Predictors of the voltage derived left atrial fibrosis in patients with long-standing persistent atrial fibrillation

Background: Left atrial (LA) arrhythmogenic substrate beyond the pulmonary veins (PV) seems to play a crucial role in the maintenance of atrial fibrillation (AF). The aim of this study was to evaluate the association of selected parameters with the presence and extent of voltage-defined LA fibrosis in patients with long-standing persistent AF (LSPAF) undergoing catheter ablation. Methods: One hundred and sixteen consecutive patients underwent high density-high resolution voltage mapping of the LA with a multielectrode catheter following PV isolation and restoration of sinus rhythm with cardioversion. A non-invasive dataset, such as clinical variables, two-and three-dimensional echocardiography determined LA size and function and fibrillatory-wave amplitude on a standard surface electrocardiogram were obtained during AF before ablation. Results: Low-voltage areas (LVA; 15 cm2 [IQR 8–31]) were detected in 56% of patients. Twenty nine percent of them presented mild, 43% moderate and 28% severe global LVA burden. In univariate analysis, age ≥ 57 years old, female sex, body surface area ≤ 1.76 m2, valvular heart disease, moderate mitral regurgitation, chronic coronary syndrome, hypothyroidism, CHA2DS2-VASc score ≥ 3 and ≥ 4 predicted the presence of LVA. In multivariate analysis only female sex, valvular heart disease and CHA2DS2-VASc ≥ 4 remained statistically significant. AF duration, LA size and function and fibrillatory-waves amplitude were neither associated with the prediction of the LVA, nor severe LVA burden. Conclusions: A LSPAF diagnosis does not indicate the presence of voltage defined fibrosis in many cases. Simple non-invasive screening of the LSPAF population could predict LVA prevalence

Does a Vagal Response Indicate Cardiac Autonomic Modulation and Improve the Therapeutic Effect of Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation? Insights from Cryoballoon Ablation

Background: The incidence and influence of vagal response (VR) observed during cryoballoon-based pulmonary vein isolation (CBA-based PVI) on the cardiac autonomic nervous system (CANS) and ablation outcomes in paroxysmal atrial fibrillation (PAF) remain unknown. Methods: 296 patients were treated with a 28 mm second-generation cryoballoon (Medtronic). A total of 74 patients without structural heart disease and concomitant diseases were chosen for a detailed CANS assessment with a heart rate variability (HRV) analysis. All patients were screened over a 2-year post-ablation period. Results: VR was detected in 30% of patients and included sinus arrest (64%) or severe sinus bradycardia (46%). The presence of VR was not related to PV ostial dimension, patient clinical characteristics or intraprocedural ablation details. CANS modulation, manifesting as increased median HR and decreased HRV parameters with intact sympatho-vagal balance occurred independently of VR presence or absence and sustained for at least 12 months following ablation. VR was not related with more intensive CANS modulation and did not translate into better ablation outcomes when compared to the non-VR group (74% vs. 71% at 12 months and 69% vs. 65% at 24 months respectively). Conclusions: VR is frequent during CBA-based PVI for PAF and unrelated to any additional clinical benefit