Question

Short PR interval (less than 0.12 sec) may be seen when the impulse originates in the atria close to the ____ node or in the ____ bundle. The P-R interval (PRI) is measured from the point where the _____ wave leaves the baseline to the beginning of the QRS complex. The term PQ interval is preferred by some, because it is the period that is actually measured unless a Q wave is absent. The PRI changes with heart rate but normally measures 0.12 to 0.20 seconds in adults.

1) sinoatrial, atrioventricular, P
2) sinoventricular, atrioventricular, P
3) sinoatrial, atrioventricular, Q
4) sinoventricular, atrioventricular, Q

Answer 1

A short PR interval on an ECG can be seen when the impulse is near the SA node or in the AV bundle. The PR interval is measured from the start of the P wave to the beginning of the QRS complex.

Step-by-step explanation:

A short PR interval on an electrocardiogram (ECG) may be seen when the impulse originates in the atria close to the sinoatrial (SA) node or in the atrioventricular (AV) bundle, also known as the Bundle of His. The PR interval (PRI) is the period on the ECG measured from the point where the P wave leaves the baseline to the beginning of the QRS complex. Some prefer the term PQ interval, particularly when a Q wave is not present.

The normal PR interval in adults is between 0.12 to 0.20 seconds and can change with the heart rate. Conduction disturbances such as AV blocks can alter the length of the PR interval, indicating issues within the heart's electrical conduction system.