Background: Ventricular tachycardia (VT) storm is associated with significantly increased morbidity, mortality, and exponential healthcare utilization. Although catheter ablation (CA) may be curative, there are limited data directly comparing outcomes of early CA with initial medical therapy. Methods: We compared outcomes of patients presenting with VT storm treated with initial CA versus those treated with initial medical therapy during their first storm presentation in an observational study. Retrospective data from the host institution from January 2014 to April 2020 of 129 patients with their first VT storm presentation were analyzed (58 underwent initial CA, 71 underwent treatment with initial medical therapy). Outcomes were compared in follow-up. Results: Median time to initial CA was 6 days. Over a median follow-up of 702 days, patients who underwent initial CA compared with those treated with initial medical therapy had significantly less: (i) VA recurrence (43% versus 92%; P =0.002); (ii) VT storm recurrence (28% versus 73%; P <0.001); (iii) composite end point of death, heart transplant, VT storm recurrence, and VT-related hospitalization (47% versus 89%; P =0.002); (iv) iatrogenic complications (at 12 months: 17% versus 45%; P <0.001); (v) cardiovascular-related hospitalizations (50% versus 89%; P =0.01); (vi) total number of hospitalizations (median 1 versus 4; P <0.001); and (vi) cumulative days in hospital (median 0.5 versus 18; P <0.001). There were no intraprocedural deaths in patients treated with early CA. Conclusion: In an observational setting in which patients presenting with storm, early CA appears superior to initial medical therapy in terms of VT recurrence, storm recurrence, iatrogenic complications, cardiovascular hospitalizations, and cumulative days in hospital in follow-up.

The long-term natural history of autonomic alterations following catheter ablation of drug-refractory paroxysmal atrial fibrillation is poorly defined. The authors sought to define the long-term impact of thermal catheter ablation on the cardiac autonomic system. The study included 346 patients with drug-refractory paroxysmal atrial fibrillation undergoing pulmonary vein isolation using thermal ablation energy (radiofrequency or cryoballoon ablation). All patients underwent insertion of a Reveal LINQ implantable cardiac monitor prior to ablation. The implantable cardiac monitor continuously recorded physical activity, heart rate variability (HRV) (measured as the standard deviation of the average normal-to-normal), daytime heart rate, and nighttime heart rate (NHR). Longitudinal autonomic data in the 2-month period prior to the date of ablation were compared with the 3 years following ablation. Following ablation, there was a significant decrease in HRV (10-20 ms; P < 0.0001) and significant increases in daytime heart rate and NHR (10 beats/min [P < 0.0001] and 7 beats/min [P < 0.0001], respectively). Changes in autonomic parameters were greatest in the first 3 months following ablation but remained significantly different from baseline for 36 months following ablation. Greater changes in NHR and HRV were associated with improved freedom from recurrent arrhythmia. The type of thermal ablation energy had no influence on the heart rate and autonomic parameters. Pulmonary vein isolation using thermal ablation energy results in significant sustained changes in the heart rate parameters related to autonomic function. These changes are independent of the ablation technology employed and are associated with procedural success. (Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration [CIRCA-DOSE]; NCT01913522).

Atrial fibrillation (AF) is the most common sustained cardiac dysrhythmia encountered in practice. It is currently estimated that AF affects approximately 2% of the general population; however, the true prevalence of AF is likely to be at least 3%–4% when asymptomatic AF is considered. For clinically apparent AF, the investigations and management are relatively well established. The identification of minimally symptomatic patients is challenging, and furthermore, the optimal management is less certain. Although there is some debate about the ideal treatment pathway for asymptomatic AF, in most cases, the investigations and comprehensive management follow the same recommendations as clinically apparent AF. In contrast, beyond risk factor optimisation, the ideal management of subclinical or device-detected AF remains undefined. The purpose of the current review is to discuss the assessment and management of asymptomatic AF.