Esophageal thermal lesions in radiofrequency ablation for atrial fibrillation: A prospective comparative study of thermal sensors.

BACKGROUND: Esophageal thermal lesion (ETL) is a complication of radiofrequency ablation for atrial fibrillation (RFAF). To prospectively compare the incidence of ETL, we used two linear, five- and three-sensor esophageal thermal monitoring catheters (ETMC5 and ETMC3). We also evaluated the predictors of ETL. METHODS: Patients receiving their first RFAF (n = 106) were randomized into two groups, ETMC5 (n = 52) and ETMC3 (n = 54). Ablation was followed by esophagogastroduodenoscopy within 3 days. RESULTS: Esophageal thermal lesion was detected in 7/106 (6.6%) patients (ETMC5: 3/52 [5.8%] vs. ETMC3: 4/54 [7.4%]; p = 1.0). The maximum temperature and number of measurements > 39.0°C did not differ between the groups (ETMC5: 40.5°C and 5.4 vs. ETMC3: 40.6°C and 4.9; p = .83 and p = .58, respectively). In ETMC5 group, the catheter had to be moved significantly less often (0.12 vs. 0.42; p = .0014) and fluoroscopy time was significantly shorter (79.2 min vs. 101.7 min; p = .0038) compared with ECMC3 group. The total number of ablations in ETMC5 group was significantly greater (50.2 vs. 37.7; p = .030) and ablation time was significantly longer (52.1 min vs. 40.1 min; p = .0039). Only body mass index (BMI) was significantly different between patients with and without ETL (21.4 ± 2.5 vs. 24.3 ± 3.4; p = .022). CONCLUSIONS: The incidence of ETL was comparable between ETMC5 and ETMC3 groups; however, fluoroscopy time, total ablation time, and total number of ablations differed significantly. Lower BMI may increase the risk of developing ETL.

Clinical predictors for bradycardia and supraventricular tachycardia necessitating therapy in patients with unexplained syncope monitored by insertable cardiac monitor.

BACKGROUND: Insertable cardiac monitors (ICMs) improve diagnostic yield in patients with unexplained syncope. The most of cardiac syncope is arrhythmic causes include paroxysmal bradycardia and supraventricular tachycardia (SVT) in patients with unexplained syncope receiving ICM. Predictors for bradycardia and SVT that necessitate therapy in patients with unexplained syncope are not well known. HYPOTHESIS: This study aimed to investigate predictors of bradycardia and SVT necessitating therapy in patients with unexplained syncope receiving ICMs. METHODS: We retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope. We performed Cox's stepwise logistic regression analysis to identify significant independent predictors for bradycardia and SVT. RESULTS: One hundred thirty-two patients received ICMs to monitor unexplained syncope. During the 17-month follow-up period, 19 patients (14%) needed pacemaker therapy for bradycardia; 8 patients (6%) received catheter ablation for SVT. The total estimated diagnostic rates were 34% and 48% at 1 and 2 years, respectively. Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p = .02) was an independent predictor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p = .008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p = .006) were identified as significant independent predictors for SVT. CONCLUSION: Syncope during effort, and palpitations or history of atrial fibrillation were independent predictors for bradycardia and for SVT. ICMs are useful devices for diagnosing unexplained syncope.