Evaluation of periesophageal nerve injury after pulmonary vein isolation using the (13)C-acetate breath test.

BACKGROUND: Pulmonary vein isolation (PVI) has become an important option for treating patients with atrial fibrillation (AF). Periesophageal nerve (PEN) injury after PVI causes pyloric spasms and gastric hypomotility. This study aimed to clarify the impact of PVI on gastric motility and assess the prevalence of gastric hypomotility after PVI. METHODS: Thirty consecutive patients with AF underwent PVI under luminal esophageal temperature (LET) monitoring. The (13)C-acetate breath test was conducted before and after the procedure for all patients (PVI group). Gastric emptying was evaluated using the time to peak concentration of (13)CO2 (T max). This test was also conducted in another 20 patients who underwent catheter ablation procedures other than PVI (control group). RESULTS: The number of patients with abnormal T max (≥75 min) increased from seven (23%) to 13 (43%) and from three (15%) to five (25%) after the procedure in the PVI group and control group, respectively. The mean T max was longer after PVI than before PVI (64±14 min vs. 57±15 min, p=0.006), whereas there was no significant difference before and after the procedure in the control group. However, no significant difference in ΔT max was observed between the two groups (p=0.27). No patients suffered from symptomatic gastric hypomotility. CONCLUSIONS: Asymptomatic gastric hypomotility occurred more often after PVI. However, the average impact of PVI on gastric motility was minimal.

Estimation of the origin of ventricular outflow tract arrhythmia using synthesized right-sided chest leads.

AIMS: For successful ablation of ventricular outflow tract arrhythmia, estimation of its origin prior to the procedure can be useful. Morphology and lead placement in the right thoracic area may be useful for this purpose. Electrocardiography using synthesized right-sided chest leads (Syn-V3R, Syn-V4R, and Syn-V5R) is performed using standard leads without any additional leads. This study evaluated the usefulness of synthesized right-sided chest leads in estimating the origin of ventricular outflow tract arrhythmia. METHODS AND RESULTS: This retrospective study included 63 patients in whom successful ablation of ventricular outflow tract arrhythmia was performed. Numbers of arrhythmias originating from the left ventricle, the septum of the right ventricle, and the free wall of the right ventricle were 11, 40, and 13, respectively. In one patient, two different left ventricular outflow tract origins were found. Electrocardiographic recordings from right-sided chest leads were divided into three types as follows: those in which an R > S concordance, a transitional zone, or an R < S concordance were detected. In all left arrhythmia cases, R > S concordance was observed. A transitional zone was evident in 34 of 40 cases of right ventricular outflow tract arrhythmia originating in the ventricular septum, and an R < S concordance was observed in 6 of the 40 cases. However, an R < S concordance was found in all cases of right ventricular outflow tract arrhythmia originating in the free wall. CONCLUSION: Synthesized right-sided chest lead electrocardiography may be useful for estimating the origin of ventricular outflow tract arrhythmia.

Identification of left atrial ganglionated plexi by dense epicardial mapping as ablation targets for the treatment of concomitant atrial fibrillation.

BACKGROUND: Autonomic ganglionated plexi (GPs) play a significant role in the initiation and maintenance of atrial fibrillation (AF). GPs are key targets for a maze procedure. The purpose of this study was to identify the location of the left atrial GPs based on dense epicardial mapping during a maze procedure in patients with concomitant AF. METHODS: Sixteen patients (age, 68 ± 10 years; 11 males, 69%) with heart failure and concomitant AF (duration 55 ± 86 months) underwent intraoperative epicardial electrophysiological mapping and a GP ablation using the maze procedure at our institution. Twenty-four-site, high-frequency stimulation (1,000/min; output, 18 V; pulse width, 0.75 ms) was performed by placing tweezers directly onto the potential GP sites on the left atrial epicardium. RESULTS: Active GPs were found in 13 (81%) of the 16 patients, and 12 (92%) of 13 patients had active GPs between the right pulmonary veins (PVs) and the interatrial groove. For those patients with active locations, a 7-day event-loop recording demonstrated that 12 (92%) of 13 patients were maintained in sinus rhythm 3 months after the operation. CONCLUSION: Dense epicardial mapping in the potential GP areas identified active GP locations in a high percentage of patients. GPs between the PVs and interatrial groove have a high potential as ablation targets for treatment of concomitant AF.