Catheter ablation of the parahisian accessory pathways from the aortic cusps-Experience of 20 cases-Improving the mapping strategy for better results.

INTRODUCTION: Catheter ablation of the parahisian accessory pathways (PHAP) has been established as the definitive therapy for this type of arrhythmia. However, the PHAP proximity to the normal atrioventricular conduction system makes the procedure technically challenging. Here, we have reported a case series of 20 patients with PHAP who underwent aortic access ablation to evaluate the safety and efficacy of this approach in the PHAP ablation. METHODS AND RESULTS: The ablation through the aortic cusps was the successful approach in 13 of 20 (65%) of the cases. In 11 patients, the aortic approach was the initial strategy for ablation, and the accessory pathway was eliminated in seven (63.6%) of them. The aortic approach followed a failed right-sided attempt in nine patients. In six (66.7%) patients, the ablation was successful with the aortic approach. The only independent predictor for the successful ablation with each approach was the earliest ventricular activation before delta wave (predelta time) and a right-sided earliest ventricular activation of more than 23 ms had high sensitivity and specificity for right-sided success. Systematically using the two strategies (right and left approaches), the ablation of the PHAP was successful in 18 (90%) patients. CONCLUSION: The aortic approach seems to be a safe and effective strategy for the ablation of PHAP. It can be used when the right-sided approach fails or even considered as an initial strategy when the predelta time is less than 23 ms in the right septal region. When combining the right- and left-sided approaches, the success rate is high. We believe that the retrograde aortic approach remains a key tool for this challenging ablation.

Feasibility and Safety of Laparoscopic-Guided Epicardial Access for Ventricular Tachycardia Ablation.

Background The usual approach to epicardial access in patients with Chagas cardiomyopathy and megacolon is surgical access to avoid bowel injury. However, there are concerns regarding its safety in cases of Chagas cardiomyopathy with reports of prolonged mechanical ventilation and high mortality in this clinical setting. The aim of this study was to examine feasibility and complication rates for ventricular tachycardia ablation performed with laparoscopic-guided epicardial access. Methods and Results This single center study examined complication rates of the first 11 cases of ventricular tachycardia ablation in patients with Chagas cardiomyopathy, using laparoscopic guidance to access epicardial space. All 11 patients underwent epicardial VT ablation using laparoscopic-guided epicardial access, and the complication rates were compared with historical medical reports. The main demographic features of our population were age, 63±13 years; men, 82%; and median ejection fraction, 31% (Q1=30% and Q3=46%). All patients were sent for ventricular tachycardia ablation because of medical therapy failure. The reason for laparoscopy was megacolon in 10 patients and massive liver enlargement in 1 patient. Epicardial access was achieved in all patients. Complications included 1 severe cardiogenic shock and 1 phrenic nerve paralysis. No intra-abdominal organ injury occurred; only 1 death, which was caused by progressive heart failure, was reported more than 1 month after the procedure. Conclusions Laparoscopic-guided epicardial access in the setting of ventricular tachycardia ablation and enlarged intra-abdominal organ is a simple alternative to more complex surgical access and can be performed with low complication rates.

Implantable cardioverter-defibrillator in Chagas heart disease: A systematic review and meta-analysis of observational studies.

BACKGROUND: In patients with Chagas cardiomyopathy (ChCM), sudden cardiac death (SCD) is the leading cause of mortality. Implantable cardioverter-defibrillator (ICD) is a well-established therapy for secondary prevention in patients with structural heart disease, but there are conflicting opinions regarding its efficacy and safety in patients with ChCM. The aim of this meta-analysis was to assess the efficacy of the ICD for secondary prevention in patients with ChCM, comparing mortality as the primary outcome of patients treated with ICD with those treated with amiodarone. METHODS: We systematically searched five databases for studies assessing mortality outcomes in patients with ChCM and sustained ventricular tachycardia (VT) treated with ICD implantation or with amiodarone. The results of studies were pooled using random-effects modeling. RESULTS: There was no randomized clinical trial comparing efficacy of ICD versus medical treatment in patients with ChCM. Six observational studies were included, totalizing 115 patients in amiodarone group and 483 patients in ICD group. The mortality outcome in the ICD population was 9.7 per 100 patient-years of follow-up (95%CI 5.7-13.7) and 9.6 per 100 patient-years in the amiodarone group (95%CI 6.7-12.4) (p = 0.95). Meta-regression did not show any association with LV ejection fraction (p = 0.32), age (p = 0.44), beta-blocker (p = 0.33) or angiotensin-converting enzyme inhibitors (p = 0.096) usage. CONCLUSION: The best available evidence derived from small observational studies suggests that ICD therapy in secondary prevention of sudden death (VT or resuscitated SCD) is not associated with lower rate of all-cause mortality in patients with ChCM. Randomized controlled trials are needed to answer this question.

Mechanical Dispersion Assessed by Strain Echocardiography Is Associated with Malignant Arrhythmias in Chagas Cardiomyopathy.

BACKGROUND: Sudden death is one of the characteristics of Chagas disease (ChD). With the development of strategies for the prevention of malignant arrhythmias, especially with implantable cardioverter-defibrillators (ICDs), there is interest in developing strategies to predict sudden cardiac death. The aim of this study was to test the hypothesis that global longitudinal strain (GLS) and mechanical dispersion (MD) may be associated with malignant ventricular arrhythmias in patients with ChD. METHODS: A cross-sectional study was conducted including 62 patients with ChD who were separated into two groups according to ICD implantation status. Group 0 consisted of 34 patients with ChD without ICDs, and group 1 comprised 28 patients with ICDs. Complete echocardiographic studies, including GLS and MD measurements, were performed in all patients. RESULTS: Chamber dimensions, ejection fraction, and diastolic function showed no significant differences between patients with and those without ICDs. GLS was reduced in patients with ChD with ICDs compared with those without (P = .02). By receiver operating characteristic curve analyses, GLS identified patients with ChD with ICDs with sensitivity of 67% and specificity of 69%. MD was more pronounced in patients with ChD with ICDs compared with those without (P < .001), with a C statistic of 0.83 (95% CI, 0.71-0.91). MD > 57 msec detected ICD presence with sensitivity of 79% and specificity of 71% and was superior to GLS and ejection fraction (P < .05). In multivariate analysis, New York Heart Association functional class (odds ratio, 3.02; 95% CI, 1.09-8.39; P = .03), MD (odds ratio, 1.11; 95% CI, 1.04-1.19; P = .001), and GLS (odds ratio, 0.72; 95% CI, 0.54-0.96; P = .026) were significant and independently associated with malignant arrhythmic events. CONCLUSIONS: GLS and MD may add important information in the risk stratification of patients with ChD. The use of MD by strain echocardiography could be an attractive tool in the decision making for ICD placement as primary prevention for sudden cardiac death in patients with ChD.