Which of the following statements describes the ECG findings of Intramural septal premature ventricular contractions ?
A. RBBB morphology with inferior axis
B. RBBB morphology with superior axis
C. LBBB morphology with inferior axis
D. LBBB morphology with superior axis
Intramural septal PVCs arise from the interventricular septum. They have been described recently. In one series seven of 93 consecutive patients (8%) referred for ablation of idiopathic ventricular arrhythmias (mean age, 4914 years; 52 men; ejection fraction, 5212%) were found to have a site of origin in the interventricular septum.Five of 7 patients had symptomatic frequent premature ventricular complexes (PVCs) and 2 had frequent asymptomatic PVCs. The left ventricular ejection fraction was reduced in 2 of 7 patients who had ejection fractions of 30% and 42% before the ablation. The mean ejection fraction of the 7 patients was 55.9%. There was no evidence of structural heart disease in these patients, based on echocardiography, stress testing, and cardiac MRI.
-All 7 patients with an intramural focus had PVCs with a left bundle-branch block, inferior-axis morphology
-The differential diagnosis of a intramural septal PVC includes origin from
2. Aortic cusp
3. Para-Hisian area
There are no definite ECG findings to differential these sites of origin and final localization needs mapping.
The mapping is done through advancing a catheter through a septal perforator vein
Answer : C