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Cardiac Embryology Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

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Page 1: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Cardiac Embryology

Adel Mohamad Alansary, MDAss. Prof. Anesthesiology and Critical Care

Ain Shams University

Page 2: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

The beginning

Page 3: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Function of each Layer

Endocardium: Endothelial lining ,Connective tissue precursor (Valves and fibrous skeleton).

 Myocardium: Myocytes, Conduction system (Purkinje fibres),Myoendocrine cells (Atrial Natriuretic Factor production)

Epicardium Coronary vessel precursors, Visceral pericardial lining.

Page 4: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

The beginning Two lateral extensions of

cardiac tissue become hollowed out to form a pair of endothelial tubes, which soon fuse to form the primitive cardiac tube.

Paired veins from the trunk (the cardinal system), liver, yolk sac and placenta enter the heart tube from below and a series of arterial arches emerge from the upper end.

Page 5: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

HEART TUBE

Page 6: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

the sinus venosus

the atrium

the ventricle

bulbus cordis

arterial trunk

Page 7: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Looping

Page 8: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Looping

Page 9: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Looping

Page 10: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

• The fold of the loop is principally at the junction of bulbus cordis and ventricle. Note in panel C that the two end up side by side.

Page 11: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Formation of the Cardiac Loop

28 days

• Atrium grows dorsally to the left• Ventricle & bulbus cordis grows ventrally & to the right

Page 12: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

30 days

At the end of the loop formation

Page 13: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

normal d-loop l-loop

Page 14: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Abnormalities of Heart Position

Dextrocardia : cardiac loop to the left.= Heart in the right thorax associated with situs inversus (transposition of the viscera)

Ectopia cordis= Heart on the surface of chest caused by failure to close the midline

Page 15: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

ENDOCARDIAL CUSION FUSION

Page 16: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University
Page 17: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Formation of Ventricular Septum1. Growth of Endocardial cushions

Page 18: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Septum Formation in A-V Canal

Page 19: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Valve formation

Page 20: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University
Page 21: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Valve Atresia

Page 22: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Tricuspid Atresia

Page 23: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

ATRIAL SEPTUM

Page 24: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Interatrial Septum

Page 25: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Interatrial Septum

Page 26: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

ASD

Secundum type defects are observed in 80% of cases. These are characterized by defects involving the foramen ovale and (usually) a defect in the septum primum.

Sinus venosus defects are usually positioned near the entrance of the superior vena cava. These are generally associated with anomalous entry of the right superior pulmonary vein.

Page 27: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

ASD

Ostium primum defects are very similar to defects caused by failure of endocardial cushion fusion.

Rarely, complete agenesis of the septum occurs, giving a common atrium.

Page 28: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

VENTRICULAR SEPTUM

Page 29: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Interventricular Septum

Page 30: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

VSD

Type I defects are positioned in the infundibulum of the right ventricle, caudal to the pulmonary valve. These arise from defects in the formation of the bulbus cordis and truncus arteriosus. These are also referred to as supracristal, conal or infundibular VSD.

Page 31: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

VSD

Type II defects occur in the membranous portion of the septum, and are the most commonly observed defects. These are also referred to as paramembranous VSD.

Page 32: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University
Page 33: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

VSD

Type III defects are found in close proximity to the tricuspid valve, within the inlet of the right ventricle. These are thought to arise from defects in the partitioning of the AV canal by the endocardial cushions. Also identified as atrioventricular canal defects or inlet defects.

Page 34: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

VSD

Type IV defects are present in the muscular portion of the interventricular septum. These can be single or multiple, showing extremely irregular borders (variable in many planes). Type IV defects are not easily visualized or repaired.

Page 35: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

GREAT ARTERIES

Page 36: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Arterial Trunk This structure does truly septate,but

embryologically it is a simple coronal division in its embryonic straight position.

The septation extends upwards from the valves to end just beyond the origin of the paired sixth aortic arches, where it seals off against the posterior truncal wall.

As the sixth arch vessels are destined to be the branch pulmonary arteries, the posterior channel is now the main pulmonary artery. The anterior channel is the aorta.

Page 37: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University
Page 38: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

RPA = right pulmonary arteryLPA = left pulmonary arteryAPS = aortopulmonary (truncal) septumRVO = RV outflowLVO = LV outflow

And so now you can compare the flow scheme on the left with the more lifelike imageon the right

Page 39: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University
Page 40: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Fate of Truncus Arteriosus & Aortic Sac

FateStructureLef t Right

TruncusArteriosus

Root ofPulmonary Trunk(proximal)

Root of Aorta(proximal)

Aortic sac Brachiocephalicartery

Arch of Aorta(proximal)

Page 41: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Fate of Aortic ArchesFateStructure

Right Left

1st Aortic arches Maxillary a. Maxillary a.

2nd Aortic arches Hyoid a. &Stapedial a.

Hyoid a. &Stapedial a.

3rd Aortic arches 1. Common carotida.

2. I nternal carotida. (proximal)

3. External carotida.

1. Common carotida.

2. I nternal carotida. (proximal)

3. External carotida.

Page 42: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

FateStructure

Right Left

4th Aortic arches Subclavian a. Arch of Aorta &Subclavian a.

5th Aortic arches - -

6th Aortic arches Right Pulmonarya.

Ductusarteriosus & LeftPulmonary a.

Fate of Aortic Arches

Page 43: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Tetralogy of Fallot

Page 44: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Patent Ductus Arteriosus

Page 45: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Questions

the truncal septum fails to fuse with the septal crest?

- perimembraneous VSD the truncal septum is deviated to the PA side? - tetralogy of Fallot the truncal septum fails to develop? - truncus arteriosus the ventricular septum fails to reach the AV valve? - AV septal defects

Page 46: Adel Mohamad Alansary, MD Ass. Prof. Anesthesiology and Critical Care Ain Shams University

Questions

the arterial trunk stays over the RV but does divide?

- double outlet RV the aortic valve pushes up and right instead of

the pulmonary? - transposition of the great vessels the ventricles fail to centralise over the AV valve - double inlet left ventricle (commonest

form of single ventricle.