CCS CCS Cardiac Anatomy and Physiology 2 — Questions and Answers
Question 1: In right heart dominance, the posterior descending artery (PDA) originates from which vessel?
- Left anterior descending artery
- Left circumflex artery
- Right coronary artery (Correct answer)
- Left main coronary artery
Correct answer: Right coronary artery
In right heart dominance (~85% of patients), the PDA arises from the right coronary artery, supplying the inferior interventricular septum.
Question 2: The Frank-Starling law of the heart describes which relationship?
- Heart rate and blood pressure
- Ventricular preload and stroke volume (Correct answer)
- Afterload and cardiac output
- Contractility and oxygen consumption
Correct answer: Ventricular preload and stroke volume
The Frank-Starling law states that increased ventricular filling (preload) stretches myocardial fibers, resulting in greater stroke volume.
Question 3: Which of the four cardiac valves is located most anteriorly in the chest?
- Mitral valve
- Tricuspid valve
- Pulmonary valve (Correct answer)
- Aortic valve
Correct answer: Pulmonary valve
The pulmonary valve is the most anteriorly positioned valve, located at the right ventricular outflow tract just beneath the sternum.
Question 4: Ventricular end-diastolic pressure (VEDP) is used clinically as a surrogate for which cardiac parameter?
- Afterload
- Contractility
- Preload (Correct answer)
- Heart rate
Correct answer: Preload
VEDP reflects the volume of blood in the ventricle at end-diastole and is used as a clinical measure of preload.
Question 5: Which structure forms the muscular partition between the right and left ventricles?
- Atrial septum
- Interventricular septum (Correct answer)
- Crista terminalis
- Moderator band
Correct answer: Interventricular septum
The interventricular septum divides the right and left ventricles and is predominantly supplied by the LAD artery.
Question 6: Normal left ventricular ejection fraction (LVEF) in a healthy adult is approximately which range?
- 25–40%
- 40–50%
- 55–70% (Correct answer)
- 75–90%
Correct answer: 55–70%
A normal LVEF is 55–70%, indicating that the left ventricle ejects over half its end-diastolic volume with each beat.
CCS CCS Cardiac Anatomy and Physiology 2
In right heart dominance, the posterior descending artery (PDA) originates from which vessel?