Question

which of the following represents ventricular depolarization, or contraction? a pr interval b qrs wave c st segment d t wave

Explanation:

To determine which option represents ventricular depolarization (contraction), we analyze each:

• PR interval: Represents atrial depolarization and AV node delay, not ventricular depolarization.
• QRS wave: In an ECG, the QRS complex is associated with ventricular depolarization (and subsequent contraction).
• ST segment: Represents the time between ventricular depolarization and repolarization (ventricular muscle is depolarized here, but it's not the depolarization event itself).
• T wave: Represents ventricular repolarization, not depolarization.

So the QRS wave is the correct choice.

Answer:

B. QRS wave