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.