Abstract
Introduction: Ventricular arrhythmia (VA) from the left ventricular summit (LVS) is a common origin of VA, which resulting LV dysfunction in some patients. However, the predictors of LV cardiomyopathy were not well-elucidated. The present study sought to investigate the risk factor of LV cardiomyopathy and the outcome in patients with LVS VA
Methods: Between 2013 and 2018, a total of 139 patients (60.7% men; mean age 53.2 ± 13.9 years-old) underwent catheter ablation for LVS VA from two centers. Detailed patient demographics, electrocardiograms, electrophysiological characteristics, and clinical outcomes were extracted for analysis. LV cardiomyopathy was defined as LV ejection fraction (LVEF) <50%.
Results: Acute procedural success was achieved in 92.8 % of patients. There were 40 patients (28.8%) with LV cardiomyopathy, and the mean LVEF improved from 37.5 ± 9.3% to 48.5 ± 10.2% after ablation (p < 0.001). After multivariate analysis, the independent predictors of LV dysfunction were wider QRS duration of the VA (odds ratio [OR]1.02; 95% confidence interval [CI]: 1.00-1.04; p = 0.046) and the absolute earliest activation time discrepancy (AEAD) between epicardium and endocardium (OR 1.05; 95% confidence interval CI: 1.00-1.09; p = 0.048). After ablation, the LV function was completely recovered in 20 patients (50%). The predictors for irreclaimable LV function included wider PVC QRS duration (OR 1.09; 95% CI: 1.02-1.17; p = 0.012) and poorer LVEF (OR 0.85; 95% CI: 0.74-0.97; p = 0.020).
Conclusion: In patients with VA from LVS, PVC QRS duration and AEAD predicted the deteriorating LV systolic function. Catheter ablation could reverse the LV remodeling. Narrower QRS duration and better LVEF predicted a better recovery of LV function after ablation.
Keywords: Ablation; Left ventricular summit; Left ventricular function; QRS duration; Ventricular arrhythmia; absolute earliest activation time discrepancy
Introduction
Premature ventricular complex (PVC) is a common ventricular arrhythmia (VA). PVCs can cause various symptoms often regarded as benign1, 2, but also can lead to cardiomyopathy3, 4. PVC-induced cardiomyopathies are characterized by deterioration of left ventricular (LV) function, which can be reversed after the elimination of PVCs 3-5. Several parameters have been proposed to predict PVC-induced cardiomyopathy, including the PVC burden 6, 7, PVC QRS duration8-10, origin of PVC 8, PVC coupling interval 11, symptoms, duration 12, and presence of non-sustained ventricular tachycardia (VT) or sustained VT 8. However, except for the PVC burden, the prediction values of these parameters were inconsistent. These parameters remained debated mainly, which could be due to the heterogeneous PVC origin and the non-uniform underlying cardiac disease.
PVCs originating from epicardium have been reported as a risk factor for PVC-induced cardiomyopathy 9, 13. The left ventricular summit (LVS) is the highest portion of the LV epicardium and is an important anatomic area harboring arrhythmogenic foci responsible for VA14. VAs arising from LVS frequently required multiple approach from bother epicardium and endocardial adjacent area15. There was no previous studies systemically investigated the incidence, risk factors, and reversibility of LV dysfunction with successful ablation.
The present study aims to determine the various factors associated with LV dysfunction induced by VA originating from LVS.