If the QRS complex is widened and downwardly deflected in lead V1, a left bundle branch block is present. If the QRS complex is widened and upwardly deflected in lead V1, a right bundle branch ...

Mulpuru, MD: ECG is one of the greatest tools we have today to recognize LBBB. The QRS becomes wider when you have electrical dyssynchrony, and as the left ventricle is posterior in lead V1 ...

VT is frequently either in a right bundle branch block pattern (upright in V1) or a left bundle branch block pattern (downward in V1). If upward in lead V1 (RBBB pattern), then VT is present in ...

Patients who had known LBBB were included in this study ... ≥ 1 mm ST depression in V1, V2, or V3; or the ratio of the ST segment to the S wave being > 25%).