MCQ: Cardiovascular System Pathology | MCQ Quiz | OmpathStudy Kenya

Question 1

Which foramen ovale closes in approximately 75% of individuals at birth?

Accepted Answer

Foramen ovale — Closes by fusion of septum primum and secundum. Persists in 25% of adults as PFO.

Question 2

Anatomical closure of the ductus arteriosus occurs through which process?

Accepted Answer

Intimal proliferation and fibrosis — Functional closure via vasoconstriction occurs first. Anatomical closure takes several weeks through intimal proliferation and fibrosis.

Question 3

Failure of which structure to adequately cover the ostium secundum results in ostium secundum ASD?

Accepted Answer

Septum secundum — Ostium secundum ASD occurs when the septum secundum does not enlarge sufficiently to cover the ostium secundum.

Question 4

Which VSD type is specifically more common in Asian patients?

Accepted Answer

Doubly committed subarterial VSD — Situated in the outlet septum, bordered by fibrous continuity of aortic and pulmonary valves.

Question 5

The fundamental embryological defect in Tetralogy of Fallot is:

Accepted Answer

Anterior cephalad deviation of the outlet septum — This single defect produces all four features of TOF — outlet VSD, pulmonary outflow obstruction, overriding aorta and RVH.

Question 6

Which structure, when displaced apically, causes atrialization of the right ventricular inflow tract?

Accepted Answer

Septal leaflet of tricuspid valve — This is Ebstein's anomaly. Apical displacement of the septal tricuspid leaflet causes the RV inflow to function as an atrial chamber.

Question 7

In Transposition of Great Arteries, which embryological failure is directly responsible?

Accepted Answer

Resorption of subpulmonary instead of subaortic conus — Normally the subaortic conus resorbs, moving the aorta posteriorly to connect with the LV. In TGA the wrong conus resorbs, keeping the aorta anterior and connected to the RV.

Question 8

Which chromosomal abnormality is most specifically associated with coarctation of the aorta?

Accepted Answer

Turner syndrome — Turner syndrome is specifically associated with coarctation of aorta and bicuspid aortic valve. Trisomy 21 is associated with AV canal defects.

Question 9

Persistent truncus arteriosus always occurs alongside which other defect?

Accepted Answer

Ventricular septal defect — The single great vessel overrides both ventricles, so a VSD is always present in persistent truncus arteriosus.

Question 10

Sinus venosus ASD is specifically associated with anomalous drainage of pulmonary veins from which lung?

Accepted Answer

Right lung — Right pulmonary veins drain anomalously into the SVC or right atrium due to the proximity of the sinus venosus defect to the SVC entry.

Question 11

Which maternal teratogen is specifically associated with Ebstein's anomaly?

Accepted Answer

Lithium — Maternal lithium use in first trimester is the specific teratogen classically associated with Ebstein's anomaly.

Question 12

A restrictive VSD differs from a non-restrictive VSD in that it:

Accepted Answer

May close spontaneously during childhood — Restrictive VSDs cause no significant haemodynamic derangement and may close spontaneously, unlike large non-restrictive VSDs which cause progressive pulmonary hypertension.

Question 13

Which congenital defect results from failure of both subpulmonary AND subaortic conus to resorb?

Accepted Answer

Double outlet right ventricle — Failure of either conus to resorb produces double outlet anomalies of the RV. TGA results from resorption of the wrong conus. TOF results from malalignment, not failure of resorption.

Question 14

The ostium primum is created during atrial septation by growth of which structure toward the AV canal?

Accepted Answer

Septum primum downward from the roof — The septum primum grows downward creating the ostium primum inferiorly. As it grows, perforations form superiorly creating the ostium secundum.

Question 15

VSD accounts for what percentage of all congenital heart disease?

Accepted Answer

25% — VSD is the most common congenital heart defect overall, accounting for 25% of all CHD.

Question 16

Which component of the ventricular septum lies directly beneath the aortic valve?

Accepted Answer

Membranous septum — The small membranous septum lies just underneath the aortic valve. Membranous VSDs often have inlet, outlet or trabecular extension.

Question 17

In which CHD does the right ventricle inflow tract function haemodynamically as an atrial chamber?

Accepted Answer

Ebstein's anomaly — Apical displacement of the septal tricuspid leaflet causes atrialization of the RV inflow tract — it receives atrial pressure and contracts out of synchrony with the functional RV.

Question 18

Which of the following is the correct sequence of atrial septal development?

Accepted Answer

Septum primum → ostium primum → ostium secundum → septum secundum — Septum primum grows down creating ostium primum. Perforations coalesce into ostium secundum. Then septum secundum develops to the right, leaving the fossa ovalis.

Question 19

Which of the following maternal infections is a recognised cause of congenital heart disease?

Accepted Answer

Rubella — Maternal rubella is a recognised environmental cause of CHD, particularly PDA and pulmonary stenosis. It is specifically listed among the environmental teratogenic causes of CHD.

Question 20

In Tetralogy of Fallot, which level is the dominant site of right ventricular outflow obstruction?

Accepted Answer

Subvalvular (infundibular) — The dominant obstruction in TOF is at the subvalvular/infundibular level due to hypertrophied infundibular myocardium from the malaligned outlet septum — not at the valve itself.

Question 21

Coarctation of the aorta occurs most commonly at which location?

Accepted Answer

Juxtaductal — at the ductus arteriosus insertion — Narrowing occurs just distal to the left subclavian artery at the site of ductus arteriosus insertion.

Question 22

Which radiological finding is specifically associated with coarctation of the aorta?

Accepted Answer

Rib notching — Caused by dilated intercostal collateral vessels eroding the inferior rib margins, developing to bypass the coarctation.

Question 23

A patient with an untreated large VSD develops reversed cyanosis. Which term describes this end-stage complication?

Accepted Answer

Eisenmenger syndrome — Chronic L→R shunting → pulmonary hypertension → pulmonary pressure exceeds systemic → shunt reverses to R→L → cyanosis. This is irreversible.

Question 24

Patent foramen ovale in adults is specifically associated with which cerebrovascular complication?

Accepted Answer

Paradoxical embolism causing cryptogenic stroke — Venous thrombus crosses from right to left atrium through the PFO entering systemic circulation, causing stroke without an obvious arterial source.

Question 25

Ostium primum ASD is associated with a cleft in which specific valve leaflet?

Accepted Answer

Anterior mitral valve leaflet — Both the ostium primum ASD and the cleft mitral leaflet result from the same endocardial cushion maldevelopment. Commonly seen in Down syndrome.

Question 26

Which congenital heart defect is characterised by absence of a direct connection between the right atrium and right ventricle?

Accepted Answer

Tricuspid atresia — There is no tricuspid valve orifice connecting RA to RV. Survival depends on an ASD for right-sided drainage and a VSD or PDA for pulmonary blood flow.

Question 27

Hypoplastic left heart syndrome is more common in which sex?

Accepted Answer

Males — Hypoplastic left heart is among the CHDs more common in males, alongside aortic stenosis, coarctation, pulmonary atresia, tricuspid atresia and TGA.

MCQ: Cardiovascular System Pathology | MCQ Quiz | OmpathStudy Kenya

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