NBME CBSE, ANSWERED-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 h
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NBME CBSE, ANSWERED-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
Hypokalemia - U wave present on ECG
Mg sulfate - for torsades de pointe, hypokalemia (can lengthen QT and cause torsades), and pre-eclampsia (prevent seizures)
Romano-Ward syndrome - -Congenital long QT syndrome
-Autosomal dominant, pure cardiac phenotype (no deafness).
Jervell and Lange-Nielsen syndrome - -Congenital long QT syndrome
-Autosomal recessive, sensorineural deafness
Brugada syndrome - -Autosomal dominant disorder affecting Na channels most common in Asian males.
-ECG pattern of pseudo-right bundle branch block and ST elevations in V1-V3 (anterior ventricular septum)
-inc risk of ventricular tachyarrhythmias and sudden cardiac deatgh
Prevent SCD with implantable cardioverter-defibrillator (ICD).
Wolff-Parkinson-White Syndrome - Most common type of ventriuclar pre-excitation sydnrome. Abnormal fast accessory conduction pathway from atria to venricle bypasses the rate-slowing AV node causing a delta wave and widening QRS with shortened PR interval. Could lead to a reentrant circuit and suprvaventicular tachy.
First degree AV block - - PRI >5 boxes/.20 sec (200 msec)
- Fixed but prolonged PRI
(consistent but long)
- normally get bradycardia here
second degree AV block mobitz type 2 - -PR interval is constant
-atrial conduction to ventricle is intermittent: dropped QRS without increasing PR interval length
-disease below AV node in His bundle
may progress to 3rd degree/complete AV block
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