What is the most common location of outflow tract ventricular tachycardia?

• A. LVOT
• B. RVOT
• C. Right atrium
• D. Left ventricle apex

Answer: (B)

Outflow tract ventricular tachycardia most often originates from the right ventricular outflow tract, the infundibular region just beneath the pulmonic valve. This area tends to be a favorable substrate for focal automaticity or triggered activity, making RVOT the most common source for idiopathic VT. On the ECG, this origin typically produces a left bundle branch block pattern with an inferior axis, reflecting activation beginning high in the right ventricle and spreading downward. Because the substrate is relatively localized and accessible, catheter ablation in the RVOT is highly successful. The other locations listed are less typical sources of outflow tract VT (left ventricular outflow tract can occur but is less common; the right atrium is not a ventricular outflow site; the left ventricular apex is an apical/other site, not part of the outflow tract).