The ECG shows a prolonged ______ interval, indicating delayed conduction between the atria and ventricles.
1PR✓ 정답
2QT
3ST
4QRS
5RR
해설
The PR interval represents the time taken for an electrical impulse to travel from the atria through the AV node to the ventricles. A prolonged PR interval (>200ms) indicates first-degree AV block, showing delayed conduction through the AV node.
PR interval:
- Normal duration: 120-200ms
- Measured from P wave onset to QRS complex start
- Represents atrial-ventricular conduction time
- Prolonged PR interval (>200ms) = First-degree AV block
- Components: P wave + PR segment
- Clinical significance:
* AV nodal disease
* Digitalis effect
* Increased vagal tone
* Electrolyte imbalances
- Shortened PR interval (
핵심 개념
PR interval — The time measured from the beginning of the P wave to the beginning of the QRS complex, representing atrial to ventricular conduction time
QT interval — The time from the start of the QRS complex to the end of the T wave, representing total ventricular depolarization and repolarization
ST segment — The portion of the ECG between the end of the QRS complex and the beginning of the T wave, representing early ventricular repolarization
QRS complex — The combination of three graphical deflections on an ECG representing ventricular depolarization
RR interval — The time between two consecutive R waves in the ECG, representing the duration of a complete cardiac cycle