Background: Accurate and expedited identification of scar regions most prone to reentry is needed to guide ventricular tachycardia (VT) ablation. We aimed to prospectively assess outcomes of VT ablation guided primarily by the targeting of deceleration zones (DZ) identified by propagational analysis of ventricular activation during sinus rhythm. Methods: Patients with scar-related VT were prospectively enrolled in the University of Chicago VT Ablation Registry between 2016 and 2018. Isochronal late activation maps annotated to the latest local electrogram deflection were created with high-density multielectrode mapping catheters. Targeted ablation of DZ (>3 isochrones within 1cm radius) was performed, prioritizing later activated regions with maximal isochronal crowding. When possible, activation mapping of VT was performed, and successful ablation sites were compared with DZ locations for mechanistic correlation. Patients were prospectively followed for VT recurrence and mortality. Results: One hundred twenty patients (median age 65 years [59-71], 15% female, 50% nonischemic, median ejection fraction 31%) underwent 144 ablation procedures for scar-related VT. 57% of patients had previous ablation and epicardial access was employed in 59% of cases. High-density mapping during baseline rhythm was performed (2518 points [1615-3752] endocardial, 5049±2580 points epicardial) and identified an average of 2±1 DZ, which colocalized to successful termination sites in 95% of cases. The median total radiofrequency application duration was 29 min (21-38 min) to target DZ, representing ablation of 18% of the low-voltage area. At 12±10 months, 70% freedom from VT recurrence (80% in ischemic cardiomyopathy and 63% in nonischemic cardiomyopathy) was achieved. The overall survival rate was 87%. Conclusions: A novel voltage-independent high-density mapping display can identify the functional substrate for VT during sinus rhythm and guide targeted ablation, obviating the need for extensive radiofrequency delivery. Regions with isochronal crowding during the baseline rhythm were predictive of VT termination sites, providing mechanistic evidence that deceleration zones are highly arrhythmogenic, functioning as niduses for reentry.

No abstract

Background: Catheter ablation as first-line therapy for ventricular tachycardia (VT) at the time of implantable cardioverter defibrillator (ICD) implantation has not been adopted into clinical guidelines. Also, there is an unmet clinical need to prospectively examine the role of VT ablation in patients with non-ischemic cardiomyopathy (NICM), an increasingly prevalent population referred for advanced therapies globally. Methods: We conducted an international, multi-center, randomized controlled trial enrolling 180 patients with cardiomyopathy and monomorphic VT with an indication for implantable cardioverter defibrillator (ICD) implantation to assess the role of early, first-line ablation therapy. A total of 121 patients were randomized (1:1) to ablation + an ICD versus conventional medical therapy + an ICD. Patients who refused ICD (n=47) were followed in a prospective registry after stand-alone ablation treatment. The primary outcome was a composite endpoint of VT recurrence, cardiovascular hospitalization, or death. Results: Randomized patients had a mean age of 55 years old (IQR 46-64) and left ventricular ejection fraction of 40 % (IQR 30-49 %); 81 % were male. The underlying heart disease was ischemic cardiomyopathy (ICM) in 35 %, NICM in 30 %, and arrhythmogenic cardiomyopathy (ARVC) in 35 %. Ablation was performed a median of 2 days prior to ICD implantation (IQR 5 days prior to 14 days after). At 31-months, the primary outcome occurred in 49.3 %of the ablation group and 65.5 % in the control group (HR 0.58, 95 % CI, 0.35-0.96; P=0.04). The observed difference was driven by a reduction in VT recurrence in the ablation arm (HR 0.51 [95 %CI, 0.29-0.90 ]; P=0.02). A statistically significant reduction in both ICD shocks (10.0 vs 24.6 %; p=0.03) and anti-tachycardia pacing (16.2 % vs 32.8 %; p=0.04) was observed in patients who underwent ablation compared with control. No differences in cardiovascular hospitalization (32.0 % vs. 33.7 %; HR 0.82 [95 % CI, 0.43-1.56 ]; P=0.55) or mortality (8.9% vs 8.8 %, HR 1.40 [95 %CI, 0.38-5.22 ]; P=0.62]) were observed. Ablation-related complications occurred in 8.3 % of patients. Conclusions: Among patients with cardiomyopathy of varied etiologies, early catheter ablation performed at the time of ICD implantation significantly reduced the composite primary outcome of VT recurrence, cardiovascular hospitalization, or death. These findings were driven by a reduction in ICD therapies.

Precise prevalence of atrial fibrillation (AF) and the associated risk factors in southern China are rarely reported. This large population-based follow-up study, the Guangzhou Heart Study, was conducted from 2015 to 2017 to fill up this gap. Permanent residents aged 35 years and above in Guangzhou city were enrolled and demographic factors of participants were collected by a structured questionnaire. Examinations of physical, electrocardiographic and biochemical indicators were performed following a standard operation procedure designed prior to the field investigation. Descriptive statistics were used to evaluate basic characteristics of the study participants, and multivariate logistic regression model was performed to assess the AF prevalence-related factors. The detailed study design, the baseline characteristics and the prevalence of AF were reported here. In total, 12,013 residents were enrolled, and the percentage of participants from rural and urban areas was 53.92% and 46.08%, respectively. In total, 90.57% participants aged 40–79 years old and the proportion of women was more than men (64.98% vs. 35.02%). Overall, the prevalence of AF among the participants was 1.46%. Increasing age, male sex and widowed marital status were associated with higher AF prevalence (P-value < 0.05). The prevalence of AF increased with age and climbed to approximately 5% in residents aged 80 years and over. Residents with abnormal higher blood level of total cholesterol tended to have a lower AF prevalence but a higher prevalence of AF was observed in female participants with lower level of high density lipoprotein cholesterol land higher level uric acid (all P-value < 0.05). Personal illness such as hypertension, diabetes mellitus, dyslipidemia, myocardial infarction, heart failure, stroke and transient ischemic were significantly linked to the attack of AF (all P-value < 0.05). This study will be rich resource for investigating environmental exposure and individual genetic diathesis of AF and other common cardiovascular diseases in Chinese population.