JACC. Clinical electrophysiology最新文献

Background: The evolution of myocardial scar and its arrhythmogenic potential postinfarct is incompletely understood.

Objectives: This study sought to investigate scar and border zone (BZ) channels evolution in an animal ischemia-reperfusion injury model using late gadolinium enhancement cardiac magnetic resonance (LGE-CMR).

Methods: Five swine underwent 90-minute balloon occlusion of the mid-left anterior descending artery, followed by LGE-CMR at day (d) 3, d30, and d58 postinfarct. Invasive electroanatomic mapping (EAM) was performed at 2 months. Topographical reconstructions of LGE-CMR were analyzed for left ventricular core and BZ scar, BZ channel geometry, and complexity, including transmurality, orientation, and number of entrances/exits.

Results: LVEF reduced from 48.0% ± 1.8% to 41.3% ± 2.3% postinfarct. Total scar mass reduced over time (P = 0.008), including BZ (P = 0.002) and core scar (P = 0.05). A total of 72 BZ channels were analyzed across all animals and timepoints. Channel length (P = 0.05) and complexity (P = 0.02) reduced progressively from d3 to d58. However, at d58, 64% of channels were newly formed and 36% were midmyocardial. Conserved channels were initially longer and more complex. All LGE-CMR channels colocalized to regions of maximal decrement on EAM, with significantly greater decrement (115 ± 31 ms vs 83 ± 29 ms; P < 0.001) and uncovering of split potentials (24.8% vs 2.6%; P < 0.001) within channels. In total, 3 of 5 animals had inducible VT and tended to have more channels with greater midmyocardial involvement and functional decrement than those without VT.

Conclusions: BZ channels form early postinfarct and demonstrate evolutionary complexity and functional conduction slowing on EAM, highlighting their arrhythmogenic potential. Some channels regress in complexity and length, but new channels form at 2 months' postinfarct, which may be midmyocardial, reflecting an evolving, 3-dimensional substrate for VT. LGE-CMR may help identify BZ channels that may support VT early postinfarct and lead to sudden death.

Background: Post-myocardial infarction (MI) patients with ventricular tachycardia (VT) are considered at risk for VT recurrence and sudden cardiac death (SCD). Recent guidelines indicate that in selected patients catheter ablation should be considered instead of an implantable cardioverter-defibrillator (ICD).

Objectives: This study aimed to analyze outcomes of patients referred for VT ablation according to left ventricular ejection fraction (LVEF), tolerance of VT, and acute ablation outcome.

Methods: Post-MI patients without prior ICD undergoing VT ablation at a single center between 2009 and 2022 were included. Patients who presented with tolerated VT and who had an LVEF >35% were offered catheter ablation as first-line therapy. ICD implantation was offered to all patients but was subject to shared decision according to clinical presentation, LVEF, and ablation outcome.

Results: Eighty-six patients (mean age 69 ± 9 years, 84% male, mean LVEF 41 ± 9%) underwent VT ablation. In 66 patients, LVEF was >35%, of whom 51 had tolerated VT. Of these 51 patients, 37 (73%) were rendered noninducible. In 5 of 37 noninducible and in 11 of 14 inducible patients, an ICD was implanted. During a median follow-up of 40 months (Q1-Q3: 24-70 months), 10 of 86 patients had VT recurrence. The overall mortality was 27%, and 1 patient with ICD died suddenly. Among the 37 patients (none on antiarrhythmic drugs) with LVEF >35%, tolerated VT, and noninducibility, no SCD or VT recurrence occurred. Among the 14 patients with LVEF >35%, tolerated VT, and inducibility after ablation, no SCD occurred, but VT recurred in 29%.

Conclusions: Post-MI patients with LVEF >35%, tolerated VT, and noninducibility after ablation have an excellent prognosis. Deferring ICD implantation seems to be safe in these patients.

Background: Ventricular ablation may be clinically indicated for patients with recurrent ventricular tachycardia (VT) and has been shown to decrease risk of recurrence and overall morbidity. However, the existence of disparities among patients receiving ventricular ablation has not been well characterized.

Objectives: In this study, we examined patients hospitalized with VT to determine whether disparities exist among those receiving ablations.

Methods: We used the National Inpatient Sample to assess patients hospitalized with a primary diagnosis of VT in 2019 who did and did not receive catheter ablations. Multiple logistic regression was used to calculate risk factors for VT ablation based on age, sex, race/ethnicity, socioeconomic status, and hospital characteristics.

Results: After adjusting for baseline characteristics and comorbidities, female and Black patients hospitalized with VT had significantly lower odds of receiving ablations compared with male and White patients (OR: 0.835; 95% CI: 0.699-0.997; P = 0.047; and OR: 0.617; 95% CI: 0.457-0.832; P = 0.002, respectively). Additionally, patients at rural or nonteaching hospitals were significantly less likely to receive ablations compared with those at urban, teaching hospitals. No significant differences were noted based on income or insurance status in the adjusted models.

Conclusions: We identified significant disparities in the delivery of ventricular ablations among patients hospitalized with VT. Overall, patients who were female or Black as well as those who were hospitalized at rural or nonteaching hospitals were significantly less likely to receive VT ablations during hospitalization.