How many small squares does a widened QRS complex span on an EKG?

How many small squares does a widened QRS complex span on an EKG?

• A. 1 small box
• B. 2 small boxes
• C. 3 small boxes or more
• D. 4 small boxes or more

Answer: (C)

A widened QRS complex typically spans three small squares or more on an EKG. A normal QRS complex length is generally up to 0.10 seconds, which corresponds to two and a half small squares on the standard EKG grid. When the duration exceeds this, particularly reaching three small squares, it indicates a delay in ventricular conduction, such as a bundle branch block. This widening often suggests some underlying cardiac condition that requires further evaluation. Thus, identifying a QRS complex that spans three small squares or more is crucial for diagnosing various arrhythmias and heart disorders.