Original Investigation
Idiopathic Ventricular Arrhythmias Originating From the Pulmonary Sinus Cusp: Prevalence, Electrocardiographic/Electrophysiological Characteristics, and Catheter Ablation

https://doi.org/10.1016/j.jacc.2015.09.094Get rights and content
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Abstract

Background

Idiopathic ventricular arrhythmias (VAs) originating from the pulmonary sinus cusp (PSC) have not been sufficiently clarified.

Objectives

The goal of this study was to investigate the prevalence, electrocardiographic characteristics, mapping, and ablation of idiopathic VAs arising from the PSC.

Methods

Data were analyzed from 218 patients undergoing successful endocardial ablation of idiopathic VAs with a left bundle branch block morphology and inferior axis deviation.

Results

Twenty-four patients had VAs originating from the PSC. In the first 7 patients, initial ablation performed in the right ventricular outflow tract failed to abolish the clinical VAs but produced a small change in the QRS morphology in 3 patients. In all 24 patients, the earliest activation was eventually identified in the PSC, at which a sharp potential was observed preceding the QRS complex onset by 28.2 ± 2.9 ms. The successful ablation site was in the right cusp (RC) in 10 patients (42%), the left cusp (LC) in 8 (33%), and the anterior cusp (AC) in 6 (25%). Electrocardiographic analysis showed that RC-VAs had significantly larger R-wave amplitude in lead I and a smaller aVL/aVR ratio of Q-wave amplitude compared with AC-VAs and LC-VAs, respectively. The R-wave amplitude in inferior leads was smaller in VAs localized in the RC than in the LC but did not differ between VAs from the AC and LC.

Conclusions

VAs arising from the PSC are not uncommon, and RC-VAs have unique electrocardiographic characteristics. These VAs can be successfully ablated within the PSC.

Key Words

mapping
pulmonary
radiofrequency
tachycardia

Abbreviations and Acronyms

AC
anterior cusp
ASC
aortic sinus cusp
ECG
electrocardiogram
LBBB
left bundle branch block
LC
left cusp
PA
pulmonary artery
PSC
pulmonary sinus cusp
PV
pulmonary valve
PVC
premature ventricular contraction
RC
right cusp
RF
radiofrequency
RFCA
radiofrequency catheter ablation
RV
right ventricle
RVOT
right ventricular outflow tract
SR
sinus rhythm
VA
ventricular arrhythmia
VT
ventricular tachycardia

Cited by (0)

The authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Z. Liao and Zhan contributed equally to this work.

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