Electrophysiological predictors of ventricular tachycardia recurrence in patients with structural heart disease after combined endo-epicardial substrate catheter ablation

Background

Although there is a tremendous improvement in mapping and ablation techniques over the last decades, the recurrence rate of ventricular tachycardia (VT) in patients with structural heart diseases following endo-epicardial catheter ablation remains high.

Purpose

To determine predictors of VT recurrence in patients with structural heart disease after combined endo-epicardial radiofrequency (RF) VT ablation.

Methods

This prospective single-center study included 39 patients (34 men and 5 women, mean age 49.6±16.0 years), who underwent endo-epicardial mapping and ablation of the VT substrate. Etiology of structural heart diseases included: previous myocardial infarction (n=15); non-ischemic cardiomyopathy (n=24: 15 – arrhythmogenic right ventricular cardiomyopathy (ARVC), 6 – myocarditis, 3 – unspecified). First-line epicardial access was performed in 16 patients, as a second approach – in 23 subjects. We evaluated total ventricular myocardial areas, epi- and endocardial areas with bipolar low voltage (<1.5mV), scar area (bipolar <0.5mV), and unipolar low voltage (<5.0mV) and transient (<8.0mV) areas; areas of late potential registration were evaluated. Ratios of transient, low amplite and late-potential areas were calculated for endo- and epicardial surfaces, bipolar and unipolar maps. The following procedural electrophysiology characteristics were considered: inducibility of clinical VT, the number and morphology of induced VT, QRS width on sinus rhythm and VT, tachycardia cycle length, pseudo-delta wave extant and width, internal activation time, intrisicoud deflection time, and RS length. Clinical data such as echocardiography parameters, comorbidity and antiarrhythmic drug therapy were also taken into account. VT recurrences were documented using ICD/CRT-D interrogation, event ECG monitoring. Follow-up included mandatory visits at 6 and 12 months and unscheduled visits.

Results

Epicardial late potentials were registered in 69% of cases before ablation. Epicardial RF applications were delivered in 67% of patients; while only endocardial RF applications (including cases with intended epicardial substrate modification by endocardial ablation) were present in 28% cases. Non-inducibility of any VT plus abatement of local abnormal electrical activity was achieved in 32 (82%) of cases. The ratio epi/endo bipolar areas <0.5mV was much higher in patients with vs without VT recurrence at 6 months (4.3 (IQR: 2.5; 8.2) vs 0.75 (IQR:0.4; 1.6), P=0.001). A strong negative correlation was found between the induced VT cycle length and the ratio epi/endo bipolar areas <0.5mV: the shorter induced VT cycle length -the larger the area of the epicardial low voltage area (r=−0,52).

Conclusion

Regardless of epicardial substrate modification, patients with a larger epicardial low voltage area are more likely to have VT recurrence at 6 months after index ablation. A shorter induced VT cycle length is associated with a larger epicardial low-voltage area.

Funding Acknowledgement

Type of funding sources: None.

Different Expressions of Pericardial Fluid MicroRNAs in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy and Ischemic Heart Disease Undergoing Ventricular Tachycardia Ablation

Introduction: Pericardial fluid is enriched with biologically active molecules of cardiovascular origin including microRNAs. Investigation of the disease-specific extracellular microRNAs could shed light on the molecular processes underlying disease development. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart disease characterized by life-threatening arrhythmias and progressive heart failure development. The current data about the association between microRNAs and ARVC development are limited.

Methods and Results: We performed small RNA sequence analysis of microRNAs of pericardial fluid samples obtained during transcutaneous epicardial access for ventricular tachycardia (VT) ablation of six patients with definite ARVC and three post-infarction VT patients. Disease-associated microRNAs of pericardial fluid were identified. Five microRNAs (hsa-miR-1-3p, hsa-miR-21-5p, hsa-miR-122-5p, hsa-miR-206, and hsa-miR-3679-5p) were found to be differentially expressed between patients with ARVC and patients with post-infarction VT. Enrichment analysis of differentially expressed microRNAs revealed their close linkage to cardiac diseases.

Conclusion: Our data extend the knowledge of pericardial fluid microRNA composition and highlight five pericardial fluid microRNAs potentially linked to ARVC pathogenesis. Further studies are required to confirm the use of pericardial fluid RNA sequencing in differential diagnosis of ARVC.

[Reverse remodelling of the heart after atrial fibrillation ablation in patients with heart failure with reduced ejection fraction]

AIM

To evaluate the effect of atrial fibrillation (AF) catheter ablation (CA) on long-term freedom from AF and left heart reverse remodeling in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS

There were 47 patients (mean age 53.3 ± 10 years, 39 males) enrolled into single-center observational study, with left ventricular ejection fraction (LVEF) <40 %. Patients underwent CA for AF refractory to antiarrhythmic drugs. Baseline clinical data and diagnostic tests results were obtained during personal visits and / or via secure telemedical services. Personal contact with evaluation of recurrence of AF and echocardiographic values was performed with 30 (64 %) patients.

RESULTS

Paroxysmal AF was present in 12 (40 %) patients, persistent - in 18 (60 %). During mean follow-up of 3 years (0.5-6 years) redo ablation was performed in 9 patients (30 %) with average number of 1.3 procedures per patient. At 6 months 24 (80 %) patients were free from AF, at last follow-up - 16 (53 %). The mean time to first recurrence following CA was 15.6±13.3 months. Follow-up echocardiography revealed significant LVEF improvement (р<0,0001), reduction of left atrium size (р<0,0001), left ventricle end-diastolic volume (р<0,002) and left ventricle endsystolic volume (p<0,0001) and mitral regurgitation (р=0,001).

CONCLUSION

AF CA in patients with HFrEF is associated with improvement in systolic function and left heart reverse remodeling. Durable long-term antiarrhythmic effect often requires repeated procedures.