Impact of timing of recurrence following catheter ablation of scar-related ventricular tachycardia on subsequent mortality.

BACKGROUND: Catheter ablation (CA) has an established role in scar-related ventricular tachycardia (VT), but the risk of recurrences is substantial and the appropriate intensity of postablation monitoring unknown. The implication of timing of postablation VT recurrence has not been adequately investigated. METHODS: We studied 120 consecutive patients with scar-related VT (age 60 ± 15 years, left ventricular ejection fraction 39 ± 16%, 52% ischemic etiology) with at least 2 years of follow-up. Timing of VT recurrence was classified as very early (<1 month), early (1-6 months), or late (>6 months). RESULTS: At 24 months follow-up, 53 (44%) patients had recurrent VT, with eight (15%) having very early recurrence, 17 (32%) early recurrence, and 28 (53%) late recurrence. Mortality rates at 2 years were significantly higher in patients with very early VT recurrence (38%) compared to those with early (12%), late (7%), and no (3%) recurrences (log-rank P < 0.001). Very early VT recurrence was associated with an increased risk of death (odds ratio = 5.68, 95% confidence interval = 1.06-30.62, P = 0.04), while recurrent VT beyond 6 months was not associated with increased risk of mortality (P = 0.94). CONCLUSIONS: Timing of VT recurrence following CA of scar-related VT impacts subsequent risk of mortality. Patients experiencing VT recurrence within 1-6 months from the procedure are at particularly high risk. These data support the importance of intense postablation monitoring for at least 6 months after the procedure to identify patients with early VT recurrence who may benefit from additional therapeutic interventions to improve outcomes.

Electrical Storm in Patients with Implantable Cardioverter-defibrillators: A Practical Overview.

Electrical storm (ES) is an increasingly common medical emergency characterized by clustered episodes of sustained ventricular arrhythmias (VAs) that lead to repeated appropriate implantable cardioverter-defibrillator (ICD) therapies. A diagnosis of ES can be made with the occurrence of three or more sustained episodes of VAs, or of three or more appropriate ICD therapies within 24 hours in patients with implanted devices. ES is associated with poor outcomes in patients with structural heart disease, particularly those with severe left ventricular dysfunction. In large clinical trials involving patients with ICDs for primary and secondary prevention, ES appears to be a predictor of cardiac death, with notably higher rates of mortality soon after the event. ES management is challenging and requires special medical attention with accurate patient risk stratification and a multidisciplinary approach that includes the use of pharmacologic therapies such as antiarrhythmic drugs (AADs) and interventional approaches like catheter ablation, surgical ablation, or sympathetic neuromodulation. Initial management involves determining and addressing the underlying ischemia, any electrolyte imbalances, and/or other causative factors. Hemodynamic support needs to be considered in high-risk patients with unstable VAs or those with severe comorbidities such as low left ventricular ejection fraction, advanced New York Heart Association class, and/or chronic pulmonary disease. Following the acute phase of ES, treatment should shift towards maximizing therapeutic efforts to address heart failure, performing revascularization, and preventing subsequent VAs. In the present manuscript, we offer an overview of the most relevant clinical aspects of ES with regard to novel therapeutic strategies.

Acute hemodynamic decompensation during catheter ablation of scar-related ventricular tachycardia: incidence, predictors, and impact on mortality.

BACKGROUND: The occurrence of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing radiofrequency catheter ablation of scar-related ventricular tachycardia (VT) has not been previously investigated. METHODS AND RESULTS: We identified univariate predictors of periprocedural AHD in 193 consecutive patients undergoing radiofrequency catheter ablation of scar-related VT. AHD was defined as persistent hypotension despite vasopressors and requiring mechanical support or procedure discontinuation. AHD occurred in 22 (11%) patients. Compared with the rest of the population, patients with AHD were older (68.5±10.7 versus 61.6±15.0 years; P=0.037); had a higher prevalence of diabetes mellitus (36% versus 18%; P=0.045), ischemic cardiomyopathy (86% versus 52%; P=0.002), chronic obstructive pulmonary disease (41% versus 13%; P=0.001), and VT storm (77% versus 43%; P=0.002); had more severe heart failure (New York Heart Association class III/IV: 55% versus 15%, P<0.001; left ventricular ejection fraction: 26±10% versus 36±16%, P=0.003); and more often received periprocedural general anesthesia (59% versus 29%; P=0.004). At 21±7 months follow-up, the mortality rate was higher in the AHD group compared with the rest of the population (50% versus 11%, log-rank P<0.001). CONCLUSIONS: AHD occurs in 11% of patients undergoing radiofrequency catheter ablation of scar-related VT and is associated with increased risk of mortality over follow-up. AHD may be predicted by clinical factors, including advanced age, ischemic cardiomyopathy, more severe heart failure status (New York Heart Association class III/IV, lower ejection fraction), associated comorbidities (diabetes mellitus and chronic obstructive pulmonary disease), presentation with VT storm, and use of general anesthesia.