Utility of high density multielectrode mapping during ablation of scar-related ventricular tachycardia.

INTRODUCTION: Multielectrode mapping catheters (MEMC) allow the performance of high resolution and density maps but the utility of these catheters in ventricular tachycardia (VT) ablation procedures has not been yet widely described. We sought to evaluate the utility of a MEMC during scar-related VT ablation procedures. METHODS: Eighty-five consecutive scar-related VT ablation procedures were performed in 81 patients. In the first 26 procedures, a standard 3.5-mm tip linear catheter was employed for endocardial/epicardial mapping (control group). In the following 59 procedures mapping was performed with a MEMC (study group). Procedural time, LV endocardial and epicardial mapping time, complications and ablation outcomes were compared. RESULTS: The use of the MEMC resulted in a significant shortening of the endocardial and epicardial mapping times (38 ± 15 minutes vs. 56 ± 24 minutes for endocardial LV mapping in the study and control group, respectively, P = 0.001; and 28 ± 9 minutes vs 41 ± 16 minutes, for epicardial mapping, P = 0.011) as well as the total procedural time (177 ± 53 minutes vs. 206 ± 50 minutes, respectively, P = 0.02). The mapping density was also significantly increased in the study group (mean endocardial LV points: 2,143 ± 1,419 vs. 485 ± 174, for the study and control group, respectively, P < 0.0001), specially within the scar area (49.6 ± 34 points/cm2 vs. 8.4 ± 4.6 points/cm2 , P < 0.001). No differences in acute and long-term follow-up outcomes were observed. CONCLUSIONS: High-density multielectrode mapping is associated with a significant reduction of procedural and mapping times and a significant increase of mapping density without affecting outcomes in patients with scar-related VT.

Advanced Therapies for Ventricular Arrhythmias in Patients With Chagasic Cardiomyopathy: JACC State-of-the-Art Review.

Chagas disease is caused by infection from the protozoan parasite Trypanosoma cruzi. Although it is endemic to Latin America, global migration has led to an increased incidence of Chagas in Europe, Asia, Australia, and North America. Following acute infection, up to 30% of patients will develop chronic Chagas disease, with most patients developing Chagasic cardiomyopathy. Chronic Chagas cardiomyopathy is highly arrhythmogenic, with estimated annual rates of appropriate implantable cardioverter-defibrillator therapies and electrical storm of 25% and 9.1%, respectively. Managing arrhythmias in patients with Chagasic cardiomyopathy is a major challenge for the clinical electrophysiologist, requiring intimate knowledge of cardiac anatomy, advanced training, and expertise. Endocardial-epicardial mapping and ablation strategy is needed to treat arrhythmias in this patient population, owing to the suboptimal long-term success rate of endocardial mapping and ablation alone. We also describe innovative approaches to improve acute and long-term clinical outcomes in patients with refractory ventricular arrhythmias following catheter ablation, such as bilateral cervicothoracic sympathectomy and bilateral renal denervation, among others.

Trends in percutaneous pericardial access during catheter ablation of ventricular arrhythmias: a single-center experience.

PURPOSE: Percutaneous pericardial access (EpiAcc) assists ventricular tachycardia/premature ventricular complex (VT/PVC) ablation by permitting epicardial mapping and ablation outside the vicinity of the coronary venous system. We sought to determine whether expanding indications and growing operator experience have led to increased rates of EpiAcc. METHODS: We reviewed the frequency of EpiAcc procedures performed during VT/PVC ablation between 2007 and 2014 to identify temporal trends in the procedure. RESULTS: There were 758 patients undergoing 880 VT/PVC ablation procedures (average 95 patients per year; 110 procedures per year) during the study period. EpiAcc for ablation was utilized in 170 patients (181 procedures). The average age at the time of EpiAcc was 55 ± 16 years and 129 (76.0 %) patients were male. The rate of EpiAcc was 22.9 % in males and 15.4 % in females (P = 0.008). The absolute number of EpiAcc procedures increased from 2007 (6 procedures) to 2014 (27 procedures). Similarly, the proportion of patients undergoing EpiAcc increased from 8.6 % of procedures in 2007 to 24.5 % in 2014 (P < 0.0001). While EpiAcc use became more frequent, the rate of epicardial ablation among those who underwent EpiAcc remained stable (approximately 70 %). CONCLUSIONS: Percutaneous pericardial access has been used with increasing frequency as part of VT/PVC ablations without an increase in the rate of epicardial ablation. This growing utilization may lay the foundation for novel epicardial strategies as new technologies emerge. The frequency of percutaneous pericardial access in VT/PVC ablation appears to be greater in males, reasons for which are undefined.