BACKGROUND: Electrical storm (ES) is a life- threatening condition. Both recurrence and mortality rates remain unacceptably high. Current guidelines recommend initial conservative approach using anti-arrhythmic drugs (AADs), followed by catheter ablation (CA) for those with refractory ES. METHODS: We searched PubMed and Scopus for articles comparing an initial conservative approach - based on AADs/ sedation- with an early referral for CA approach. The primary endpoint was long term mortality, while secondary endpoints included ES recurrence and the incidence of ventricular arrhythmias (VAs)/ defibrillator shocks during the follow- up. RESULTS: Seven studies, primarily observational cohorts, were analyzed. The pooled population (999 patients) consisted mostly of males with ischemic cardiomyopathy, presenting with ventricular tachycardias (VTs). The mean left ventricular ejection fraction was 35.5 % (9.5 %). 493 patients were treated with CA during the index hospitalization. Early CA was associated with significantly lower long- term mortality (OR: 0.44, 95 %CI: 0.31-0.63). Additionally, it was associated with lower rates of both ES recurrence and VAs/ shocks during the follow- up (OR: 0.27, 95 %CI: 0.15-0.48 and OR: 0.33, 95 %CI: 0.21-0.52, respectively). CONCLUSIONS: Meta- analysis of primarily observational studies revealed that early referral of ES patients for CA may improve their prognosis. The invasive approach was associated with lower mortality and reduced recurrence rates of major arrhythmic events. Although some inherent limitations affect the strength of these findings, they remain promising. They highlight the need for further research on the topic, as their confirmation in randomized trials could lead to a shift in the standard of care of ES patients.

BACKGROUND: Atrial fibrillation (AF) is the most common supraventricular arrhythmia and is associated with an impaired prognosis. Studies using implantable cardiac monitors suggest that this association is closely linked to AF burden, defined as the percentage of time spent in AF. Consequently, there is a growing need for affordable and comfortable alternative devices, such as wearables, capable of reliably monitoring AF burden in patients with AF. METHODS: Major electronic databases were searched for studies comparing AF burden quantification using wearables and reference ECG monitoring methods. A Bayesian approach was adopted for the final analysis. RESULTS: Six studies, including a total of 448 patients and 36,978 h of valid simultaneous recordings, were analyzed. Bayesian analysis revealed no statistically significant differences between wearables and reference methods in AF burden quantification. The mean error was 1% (95% CrIs: -4% to 7%). Similar findings were observed in the subgroup analysis of studies assessing only smartwatches. Between-study heterogeneity was low, and no evidence of publication bias was detected. CONCLUSION: Our analysis suggests that AF burden quantification using wearables is comparable to reference ECG monitoring methods. These findings support the potential role of wearables in clinical practice, particularly for research and prognostic purposes. However, more studies are needed to determine whether the observed statistical equivalence translates to clinical significance, thereby supporting the widespread use of wearables in the assessment of rhythm control therapeutic strategies.

Obesity is an important risk factor for atrial fibrillation (AF) development. Data on cryoballoon ablation (CBA) outcomes in obese patients have so far been scarce. We reviewed the existing literature to compare the efficacy and safety of CBA in obese versus non-obese AF patients. A systematic literature search was conducted for studies comparing clinical outcomes (arrhythmia recurrence and/or procedural data and/or safety outcomes) between obese and non-obese patients undergoing CBA for AF. Statistical pooling was performed according to a random-effects model with generic inverse-variance weighting of relative risks (RRs) and standardised mean differences (SMDs) computing risk estimates with 95% confidence intervals (CIs). Obese and non-obese patients had comparable arrhythmia recurrence rates (normal versus overweight, RR = 0.95, 95% CI: 0.82-1.11, = 0.55, I% = 91%; normal versus class I obesity, RR = 0.97, 95% CI: 0.82-1.13, = 0.68, I% = 87%; normal versus class II obesity, RR = 0.98, 95% CI: 0.91-1.07, = 0.29, I% = 65%). Procedure time was marginally increased in obese patients compared to non-obese counterparts (normal versus overweight, SMD = 0.05, 95% CI: -0.15-0.26, = 0.62, I% = 74%; normal versus class I obesity, SMD = 0.10, 95% CI: -0.00-0.19, = 0.06, I% = 2%; overweight versus class I obesity, SMD = 0.11, 95% CI: 0.01-0.21, = 0.048, I% = 25%). Regarding radiation exposure, fluoroscopy time was increased in patients with class I obesity compared to normal-weight or overweight patients and dose area product was also increased in obese patients compared to non-obese patients. Lastly, the risk of complications did not differ between obese and non-obese patients. Statistical heterogeneity and the small number of patients included are the main limitations of this study. CBA seems to be effective for obese patients suffering from AF, featuring also similar safety outcomes with non-obese individuals. Radiation exposure was increased in obese patients.