A. Gavin

Pulmonary venous isolation versus additional substrate modification as treatment for paroxysmal atrial fibrillation

BackgroundPulmonary vein isolation alone is ineffective in maintaining sinus rhythm in up to one third of patients with paroxysmal atrial fibrillation (AF). We compared pulmonary vein antral isolation plus additional limited ablation along the inferoposterior left atrium and epicardially within the adjacent coronary sinus (PVAI + CS) to pulmonary vein antral isolation (PVAI) alone in patients with paroxysmal AF.MethodsForty-two consecutive patients with paroxysmal AF were prospectively randomized to PVAI vs. PVAI + CS. All patients were seen 3, 6, 12, and 18xa0months after ablation and underwent 24-h ambulatory Holter monitoring.ResultsFollowing a single procedure, 17 out of 22 patients (77%) remained arrhythmia free off antiarrhythmic medication after PVAI at 18xa0months vs. 10 out of 20 (50%) after PVAI + CS (pu2009<u20090.01). After PVAI, three patients had recurrent paroxysmal AF, and two had atrial tachycardia, whereas after PVAI + CS, three patients had recurrent paroxysmal AF, and seven had atrial tachycardia. All patients in the PVAI + CS group with atrial tachycardia who underwent a second procedure were found to have peri-mitral macro-reentry as the underlying mechanism. Eighty-one percent of patients remained arrhythmia free off medication after 1.09 procedures in the PVAI group vs. 80% after 1.35 procedures in the PVAI + CS group (pu2009<u20090.01).ConclusionThe addition of limited ablation along the inferoposterior left atrium and within the adjacent coronary sinus to PVAI alone did not reduce the recurrence rate of paroxysmal atrial fibrillation and was associated with an increased rate of peri-mitral macro-reentrant atrial tachycardia.

Assessment of oesophageal position by direct visualization with luminal contrast compared with segmentation from pre-acquired computed tomography scan—implications for ablation strategy

AIMSnAtrio-oesophageal fistula is a rare but often fatal complication of catheter ablation for atrial fibrillation (AF). Various strategies are employed to evaluate the oesophageal position in relation to the posterior left atrium (LA). These include segmentation of the oesophagus from a pre-acquired computed tomography (CT) scan and direct, real-time assessment of the oesophageal position using contrast at the time of the procedure.nnnMETHODS AND RESULTSnOne hundred and fourteen patients with drug-refractory AF underwent CT scanning prior to AF ablation. The LA and oesophagus were segmented from this scan. The oesophagus was deemed midline, ostial if it crossed directly behind any of the pulmonary vein (PV) ostia, or antral if it passed within 5 mm of a PV ostium. Under general anaesthesia at the time of ablation, the same patients were administered contrast via an oro-gastric tube to outline the oesophagus. Catheters were placed at the PV ostia and oesophageal position in relation to the PVs was established radiographically using a postero-anterior view. Oesophageal position assessed by real-time assessment correlated with the CT scan in only 59% of patients. In 34% the oesophagus was more right sided on direct visualization, while in 7% it was more left sided.nnnCONCLUSIONnSegmentation of the oesophagus from the CT scan did not correlate the real-time oesophageal position at the time of the procedure in over 40% of patients under general anaesthesia. Reliance on the determination of oesophageal position by previously acquired CT may be misleading at best and provide a false sense of security when ablating in the posterior LA.

Brugada ECG Pattern Unmasked by IV Flecainide in an Individual with Idiopathic Fascicular Ventricular Tachycardia

A 45-year old man presents with stable monomorphic ventricular tachycardia. He had previously been diagnosed with idiopathic fascicular ventricular tachycardia. Intravenous flecainide results in termination of his tachycardia but unmasks a latent type 1 Brugada ECG pattern not seen on his resting ECG. We discuss his subsequent management and the need to consider an alternative diagnosis in individuals with a Brugada type ECG pattern who present with stable monomorphic ventricular tachycardia.