A nurse is interpreting the cardiac rhythm for a client who is on continuous ECG monitoring. Which of the following findings should the nurse report to the provider?

Continuous ECG monitoring is used to evaluate cardiac electrical activity and identify abnormalities in impulse generation and conduction. Key intervals on the ECG reflect different phases of depolarization and repolarization of the atria and ventricles. Prolongation of certain intervals, especially the QT interval, can indicate delayed ventricular repolarization and increase the risk of life-threatening dysrhythmias such as torsades de pointes. Prompt recognition of abnormal values is essential for preventing cardiac complications. Rationale: A. A heart rate of 74/min is within the normal adult range of 60 to 100 beats per minute and does not require reporting. This rate indicates adequate cardiac output and stable sinus rhythm in most clinical situations. It is an expected finding during routine ECG monitoring. B. A QRS complex duration of 0.1 seconds is within normal limits (0.06 to 0.10 seconds). This indicates normal ventricular depolarization and intact intraventricular conduction pathways. No conduction delay or ventricular abnormality is suggested by this value. C. A QT interval of 0.5 seconds is prolonged and should be reported because it indicates delayed ventricular repolarization. This increases the risk for dangerous dysrhythmias such as torsades de pointes and sudden cardiac arrest. Prolongation may be caused by medications, electrolyte imbalances, or underlying cardiac conditions requiring prompt evaluation. D. A PR interval of 0.18 seconds is within the normal range of 0.12 to 0.20 seconds and reflects normal conduction from the atria through the AV node. This suggests intact atrioventricular conduction without evidence of heart block. It does not require immediate provider notification.