Kaplan Prep - ECG

Question 1

What is an ECG?

Answer 1

It is a device used to measure electrical impulses in the heart

Question 2

Where does the electrical impulse for the heart begin?

Answer 2

It begins at the SA node (sinotrial node) found in the right atrium.

Question 3

The SA node is also known as?

Answer 3

It is also known as the “pacemaker” of the heart.

Question 4

Step by the step movement of an electrical impulse.

Answer 4

1. The electrical impulse begins at the SA node (sinoatrial node) found in the right atrium.
2. The impulse spreads through the atria creating atrial systole. 3. The impulse then travels through the AV node into the bundle of His.
3. From there, the impulse continues to ravel towards the ventricular apex.
4. Finally, it travels through the Purkinje fibers to the myocardium.

Question 5

Important waves of ECG.

Answer 5

• Atrial depolarization and atrial systole are denoted as the P-wave.
• Ventricular depolarization and ventricular systole are denoted as the QRS complex.
• Ventricular repolarization and ventricular diastole are denoted as a T-wave.
• There is no way to note the repolarization of the atria.
• Its activity is lost within the QRS complex.