In normal sinus rhythm, the QRS duration is within which range?

In normal sinus rhythm, the QRS duration is within which range?

• A. 0.06-0.10 s.
• B. 0.12-0.20 s.
• C. 0.02-0.04 s.
• D. 0.15-0.20 s.

Answer: (A)

QRS duration shows how long the ventricles take to depolarize. In normal sinus rhythm, the impulse travels quickly through the heart’s conduction system, producing a narrow QRS complex. A duration of about 0.06–0.10 seconds (60–100 ms) is typical for a normal QRS. Longer durations, such as 0.12–0.20 seconds, indicate conduction delay or block (like a bundle branch block), while durations that are much shorter (0.02–0.04 s) or much longer (0.15–0.20 s) are not consistent with normal ventricular depolarization. Hence, 0.06–0.10 seconds is the best match.

QRS duration shows how long the ventricles take to depolarize. In normal sinus rhythm, the impulse travels quickly through the heart’s conduction system, producing a narrow QRS complex. A duration of about 0.06–0.10 seconds (60–100 ms) is typical for a normal QRS. Longer durations, such as 0.12–0.20 seconds, indicate conduction delay or block (like a bundle branch block), while durations that are much shorter (0.02–0.04 s) or much longer (0.15–0.20 s) are not consistent with normal ventricular depolarization. Hence, 0.06–0.10 seconds is the best match.