Εlectrocardiographic and electrophysiological characteristics of
idiopathic ventricular arrhythmias with acute successful ablation at the
left ventricle basal inferoseptum near the mitral annulus
Abstract
Introduction: We sought to clarify the electrocardiographic and
electrophysiological characteristics of ventricular arrhythmias (VAs),
including idiopathic ventricular tachycardia (VT) and premature
ventricular contractions (PVCs), with acute successful radiofrequency
catheter ablation (RFCA) at the left ventricle basal inferoseptum near
the mitral annulus (LV-BIS-MA). Methods and Results: Twenty-five
patients with acute successful RFCA at the LV-BIS-MA were included in
this study. The S wave amplitudes on lead III during VAs were 1.54 ±
0.38 mV, significantly larger than that on lead II (0.55 ± 0.19 mV) and
aVF (1.04 ± 0.31 mV) (P < 0.01). The RFCA start-to-effect time
was 10.2 ± 5.8 seconds (s) in 21 patients (84.0%). In the remaining 4
patients (16.0%), the mean duration of successful RFCA was not well
determined due to infrequent nature of clinical VAs during ablation.
Trans-septal approach were utilized in all the 25 cases. Intra-cardiac
echocardiography (ICE) showed that the ablation catheter tip was
underneath the anterior leaflet of the mitral valve via the reversed
C‐curve technique. Early (within 3 days) and late (one-year) recurrence
rates were 4.0% (one patient) and 12.0% (three patients),
respectively. No complications occurred during RFCA or the one-year
follow up. CONCLUSION: LV-BIS-MA VAs are a subgroup of idiopathic VAs
with distinctive ECG and EP features. RFCA via a transseptal approach
using a reversed C curve technique is effective for better
identification and targeting the areas of VAs origin and ICE showed that
the ablation catheter tip was underneath the anterior leaflet of the
mitral valve.