Free RCIS Cardiovascular Anatomy and Physiology Questions and Answers

Question 1

The inferior wall of the left ventricle is primarily supplied by which coronary artery?

Accepted Answer

Right Coronary Artery (RCA)

Answer

In a right-dominant circulation (most common), the posterior descending artery (PDA) supplies the inferior wall. The PDA is a branch of the right coronary artery (RCA). Therefore, an occlusion of the RCA is the most common cause of an inferior wall myocardial infarction.

Question 2

What is the intrinsic firing rate of the atrioventricular (AV) node when it acts as the primary pacemaker?

Accepted Answer

40-60 beats per minute

Answer

The cardiac conduction system has a hierarchy of pacemakers. The SA node is the primary pacemaker (60-100 bpm). If it fails, the AV node takes over at its intrinsic rate of 40-60 bpm, resulting in a junctional escape rhythm.

Question 3

In a patient with severe aortic stenosis, what pressure gradient finding is expected during a left heart catheterization?

Accepted Answer

Peak systolic LV pressure is significantly higher than peak systolic Ao pressure

Answer

Aortic stenosis is a narrowing of the aortic valve, which obstructs blood flow from the left ventricle (LV) to the aorta (Ao). To overcome this obstruction, the LV must generate a much higher pressure during systole compared to the pressure in the aorta. This difference is the peak-to-peak or mean pressure gradient across the valve.

Question 4

The Frank-Starling mechanism of the heart describes the relationship between:

Accepted Answer

Preload and stroke volume

Answer

The Frank-Starling law states that the stroke volume of the heart increases in response to an increase in the volume of blood filling the ventricles (the end-diastolic volume). The increased volume stretches the ventricular wall, causing cardiac muscle to contract more forcefully. This relationship is between preload (ventricular stretch/volume) and contractility (stroke volume).

Question 5

During a right heart catheterization for an atrial septal defect (ASD), the most significant oxygen saturation 'step-up' would be found between which two chambers?

Accepted Answer

Superior Vena Cava and Right Atrium

Answer

An ASD allows oxygenated blood from the left atrium to shunt into the right atrium, mixing with deoxygenated systemic venous return. This causes the oxygen saturation of blood in the right atrium to be significantly higher than the blood in the superior and inferior vena cava. This 'step-up' in saturation is the hallmark diagnostic finding for an ASD.

RCIS - Registered Cardiovascular Invasive Specialist Practice Test

RCIS - Registered Cardiovascular Invasive Specialist Practice Test

Free RCIS Cardiovascular Anatomy and Physiology Questions and Answers