The QRS Complex of the Electrocardiogram Begins

Question

The QRS complex of the electrocardiogram begins .
A) well after ventricular contraction
B) just prior to ventricular contraction
C) just prior to atrial contraction
D) just after ventricular contraction begins

Accepted Answer

The QRS complex represents the electrical depolarization of the ventricles, which triggers ventricular contraction. Therefore, it occurs just prior to the contraction of the ventricles.