NBME CBSE QUESTIONS AND
DETAILED ANSWERS
,Bulbus cordis - CORRECT ANS:Smooth parts (outflow tract) of left and right ventricles
endocardial cushions - CORRECT ANS:Atrial septum, membranous interventricular septum; AV and
semilunar valves
neural crest
left horn of the sinus venosus - CORRECT ANS:coronary sinus
posterior, sub cardinal, and supra cardinal veins - CORRECT ANS:IVC
Right common cardinal vein and right anterior cardinal vein - CORRECT ANS:SVC
Right horn of sinus venosus - CORRECT ANS:Smooth part of right atrium (sinus venarum)
Patent foramen ovale - CORRECT ANS:failure of septum primum and septum secundum to fuse after
birth
Transposition of the great vessels
Tetralogy of Fallot
Persistent truncus arteriosus - CORRECT ANS:Conotruncal abnormalities associated with failure of neural
crest cells to migrate
ductus venosus - CORRECT ANS:connects the umbilical vein to the inferior vena cava, bypassing the liver
becomes ligamentum venosum
,phrenic nerve - CORRECT ANS:innervates the diaphragm and pericardium
S3 heart sound - CORRECT ANS:Increased ventricular filling pressure (e.g., mitral regurgitation, HF),
common in dilated ventricles
normal in kids and pregnant women
S4 heart sound - CORRECT ANS:atrial kick late diastole, right before S1
best heard at apex in LLD position
High atrial pressure.
Stiff/hypertrophic ventricle (aortic stenosis, restrictive cardiomyopathy)
Always abnormal
atria contract - CORRECT ANS:a wave of JVP
c wave - CORRECT ANS:RV contraction (closed tricuspid valve bulging into atrium) wave of JVP
x descent - CORRECT ANS:JVP wave corresponding to downward displacement of closed tricuspid valve
during rapid ventricular ejection phase
reduced or absent in tricuspid regurge
, V wave - CORRECT ANS:JVP wave corresponding to inc'd RA pressure due to filling against closed
tricuspid valve
y descent - CORRECT ANS:JVP wave corresponding to RA emptying into RV
absent in cardiac tamponade
plusus parvus et tardus - CORRECT ANS:pulses are weak with delayed peak
Aortic stenosis
PR interval - CORRECT ANS:0.12-0.20 seconds
120 milliseconds
QT interval length - CORRECT ANS:9 - 11 squares = .36 to .44 seconds
Hypokalemia - CORRECT ANS:U wave present on ECG
Mg sulfate - CORRECT ANS:for torsades de pointe, hypokalemia (can lengthen QT and cause torsades),
and pre-eclampsia (prevent seizures)
Romano-Ward syndrome - CORRECT ANS:-Congenital long QT syndrome
-Autosomal dominant, pure cardiac phenotype (no deafness).
Jervell and Lange-Nielsen syndrome - CORRECT ANS:-Congenital long QT syndrome
DETAILED ANSWERS
,Bulbus cordis - CORRECT ANS:Smooth parts (outflow tract) of left and right ventricles
endocardial cushions - CORRECT ANS:Atrial septum, membranous interventricular septum; AV and
semilunar valves
neural crest
left horn of the sinus venosus - CORRECT ANS:coronary sinus
posterior, sub cardinal, and supra cardinal veins - CORRECT ANS:IVC
Right common cardinal vein and right anterior cardinal vein - CORRECT ANS:SVC
Right horn of sinus venosus - CORRECT ANS:Smooth part of right atrium (sinus venarum)
Patent foramen ovale - CORRECT ANS:failure of septum primum and septum secundum to fuse after
birth
Transposition of the great vessels
Tetralogy of Fallot
Persistent truncus arteriosus - CORRECT ANS:Conotruncal abnormalities associated with failure of neural
crest cells to migrate
ductus venosus - CORRECT ANS:connects the umbilical vein to the inferior vena cava, bypassing the liver
becomes ligamentum venosum
,phrenic nerve - CORRECT ANS:innervates the diaphragm and pericardium
S3 heart sound - CORRECT ANS:Increased ventricular filling pressure (e.g., mitral regurgitation, HF),
common in dilated ventricles
normal in kids and pregnant women
S4 heart sound - CORRECT ANS:atrial kick late diastole, right before S1
best heard at apex in LLD position
High atrial pressure.
Stiff/hypertrophic ventricle (aortic stenosis, restrictive cardiomyopathy)
Always abnormal
atria contract - CORRECT ANS:a wave of JVP
c wave - CORRECT ANS:RV contraction (closed tricuspid valve bulging into atrium) wave of JVP
x descent - CORRECT ANS:JVP wave corresponding to downward displacement of closed tricuspid valve
during rapid ventricular ejection phase
reduced or absent in tricuspid regurge
, V wave - CORRECT ANS:JVP wave corresponding to inc'd RA pressure due to filling against closed
tricuspid valve
y descent - CORRECT ANS:JVP wave corresponding to RA emptying into RV
absent in cardiac tamponade
plusus parvus et tardus - CORRECT ANS:pulses are weak with delayed peak
Aortic stenosis
PR interval - CORRECT ANS:0.12-0.20 seconds
120 milliseconds
QT interval length - CORRECT ANS:9 - 11 squares = .36 to .44 seconds
Hypokalemia - CORRECT ANS:U wave present on ECG
Mg sulfate - CORRECT ANS:for torsades de pointe, hypokalemia (can lengthen QT and cause torsades),
and pre-eclampsia (prevent seizures)
Romano-Ward syndrome - CORRECT ANS:-Congenital long QT syndrome
-Autosomal dominant, pure cardiac phenotype (no deafness).
Jervell and Lange-Nielsen syndrome - CORRECT ANS:-Congenital long QT syndrome
