Question

Why is ventricular repolarization a positive deflection?

A) Due to the movement of sodium ions
B) Due to the movement of potassium ions
C) Due to the movement of calcium ions
D) Due to the movement of chloride ions

Answer 1

Ventricular repolarization is depicted as a positive deflection on an ECG b) due to the movement of potassium ions out of the cardiac cells, returning the cell to its resting negative voltage.

Step-by-step explanation:

The reason why ventricular repolarization is seen as a positive deflection on an electrocardiogram (ECG) is option b) due to the movement of potassium ions (K+).

During ventricular repolarization, potassium ions move out of the cardiac cells, taking positive charges with them which causes the interior of the cell to become less positive and move back toward its resting negative voltage. This results in a positive deflection on the ECG, which is known as the T wave.