2What we are going to cover… Cardiac embryologySeptal formation: atrial, ventricular and arterial outflowHeart defectsTimeline of cardiac development
3What type of folding moves the brain, mouth and heart into the adult position? And when does this happen?Longitudinal folding. Day 19.Heart is initially situated above the head then through longitudinal folding it moves into the adult positionGreen line = position of the heart
4What is this called? And what is its clinical significance? Transverse pericardial sinusSits between arterial outflow & venous inputSignificance: clamp off arterial flow during surgery.
6Dilations appear in the heart tube. Name them… Left HornOf SinusRight HornOf sinusSinus VenosusBulbus CordisTruncus ArteriosusAortic sacAtriaVentricleSmooth wall of right atriaRough wall of both atriaVentriclesMainly outflow of ventriclesInitial part of aorta & pulmonary trunk
7And then what happens?Pulmonary veins grow out of the left atrial wall and branch. The proximal parts get absorbed into the atrial wall = smooth partCoronary sinusVena CavaeLALVOutflowAortaRARAOutflowPulm TrunkRVSeptum between left and right sides of the heart.Septa form and divide chambers and outflow tract to create the left right sides of the heart
8Shunting takes place to avoid the developing lungs Shunting takes place to avoid the developing lungs. Which direction does this happen in?Coronary sinusVena CavaeLALVOutflowAortaRARARVOutflowPulm TrunkR L shunting
9What is this called?TABCVNormalASVDextrocardiaDextrocardia
11Atrial Septum Septum primum RA LA Foramen primum Endocardial cushion Foramen secundumRALASeptum secundumRALAEndocardinal cushion grow across the AV canal from anterior to posterior.The cushion is a swelling in mesenchyme.Septum secundumRALAValve of Foramen ovaleForamen ovale
12What is the function of the foramen ovale in the fetus? Lungs are fluid filled with high pulmonary resistance.Want to avoid themTherefore blood is shunted through the foramen ovale from R LAs soon as they take their first breathe the foramen ovale closes as the pressure changes.RALAThe septum secundum is muscular and stiffThe septum primum is relatively floppy – it acts as a valve cusp
13Sometimes fusion of foramen ovale does not occur Sometimes fusion of foramen ovale does not occur. What problems could this cause in later life?Valsava maneuver can briefly increase right sided pressure over leftThis opens the foramen ovaleCan result in emboli passing from right atria to left atriaIncreases possibility of TIA and stroke.Test using micro bubble test (ultrasound).
14Ventricular Septum. Day 35-42. What three things come together to form the ventricular septum?Muscle, membrane and endocardial cushionWhich of these three parts is most likely to go wrong?Two membranous ridges grow downMembranous partEndocardial cushionMuscular septum
15Common ventricular outflow septum. Day 35. A PAPWhat are the ridges derived from?Septum forms in truncus arteriosus and bulbus cordisNeural crest mesenchymeSeptum spirals through ____o creating the aorta and the pulmonary trunk180
16Name all the defects.. Defects Which ones are cyanotic? Truncus arteriosusVentricular septalTetraology of fallotAtrial septalTransposition the great vesselsCritical pulmonary stenosisPatent ductus arteriosusWhich ones are cyanotic?To be coloured blue or red