NBME CBSE

Bulbus cordis –

Smooth parts (outflow tract) of left and right ventricles

endocardial cushions –

Atrial septum, membranous interventricular septum; AV and semilunar valves

neural crest

left horn of the sinus venosus –

coronary sinus

posterior, sub cardinal, and supra cardinal veins –

IVC

Right common cardinal vein and right anterior cardinal vein –

SVC

Right horn of sinus venosus –

Smooth part of right atrium (sinus venarum)

Patent foramen ovale –

failure of septum primum and septum secundum to fuse after birth

Transposition of the great vessels

Tetralogy of Fallot

Persistent truncus arteriosus –

Conotruncal abnormalities associated with failure of neural crest cells to migrate

ductus venosus –

connects the umbilical vein to the inferior vena cava, bypassing the liver

becomes ligamentum venosum

phrenic nerve –

innervates the diaphragm and pericardium

S3 heart sound –

Increased ventricular filling pressure (e.g., mitral regurgitation, HF), common in

dilated ventricles

normal in kids and pregnant women

S4 heart sound –

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 –

a wave of JVP

c wave –

RV contraction (closed tricuspid valve bulging into atrium) wave of JVP

x descent –

JVP wave corresponding to downward displacement of closed tricuspid valve

during rapid ventricular ejection phase

reduced or absent in tricuspid regurge

V wave –

JVP wave corresponding to inc'd RA pressure due to filling against closed

tricuspid valve

y descent –

JVP wave corresponding to RA emptying into RV

absent in cardiac tamponade

plusus parvus et tardus –

pulses are weak with delayed peak

Aortic stenosis

PR interval –

0.12-0.20 seconds

120 milliseconds

QT interval length –

9 - 11 squares = .36 to .44 seconds