary sinus (CS) in all patients. The earliest endocardial activation at the successful RFA site occurred (36.7 +/- 7.9) ms before the onset of P wave. RFA was successful in all 9 patients immediately post procedure. AT reoccurred in 2 patients within 1 month post RFA and AT disappeared post the 2nd-RFA. AT reoccurred in 1 patient and terminated after the 3rd RFA. At the final follow-up (12 +/ 5) months, all 9 patients were free of arrhythmias without antiarrhythmic drugs.</p><p><b>CONCLUSIONS</b>The LAA is an uncommon site of origin for focal AT. The characteristic P wave and activation timing are suggestive for focal AT originating from the LAA. LAA focal ablation is safe and effective for patients with focal AT originating from the LAA.</p>