Cardiology - Embryo and Anatomy

ekadar's version from 2015-09-06 10:26


Question Answer
Fetal alcohol syndromeVSD, ASD, tetralogy of fallot
22Q11DiGeorge: Persistent truncus arteriosus, Tetralogy of fallot
Pregestational maternal diabetesPersistent Truncus arteriosus
Congenital rubellaPDA
Down's syndromeASD > VSD
Turner'sCoarctation of the aorta (infantile)
L → R ShuntsAcyanotic LateR: VSD > ASD > PDA
MC congenital heart defectVSD [fetal alcohol syndrome]
How do you close a PDA?Indamethacin
Ostium secundum defectsASD
Wide fixed split S2ASD
Cause of paradoxical embolusUsually ASD
PDADuctus arteriosus fails to close [congenital rubella]
Continuous holosystolic machine-like murmurPDA
Coarctation of the aortanarrowed aorta: infantile comes before the arch, adult comes after the arch
Rib notchingCoarctation of teh aorta:
R → L ShuntsBlue babies:
1. Persistant truncus arteriosus
2. Transposition of the great vessels
3. Tricuspid atresia
4. Tetralogy of Fallot
5. Total anomalous pulmonary venous return
Blood from the RV → Pulmonary artery and aortaTruncus arteriosus fails to divide
Separate pulmonary and systemic systemsTransposition of the great vessels [pre-gestational diabetes]
Rx for transposition of great vesselsPGE to kEEp the ductus arteriosus open until surgery
Tetralogy of FallotPulmonary stenosis
Right ventricle hypertrophy
Overriding aorta
SquattingTetralogy of Fallot: ↑ PVR: ↑afterload ↓ cyanotic R→L shunt
Cause of Tetralogy of FallotAnteriosuperior displacement of the infundibular septum
- Abnormal neural crest cell migration
Tricuspid atresiaAbsent tricuspid valve + hypoplastic RV
MC cause of childhood cyanosisTetralogy of Fallot
Total anomalous pulmonary venous returnPulmonary veins drain into right heart
Boot shaped heartTetralogy of fallot
What congenital heart defects are caused by abnormal migration of neural crest cells?Truncus arteriosus
Truncus arteriosus
Tetralogy of Fallot
Severity of Tetralogy of Fallot is determined byDegree of pulmonic stenosis
Degree of RV outflow obstruction affects pressure and therefore direction of shunt


Embryonic structureGives rise to
Truncus arteriosus (TA)Spirals up to yield ascending aorta and pulmonary trunk
Bulbus cordisSmooth parts (outflow tract) of left and right ventricles
PRimitive ventricleTrabeculated left and right ventricles
Primitive atriaTrabeculated left and right atria
Left horn of sinus venosusCoronary sinus
Right horn of sinus venosusSmooth part of right atrium
Right common cardinal vein and right anterior cardinal veinSVC
Patent foramen ovalecaused by failure of septum primum and septum secundum to fuse after birth
Fetal erythropoiesis occurs where?"Young Liver Synthesizes Blood"
Yolk sac (3-8 wk)
Liver (6 wk-birth)
Spleen (10-28 wk)
Bone marrow (18wk - adult)
Fetal hemoglobinalpha2gamma2
Adult hemoglobinalpha2beta2
PO2 of umbilical vein vs. arteryvein=30 mmHg (80% SaO2)
Shunt to bypass hepatic circulationDuctus venosus
Umbilical vein → IVC
Shunt to bypass lungsforamen ovale
Shunt to catch the rest of the blood that the foramen ovale misses and avoid the lungsDuctus arteriosus
Pulmonary artery→Descending aorta
What closes PDA? Opens it?Indomethacin closes PDA
Prostaglandins E1 and E2 keep it open
Umbilical vein becomesLegamentum teres hepatis
(Contained in falciform ligament)
Umbilical arteries becomeMedial umbilical ligaments
Ductus arteriosus becomesLigamentum arteriosum
Ductus venosus becomesLigamentum venosum
Foramen ovale becomesFossa ovalis
Allantois becomesUrachus-median umbilical ligament
(Urachus=part of allantoic duct from bladder to umbilicus)
Notochord becomesNucleus pulposus of intervertebral disc
VSD most commonly inmembranous septum
aortic/pulmonic valves derived fromendocardial cushions of outflow tract
mitral/tricuspid valves derived fromendocardial cushions of AV valve

What happened in embryo to cause these defects

Question Answer
abnormal leftward looping of primitive hearttransposition of great arteries
failed fusion of endocardial cushionsatrial defects or VSDS
deviation of infundibular septumTOF
Mnemonic for TOFPROVe. Pulmonary Hypertension, RVH, Overriding aorta, VSD


Question Answer
SA and AV node supplied byRCA
Right-dominant circulation and posterior descending artery (PD)85% - PD arises from right coronary artery
Left dominant circulation8% - PD arises from Left circumflex artery
LCA to circumflex to PDA
Codominant circulation7% - PD arises from both left circumflex artery and RCA
Coronary artery occlusion most commonly occurs in theLAD
When do coronary arteries fill?Diastole
Most posterior part of heartLeft atrium
Enlargement of the most posterior part of the heart (left atrium) can causedysphagia (compression of esophagus)
hoarseness (compression of left recurrent laryngeal nerve - a vagus branch)
LAD occlusionst elevations in V1-V4
RCA occlusion ischemia of inferior wallST elevation in II, III, and avF
LCX occlusionsST elevations in V5-V6 and I, aVL
inferior wall MIII, III, aVF, RCA
posterior wall MIleft circumflex
lateral wall MII, aVL, V5, V6, left circumflex
anterioseptal wall or septal wall MILAD