Question

Ventricular action potential duration can be measured from which interval?

Option 1: PR interval
Option 2: QT interval
Option 3: ST segment
Option 4: QRS complex duration

Answer 1

The duration of the ventricular action potential on an ECG is measured by the QT interval, encompassing both ventricular depolarization and repolarization phases.

Step-by-step explanation:

The duration of ventricular action potential can be measured from the QT interval on an electrocardiogram (ECG). The QT interval encompasses both ventricular depolarization and repolarization, starting at the beginning of the QRS complex and ending at the end of the T wave. The QRS complex signifies the depolarization of the ventricles, which leads to ventricular contraction, while the T wave indicates ventricular repolarization, which occurs during ventricular relaxation. The PR interval is instead related to atrial depolarization and the delay before the onset of the QRS complex and is not directly related to ventricular action potential duration.