A randomized-controlled pilot study comparing ICD implantation with and without intraoperative defibrillation testing in patients with heart failure and severe left ventricular dysfunction: a substudy of the RAFT trial.

INTRODUCTION: The need to perform defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion is controversial. In the absence of randomized trials, some regions now perform more than half of ICD implants without DT. METHODS: During the last year of enrolment in the Resynchronization for Ambulatory Heart Failure Trial, a substudy randomized patients to ICD implantation with versus without DT. RESULTS: Among 252 patients screened, 145 were enrolled; 75 randomized to DT and 70 to no DT. Patients were similar in terms of age (65.9 ± 9.3 years vs 67.9 ± 8.9 years); LVEF (24.7 ± 4.6% vs 23.6 ± 4.6%), QRS width (154.8 ± 23.5 vs 155.8 ± 23.6 ms), and history of atrial fibrillation (5% vs 6%). All 68 patients in the DT arm tested according to the protocol achieved a successful DT (≤25 J); 96% without requiring any system modification. No patient experienced perioperative stroke, myocardial infarction, heart failure (HF), intubation or unplanned ICU stay. The length of hospital stay was not prolonged in the DT group: 20.2 ± 26.3 hours versus 21.3 ± 23.0 hours, P = 0.79. One patient in the DT arm had a failed appropriate shock and no patient suffered an arrhythmic death. The composite of HF hospitalization or all-cause mortality occurred in 10% of patients in the no-DT arm and 19% of patients in the DT arm (HR = 0.53, 95% CI: 0.21-1.31, P = 0.14). CONCLUSIONS: In this randomized trial, perioperative complications, failed appropriate shocks, and arrhythmic death were all uncommon regardless of DT. There was a nonsignificant increase in the risk of death or HF hospitalization with DT.

Remote magnetic navigation-assisted catheter ablation enhances catheter stability and ablation success with lower catheter temperatures.

BACKGROUND: It has been suggested that remote magnetic navigation (RMN) may provide enhanced catheter stability and substrate contact to aid in ablation. To date, no study has examined this claim. Accordingly, we compared the characteristics of the successful ablation of atrioventricular reentry tachycardia (AVNRT) using RMN with a matched population ablated using a conventional (CON) manual approach. METHODS: Sixteen patients who underwent RMN-assisted ablation of typical AVNRT were matched with 16 patients who had a CON-AVNRT ablation. RESULTS: All patients had successful slow pathway modification without complication. The mean catheter temperature achieved with the successful ablation was significantly lower with RMN than with CON (42 +/- 7 degrees C vs 47 +/- 3 degrees C, P

Feasibility study of endocardial mapping of ganglionated plexuses during catheter ablation of atrial fibrillation.

BACKGROUND: Numerous reports have demonstrated an association between autonomic tone and atrial fibrillation (AF). Pulmonary vein (PV) denervation during catheter ablation of AF has been shown to significantly reduce recurrence of AF. OBJECTIVES: The purpose of this study was to assess the safety and efficacy of high-frequency stimulation at mapping cardiac ganglionated plexuses in patients undergoing catheter ablation of AF. METHODS: Fourteen patients with a history of symptomatic AF underwent a single transseptal approach and electroanatomic mapping of the left atrium, right atrium, and coronary sinus. Using high-frequency stimulation with patients under general anesthesia (20-50 Hz, 5-15 V, pulse width 10 ms), mapping of ganglionated plexuses was performed. Radiofrequency (RF) ablation was performed during AF guided by complex fractionated atrial electrograms. Lesions were mostly delivered circumferentially in the antral area of the PVs, predominantly over and adjacent to regions of ganglionated plexuses. RESULTS: There was a mean of 4 +/- 1 (range 2-6) ganglionated plexuses per patient, and a mean total of 3 +/- 1 RF applications were delivered over positive vagal sites. Although a vagal response occurred infrequently during ablation (0.9%), postablation high-frequency stimulation failed to provoke a vagal response in 30 (88%) of 34 previously positive vagal sites that underwent ablation. CONCLUSION: Ganglionated plexuses can be precisely mapped using high-frequency stimulation and are located predominantly in the path of lesions delivered during ablation of AF. Objective documentation of modification of autonomic tone can be documented in the majority of patients. Future studies are required to determine the specific role of mapping and targeting of ganglionated plexuses in patients undergoing catheter ablation of AF.

Acupuncture triggering inappropriate ICD shocks.

Acupuncture is a modality of alternative medicine popular certain sectors of society. The possible interaction between acupuncture and ICD therapy has not been previously investigated. A case of acupuncture triggering inappropriate shocks from the ICD is reported.