ECG Electrophysiology Basics

Question 1

What ions are primarily responsible for the cardiac action potential?

Accepted Answer

Sodium, potassium, and calcium

Answer

Only sodium and potassium

Answer

Iron and magnesium

Answer

Chloride and phosphate

Question 2

What is the refractory period of cardiac cells?

Accepted Answer

The time during which cells cannot be re-stimulated to contract

Answer

The resting period between heartbeats

Answer

The time it takes for blood to fill the chambers

Answer

The duration of the T wave

Question 3

What is automaticity in cardiac electrophysiology?

Accepted Answer

The ability of certain cardiac cells to generate their own electrical impulses

Answer

The automatic recording feature of ECG machines

Answer

The heart's response to exercise

Answer

The regulation of blood pressure

Question 4

What is the difference between depolarization and repolarization?

Accepted Answer

Depolarization is electrical activation; repolarization is electrical recovery

Answer

They are the same process

Answer

Depolarization occurs only in atria

Answer

Repolarization occurs only in ventricles

Question 5

What is the intrinsic rate of the AV node when it acts as the pacemaker?

Accepted Answer

40-60 beats per minute

Answer

60-100 beats per minute

Answer

20-40 beats per minute

Answer

100-150 beats per minute

Question 6

What is conductivity in cardiac tissue?

Accepted Answer

The ability to transmit electrical impulses from cell to cell

Answer

The ability to contract

Answer

The ability to respond to stimuli

Answer

The ability to return to resting state