IBHRE - International Board of Heart Rhythm Examiners Cardiac Anatomy and Physiology Questions and Answers

Question 1

During a catheter ablation procedure for atrioventricular nodal reentrant tachycardia (AVNRT), the electrophysiologist must exercise extreme caution to avoid the atrioventricular (AV) node.
Which anatomical landmark is critical for identifying the location of the AV node?

Accepted Answer

The Triangle of Koch

Answer

The Ligament of Marshall

Answer

Bachmann's Bundle

Answer

The Eustachian Ridge

Question 2

A patient is undergoing implantation of a biventricular pacemaker for cardiac resynchronization therapy. The physician is attempting to place the left ventricular lead via the coronary sinus. Which major cardiac vein is a direct tributary of the coronary sinus and runs in the posterior interventricular groove?

Accepted Answer

Middle Cardiac Vein

Answer

Great Cardiac Vein

Answer

Small Cardiac Vein

Answer

Anterior Cardiac Vein

Question 3

What is the primary physiological reason for the long absolute refractory period in ventricular myocardial cells?

Accepted Answer

To prevent summation of contractions and tetany of the cardiac muscle.

Answer

To allow for complete atrial emptying before ventricular contraction.

Answer

To ensure the heart can respond to rapid successive stimuli.

Answer

To facilitate rapid repolarization and increase heart rate.

Question 4

Which of the following structures is considered the primary and most consistent pathway for electrical impulse conduction between the right and left atria?

Accepted Answer

Bachmann's Bundle

Answer

The Coronary Sinus Musculature

Answer

The Crista Terminalis

Answer

The Tendon of Todaro

Question 5

A patient's ECG shows a significantly prolonged P-wave duration, suggesting an interatrial conduction delay. Dysfunction of which anatomical structure is the most likely cause?

Accepted Answer

Bachmann's Bundle

Answer

The Atrioventricular Node

Answer

The Purkinje Fibers

Answer

The Bundle of His

Question 6

During Phase 0 of the cardiac action potential in a ventricular myocyte, the rapid depolarization is primarily caused by the influx of which ion?

Accepted Answer

Sodium (Na+)

Answer

Potassium (K+)

Answer

Calcium (Ca2+)

Answer

Chloride (Cl-)