Question

---"P-R" Interval represents the time from the start of atrial depolarization, P-wave to the beginning of the QRS, or ventricular depolarization. Normal P-R interval is .12 to .20 seconds. -

---"QRS" represents ventricular depolarization (phase 0 of the action potential) until the end of ventricular depolarization. "Q" = initial downward or negative deflection -

Answer 1

The PR interval in an ECG measures the duration from the beginning of atrial depolarization to the initiation of ventricular depolarization. The normal PR interval ranges from 0.12 to 0.20 seconds.

Step-by-step explanation:

The PR interval in an electrocardiogram (ECG) represents the time from the start of atrial depolarization (P-wave) to the beginning of ventricular depolarization (QRS complex). It measures the duration from the beginning of atrial depolarization to the initiation of ventricular depolarization. The normal PR interval ranges from 0.12 to 0.20 seconds.