Which statement is true about the QRS duration across all listed rhythms?

The correct answer indicates that the QRS duration is always less than 0.12 seconds for many normal and common dysrhythmias. This standard reflects that a normal QRS complex typically ranges from 0.06 to 0.10 seconds.

In a healthy heart, the QRS duration represents the time it takes for electrical impulses to travel through the ventricles. When the duration exceeds 0.12 seconds, it often indicates a delay in ventricular conduction, such as in bundle branch blocks or other abnormal rhythms. Therefore, the statement that the QRS duration is always less than 0.12 seconds aligns with the definition of normal conduction patterns, highlighting that in many common arrhythmias, the QRS duration will not exceed this threshold, making it a crucial aspect of rhythm interpretation.

The other options do not accurately reflect the variability in QRS durations or the established norms. For instance, stating that the QRS duration is always greater than 0.12 seconds would not hold true for normal rhythms. Similarly, while the QRS duration can vary depending on the specific dysrhythmia, categorizing it as always less than 0.12 sec accurately encapsulates many conditions in which the QRS remains within normal limits