In ventricular tachycardia (VT), which lead would be predominantly positive?

In ventricular tachycardia (VT), the lead that is predominantly positive is often V1. This is due to the direction of the depolarization wavefront during ventricular tachycardia, which typically originates from the ventricles and moves through the cardiac muscle, resulting in a positive deflection in certain precordial leads depending on the axis of the tachycardia.

In many cases of VT, particularly in right ventricular outflow tract VT, the complexes seen in V1 can show a primarily positive morphology due to the orientation of the electrical activity. As the depolarization moves away from lead V1 towards the left ventricle, the recorded voltage tends to be positive because the lead is placed closer to the right side of the heart, where the depolarization wave typically heads into the left ventricle.

This understanding aligns with normal cardiac conduction pathways and how the electrical impulses travel during an abnormal rhythm such as VT. Recognizing the primarily positive lead in instances of VT is crucial for accurate identification and subsequent management of the arrhythmia, thereby enhancing patient care.