Background-Radiofrequency ablation for atrial fibrillation is becoming widely practiced. Methods and Results-Two patients undergoing circumferential pulmonary vein ablation for atrial fibrillation in different centers developed symptoms compatible with endocarditis 3 to 5 days after the procedure. Their clinical condition deteriorated rapidly, and both suffered multiple gaseous and/or septic embolic events causing cerebral and myocardial damage. One patient survived after emergency cardiac and esophageal surgery; the other died of extensive systemic embolization. An atrio-esophageal fistula was identified in both patients. Conclusions-Atrio-esophageal fistulas can occur after catheter ablation in the posterior wall of the left atrium. This diagnosis should be excluded in any patient with symptoms or signs of endocarditis after left atrial ablation, and expeditious cardiac surgery is critical if the diagnosis is confirmed. Lower power and temperature settings for applications of radiofrequency energy along the posterior left atrial wall may prevent further cases of fistula formation.

Background-There are no data to evaluate the relationship between autonomic nerve function modification and recurrent atrial fibrillation (AF) after circumferential pulmonary vein ablation (CPVA). This study assesses the incremental benefit of vagal denervation by radiofrequency in preventing recurrent AF in a large series of patients undergoing CPVA for paroxysmal AF. Methods and Results-Data were collected on 297 patients undergoing CPVA for paroxysmal AF. Abolition of all evoked vagal reflexes around all pulmonary vein ostia was defined as complete vagal denervation (CVD) and was obtained in 34.3% of patients. Follow-up ended at 12 months. Heart rate variability attenuation, consistent with vagal withdrawal, was detectable for up to 3 months after CPVA, particularly in patients with reflexes and CVD, who were less likely to have recurrent AF than those without reflexes (Pϭ0.0002, log-rank test). Only the percentage area of left atrial isolation and CVD were predictors of AF recurrence after CPVA (PϽ0.001 and Pϭ0.025, respectively). Conclusions-This study suggests that adjunctive CVD during CPVA significantly reduces recurrence of AF at 12 months.

In asymptomatic, high-risk children with the Wolff-Parkinson-White syndrome, prophylactic catheter ablation performed by an experienced operator reduces the risk of life-threatening arrhythmias.

Aiming to image NTS1 overexpressing tumors, the diarylpyrazole glycoconjugate 8, derived from the potent NTS1 antagonist SR142948A, was synthesized taking advantage of the palladium-catalyzed aminocarbonylation reaction. The glycoconjugate 8 displayed excellent affinity and selectivity toward NTS1. Radiosynthesis proceeded straightforwardly, obtaining [(18)F]8 with excellent stability and highly beneficial biodistribution in vivo as demonstrated by PET imaging in HT29 tumor-bearing nude mice. Thus, the tracer [(18)F]8 represents a highly promising candidate for PET imaging of NTS1-positive tumors.