No abstract

No abstract

BackgroundThe clinical impact of a decrease in impedance during radiofrequency catheter ablation (RFCA) has not been fully clarified. The aim of the study was to analyze the impact of impedance decrease and to determine its optimal cutoff value during RFCA.MethodsWe evaluated 34 consecutive patients (total 3264 lesions, mean age 66 ± 8.7 years, 10 females) who underwent their first ablation for atrial fibrillation (AF). The impedance decrease, average contact force (CF), application time, force‐time integral (FTI), product of impedance decrease and application time (PIT), and the product of impedance decrease and FTI (PIFT) were measured for all lesions. Levels of cardiac troponin I (TrpI) were measured for assessment of myocardial injury. The incidence of intraprocedural pulmonary vein‐left atrium reconnection or dormant conduction (reconnection) was determined. The relationships between the ablation parameters and the increase in TrpI (ΔTrpI) were evaluated. The predictive value of the parameters for reconnection was assessed using receiver operating characteristic (ROC) curve analysis.ResultsReconnection was detected in 18 patients. Average FTI and PIT were significantly correlated with ΔTrpI (FTI: r 2 = .19, P = .0090, PIT: r 2 = .21, P = .0058). PIFT was correlated with ΔTrpI and was the best of the three indexes (PIFT: r 2 = .29, P = .0010). In ROC curve analysis, the area under the curve for predicting reconnection was 0.71 and the optimal cutoff value was 5200 for PIFT (sensitivity 78%, specificity 63%).ConclusionThe combination of CF and a decrease in impedance could be important in the evaluation of myocardial lesions and reconnection during RFCA.

No abstract

The need for lead extraction has been increasing with an increase in the demand for cardiac implantable electronic devices (CIEDs) in the aging general population [1][2][3]. The elderly population accounts for a significant proportion of those undergoing CIED implantations [4][5][6][7] thereby causing an increase in the number of cases of lead extraction in the elderly [8]. Considering the high mortality rates due to CIED infection without removal of the infected device in elderly patients [9], early removal of the infected CIEDs by lead extraction is mandatory for the management of the infection. Although the safety and effective-ness of laser-assisted lead extraction in elderly patients have been reported for the USA and European countries [10-13], there are a paucity of data for the Asian population. The Asian population presents lower body mass index (BMI) than Caucasians [14]; lower BMI is a known risk factor for major adverse events associated with lead extraction [15][16][17]. Therefore, the aim of this study was to determine whether the Japanese elderly population was at high risk for procedure-related complications and procedural failures following transvenous excimer laser-assisted lead extraction.