A PVC originating from the left ventricle and propagating to the right ventricle would produce what in lead V1?

A PVC originating from the left ventricle and propagating to the right ventricle would produce what in lead V1?

• A. Positive deflection in V1
• B. Negative deflection in V1
• C. No deflection in V1
• D. Biphasic in V1

Answer: (A)

The main idea is that the polarity of the QRS in a given lead follows the direction of ventricular activation relative to that lead’s axis. A PVC that starts in the left ventricle and spreads to the right ventricle creates a depolarization vector directed toward the right side of the chest. Lead V1 sits on the right side and is oriented toward the right ventricle, so a wavefront moving toward V1 produces a positive deflection. Thus, an LV-to-RV PVC would show a positive QRS in V1.

The main idea is that the polarity of the QRS in a given lead follows the direction of ventricular activation relative to that lead’s axis. A PVC that starts in the left ventricle and spreads to the right ventricle creates a depolarization vector directed toward the right side of the chest. Lead V1 sits on the right side and is oriented toward the right ventricle, so a wavefront moving toward V1 produces a positive deflection. Thus, an LV-to-RV PVC would show a positive QRS in V1.