Transthoracic epicardial ablation of mitral isthmus for treatment of recurrent perimitral flutter

• Published in: Heart rhythm Vol. 11; no. 1; pp. 26 - 33
• Main Authors: Berruezo, Antonio, Bisbal, Felipe, Fernández-Armenta, Juan, Calvo, Naiara, Ángel Cabrera, José, Sanchez-Quintana, Damián, Andreu, David, de Caralt, Teresa M., Brugada, Josep, Mont, Lluís
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2014
• Subjects: Adult; Atrial Flutter - diagnosis; Atrial Flutter - physiopathology; Atrial Flutter - surgery; Cardiovascular; Catheter ablation; Catheter Ablation - methods; Echocardiography, Transesophageal; Electrophysiologic Techniques, Cardiac; Follow-Up Studies; Heart Conduction System - physiopathology; Heart Conduction System - surgery; Humans; Male; Middle Aged; Mitral isthmus line; Mitral Valve; Pericardium - surgery; Perimitral flutter; Recurrence; Thoracoscopy - methods; Time Factors; Tomography, X-Ray Computed; Transthoracic epicardial approach; Treatment Outcome; Transthoracic epicardial approach; PVI; TTE; AF; PV; Catheter ablation; PMF; IQR; CS; LMWH; Mitral isthmus line; RF; Perimitral flutter; MI; LAT; radiofrequency; mitral isthmus; interquartile range; left atrial tachycardia; atrial fibrillation; low-molecular-weight heparin; transthoracic epicardial; pulmonary vein isolation; coronary sinus; perimitral flutter; pulmonary vein
• ISSN: 1547-5271; 1556-3871; 1556-3871
• DOI: 10.1016/j.hrthm.2013.10.030

Perimitral flutter (PMF) is a common form of left atrial tachycardia after atrial fibrillation (AF) ablation. The mitral isthmus (MI) is the standard ablation target. However, in some cases bidirectional block cannot be achieved. The purpose of this study was to describe the first experience using a transthoracic epicardial (TTE) approach to treat recurrent PMF after prior unsuccessful ablation. This is a case series of four patients with recurrence of highly symptomatic drug-refractory PMF (all male, median age 55 years, 3/4 hypertensive, 2/4 persistent AF, median AF period 24 months). Three patients presented with PMF-related tachymyocardiopathy. TTE ablation of MI was performed after a median of two prior endocardial MI and coronary sinus ablation attempts, using an open-tip 3.5-mm irrigated catheter (40 W, 45ºC). Persistent bidirectional block was assessed by activation mapping and differential pacing and was achieved in all patients. No PMF recurrence was observed after median follow-up of 18 months (range 15–22 months; two patients without antiarrhythmic drugs and two with previously ineffective amiodarone). Left ventricular function normalized in all three patients with tachycardiomyopathy. There were no complications related to TTE approach. The present study is the first to report the feasibility of a TTE approach for highly symptomatic PMF refractory to endocardial and coronary sinus MI ablation.