QRS duration in ventricular tachycardia is typically

• A. 0.08 seconds wide
• B. 0.20 seconds wide
• C. 0.10 seconds wide
• D. 0.12 seconds wide

Answer: (D)

QRS duration reflects how quickly the ventricles depolarize. In ventricular tachycardia, the impulse starts inside the ventricles and travels through ventricular muscle rather than the fast His-Purkinje system, so depolarization is slower and less synchronized. That makes the QRS complex broadened. Normal QRS is up to about 0.10 seconds; when the QRS is 0.12 seconds or longer, it’s considered widened and suggests a ventricular origin. So, a QRS duration of 0.12 seconds is typical for VT (and it can be longer in some cases). Narrower values like 0.08 or 0.10 seconds fit normal conduction and are not characteristic of VT.