Question

The PRI is considered abnormal or prolonged if it is ________.

1) Less than 0.12 seconds
2) Between 0.12 and 0.20 seconds
3) More than 0.20 seconds
4) Cannot be determined

Answer 1

An abnormally prolonged PR interval on an ECG is considered abnormal if it is more than 0.20 seconds, which may indicate a third-degree heart block.

Step-by-step explanation:

Abnormal PR Interval

In the case of an abnormal or prolonged PR interval, it is typically considered abnormal if it is more than 0.20 seconds. The PR interval is the time from the beginning of the P wave (atrial depolarization) to the beginning of the QRS complex (ventricular depolarization) on an electrocardiogram (ECG). An abnormally prolonged PR interval can be indicative of a third-degree heart block, where there is no correlation between atrial and ventricular activity.