Echocardiography

[Audio] E M B R Y O L O G Y The cardiovascular system is the first organ to reach a functional state. The most sensitive period for cardiac development is 3 to 6 weeks By the end of the 4th week, circulation of blood has begun and the heart begins to beat. At about 22 days the primitive heart begins to beat(swishing) Between 33-37 days septation begins At 43 days the fetal heart is developed into a complete complex structure..

[Audio] A pair of heart tubes are formed early in embryonic cardiovascular development The tubes lie parallel to each other and towards the head (cephalad) of the fetus. These tubes will fuse together forming a single heart tube (this occurs by day 22) The single heart tube will consist of An external myocardial mantle and an internal mantle Layers of the Primitive Heart Tube o From inside → outside:  Endocardium → inner lining of the heart  Cardiac jelly → gelatin-like middle layer (helps cushion and shape)  Myocardium → muscular outer layer that will become the heart muscle Around day 22–23, the heart begins to beat! By the 4th week, blood is already circulating through the embryo..

[Audio] F O R M AT I O N O F H E A R T L O O P. F O R M AT I O N O F H E A R T L O O P.

[Audio] The "looping" step By day 23, the tube is too long for the tiny pericardial cavity. So, it bends and loops into a U-shape. By day 28, the loop points forward and to the right. This looping is important because it places the atria behind and above the ventricles (like in the normal adult heart). At this stage, there are no walls yet between chambers, and no valves. The atrium connects to the ventricle through one passage called the atrioventricular (AV) canal. Later, this AV canal splits into two passages → one for the tricuspid valve (right side) and one for the mitral valve (left side)..

[Audio] S I N U S V E N O S U S Consists of 2 horns right and left which eventually will contribute to the formation of the SVC, IVS, CS and the posterior wall of the atria. The distal portion of the left horn usually dissipated Sinus Venosus Left Horn  Forms coronary sinus Sinus Venosus Right Horn  Right horn becomes absorbed into the right atria as the sinus venarum.

[Audio] D E V E L O P M E N T O F T H E H E A R T Primitive atrium: develops into the right and left atria Primitive ventricle: develops into the left ventricle. Bulbus Cordis - develops into the right ventricle Conus: develops into the crista supraventricular Truncus arteriosus: dilates to form the aortic sac from which the aortic arches arise. It develops into the aorta and pulmonic valves. 5 / 1 2 / 2 0 2 6 6.

[Audio] S E P TAT I O N O F T H E AT R I A S During the fourth and fifth weeks of fetal development, the division of the four chambers occurs. 1. Septum Primum forms o A thin wall called the septum primum grows downward from the roof of the atrium. o At first, it doesn't reach the bottom → leaving a hole called the ostium primum 2. Ostium Primum closes, but Ostium Secundum forms o The septum primum eventually reaches the bottom and closes the ostium primum. o But before it fully seals, small holes open higher up in the septum primum. o These holes join to form a new opening called the ostium secundum, which keeps blood flowing between the atria..

[Audio] 3. Septum Secundum forms o A second, thicker wall called the septum secundum grows down next to the first wall. o It partly covers the ostium secundum, but doesn't close it completely. o This leaves a new oval-shaped hole → the foramen ovale. o 4. Valve of the foramen ovale o The lower edge of the septum primum now acts like a flap valve. o It lets blood pass one way only → from the right atrium to the left atrium. o This is important in fetal life, because it allows blood to bypass the lungs, which aren't working yet..

Ostium primum Septum secundum Interventricular-- foramen c Septum secundum Septum primum Endocardial cushion Septum secundum Foramen Septum primum Muscular interventricular septum D Ostium secundum -— Interventricular foramen Ostium secundum Septum primum Membranous interventricular septum.

[Audio] AfterbirthoOncethebabyisborn,pressureintheleftatriumbecomeshigherthanintheright(becauselungsareworking).oThispressurepushestheflapoftheseptumprimumagainsttheseptumsecundum,closingtheforamenovale.oEventually,itsealsandbecomesthefossaovalis..

[Audio] Septation of the Atrioventricular Canal 1. Endocardial cushions form Inside the early AV canal, small swellings of soft tissue appear. These are called endocardial cushions. 2. Cells move in and change Cells from the heart's inner lining (endocardium) move into these cushions. They change into a stronger type of tissue that can build structure. 3. Cushions grow and meet The top, bottom, and side cushions all grow in and fuse together. 4. Result: Two canals The single AV canal is now divided into two separate canals:  Right AV canal → will become the tricuspid valve opening  Left AV canal → will become the mitral valve opening.

[Audio] S E P TAT I O N O F T H E V E N T R I C L E S A N D O U T F L O W T R A C T S 1. Starting point (end of week 4) The primitive ventricle grows and a ridge of muscle forms in the middle → this is the primitive interventricular septum (future wall between right and left ventricles). At first, this ridge mostly gets taller because the ventricles on each side are expanding (dilating), not because the ridge itself is growing. 2. The interventricular foramen (the "gap") The top edge of this muscle wall does not reach the endocardial cushions right away. Leaving an opening between the right and left ventricles called the interventricular foramen. At this stage, blood can still move freely between RV and LV. 3. Closing the gap By the end of the 7th week, new tissue grows in from:  The right and left bulbar ridges (tissue around the outflow tracts)  The endocardial cushions (tissue in the AV canal) These tissues fuse with the muscular septum → forming the membranous part of the interventricular septum. This closes the interventricular foramen and fully separates the right and left ventricles..

[Audio] S E P T A T I O N O F T H E V E N T R I C L E S A N D O U T F L O W T R A C T S.

[Audio] A O R T I C A R C H F O R M AT I O N At 4 weeks There are 6 pairs of aortic arches not all at the same time and their functions vary 3rd persists to become origin of ICA 4th persists to become aortic arch 6th persists to become origin of pulmonary arteries 1, 2nd, 5th get absorbed.

[Audio] A O R T I C O P U L M O N A R Y S E P T A T I O N O F T H E T R U N C U S A R T E R I O S U S I N T O T H E A O R T A A N D P U L M O N A R Y A R T E R Y . In the 5th week of development, inside the bulbus cordis and truncus arteriosus (the upper part of the primitive heart tube that will become the great arteries). What forms Special cells (from neural crest) create two tissue ridges called the bulbar ridges. These ridges grow toward each other and fuse in the middle. The spiral twist As they fuse, the ridges twist around each other in a 180° spiral. This spiral wall is called the aorticopulmonary septum. Result The septum splits the single tube into two separate channels:  Pulmonary artery → connects to the right ventricle  Aorta → connects to the left ventricle.

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[Audio] DEVELOPMENTOFTHE HEARTVALVES Therearetwomaingroups:oSemilunarvalves:Aortic&PulmonaryoAtrioventricular(AV)valves:Mitral&Tricuspid 1.SemilunarValves(Aortic&Pulmonary)oTheseformjustbeforetheaorticopulmonaryseptumisfinished.oBloodflowandprogrammedcelldeath(cellsdisappearingwheretheyaren'tneeded)sculpttheselumpsintothreethincusps.oResult:theaorticvalveandpulmonaryvalve,eachwiththreecusps(leaflets)..

[Audio] D E V E L O P M E N T O F T H E H E A R T VA LV E S ( C O N T ) 2. Atrioventricular Valves (Mitral & Tricuspid) o After the endocardial cushions split the AV canal into right and left sides, more tissue grows around each opening. o At first, the leaflets are connected to the ventricular wall by muscular strands. o Over time, the upper parts of these strands disappear and are replaced by thin, strong connective tissue strings → the chordae tendineae. o The chordae attach to papillary muscles, preventing the valves from flipping backward during heart contraction..

[Audio] E M B R Y O L O G Y -The fetal lungs are collapsed and have high vascular resistance. -Oxygenation occurs in the placenta. -Some of the blood passes through the fetus's liver and some goes through IVC via the ductus Venosus. -From the IVC saturated blood enters the right atrium where it is mixed with desaturated blood that is returning from the superior vena cava -The right atrium directs saturated blood through the foramen ovale into the left atrium -A small percent will cross over the TV and enter the RV and will be ejected through the pulmonary artery -Some of the blood goes to the lungs. The Majority is shunted to the descending Aorta through the ductus arteriosus. There are three shunts that are present in fetal circulation. After birth they cease to exist.

[Audio] F E TA L H E A R T C I R C U L AT I O N 1. umbilical vein- vein brings blood to the fetus oxygenated there is one vein and two arteries, the arteries are deoxygenated ( opposite in adults) 2. ductus venosus- ( 1st fetal shunt) avoiding flow through the liver 3. IVC.

[Audio] F E TA L H E A R T C I R C U L AT I O N 4. RA- O2 is increased- flow is directed to the foramen ovale by the eustacian valve over the IVC 5. foramen ovale- ( 2nd fetal shunt) right to left follows the MV to LV to AO 6. TV- some IVC blood goes into the RA and follow the regular path with SVC and CS through the TV.

[Audio] F E TA L H E A R T C I R C U L AT I O N 7. RV 8. PV 9. MPA.

[Audio] F E TA L H E A R T C I R C U L AT I O N 10. fetal lungs are collapsed! Therefore, there is high resistance to blood flow coming into the vascular beds in the lungs. Only very little blood goes into the pulmonary vascular beds at this time. The blood flow that went to the lungs goes to the LA-MV-LV-aorta. Most gets shunted out.

[Audio] F E TA L H E A R T C I R C U L AT I O N 11. Ductus arteriosus- ( 3rd fetal shunt) right to left bypasses the lungs and goes into descending aorta. 12. umbilical arteries carry deoxygenated blood back to placenta to begin the process again..

[Audio] F E TA L H E A R T C I R C U L AT I O N #1 Umbilical vein – ductus venosus - IVC – RA – foramen ovale (LA-MV-LV-Aorta) some will go #2from IVC,SVC and CS-RA – TV – RV – PV – MPA – ductus arteriosus – Aorta Understand there are two ways for blood to travel through the system https://youtu.be/-IRkisEtzsk.

Superior ve cava Lung Fora Right n ovale rium Inferior vena cava Right hepatic vein Portal vein Umbilical vein Umbilicus Umbilical arteries Left hepatic vein Urinary bladder Legs Arch aorta Ductus rte Pulmon trunk Pulmona veins Left atrium Ductus venosus Descending aorta Oxygen saturation of blood: High Medium Internal iliac.

[Audio] BIRTH Afterbirth:lungsstartworking,placentaiscutoff The3fetalshunts—(ductusvenosus,foramenovale,andductusarteriosus)arenolongerneededandbegintoclose. PressureChangesintheHeart Bloodfromlungsincreasespressureintheleftatrium. Atthesametime,cuttingthecordlowersbloodreturningtotherightatrium. Resultinginleftatrialpressurebecomeshigherthantherightatrialpressurethispushestheforamenovaleshut. (Ifitdoesn'tclose→patentforamenovale,PFO). https://youtu.be/jFn0dyU5wUw.

[Audio] T H R E E S H U N T S B E C O M E Fetal Adult Foramen Ovale Fossa Ovalis Ductus Arteriosus Ligamentum arteriosum forms the aorta and pulmonary artery Ductus Venosus (Ligamentum Venosum) after birth it constricts and blood entering liver will pass through the hepatics.

[Audio] T H R E E S H U N T S 1. Ductus Venosus- becomes the Ligamentum Venosum Runs within the liver and joins the umbilical vein with the inferior vena cava. Before birth it carries highly oxygenated blood from the placenta to the fetal circulation. 2. Foramen Ovale- becomes the Fossa Ovalis in adult 3. Ductus Arteriosus- becomes ligamentum Arteriosum (located between the pulmonary and aortic The ductus allows blood to detour away from the lungs before birth, connecting the trunk of the pulmonary artery to the proximal descending aorta. It allows most of the blood from the right ventricle to bypass the fetus's fluid-filled non-functioning lungs. Upon closure at birth, it becomes the ligamentum arteriosum.

[Audio] P R E S S U R E S The left side of the heart has higher pressure therefore; blood is shunted from left to right (high pressure to low pressure) Uncomplicated ASD, VSD's after birth will shunt left to right Results in eventual higher pressure on the right side instead of left 5 / 1 2 / 2 0 2 6 3 0.

[Audio] C O N G E N I TA L D E F E C T S Atrial Septal Defects 3 Types Ostium primum Lower part of the septum by AV valves Ostium secundum Central part of the septum Sinus venosus Superior interatrial septum.

[Audio] A S D 3 T Y P E S. A S D 3 T Y P E S.

[Audio] A S D : O S T I U M P R I M U M. A S D : O S T I U M P R I M U M.

[Audio] A S D : O S T I U M S E C U N D U M. A S D : O S T I U M S E C U N D U M.

[Audio] A S D S I N U S V E N O S U S. A S D S I N U S V E N O S U S.

[Audio] V S D 4 types of VSD; these defects are named based on their anatomic location within the IVS. Perimembranous Most Common Membraneous portion of IVS by AOV Inlet By TV Subarterial Below AOV and PV Muscular Can have many in muscular septum.

[Audio] P E R I M E M B R A N O U S V S D. P E R I M E M B R A N O U S V S D.

[Audio] I N L E T V S D. I N L E T V S D.

[Audio] P A T E N T D U C T U S A R T E R I O S U S Patent Ductus Arteriosus​ Blood leaving the aorta is shunted back to pulmonary artery traveling to LA Can cause Left Ventricular Volume Overload (LVVO) 5 / 1 2 / 2 0 2 6 3 9.

[Audio] E B S T E I N ' S A N O M A LY Ebsteins Anomaly Tricuspid leaflets are displaced apically one or more leaflets RV becomes smaller ARV- atrialized RV FRV-functional RV.

[Audio] " AT R I A L I Z E D " R I G H T V E N T R I C L E.

[Audio] T E T R A L O G Y O F FA L L O T Congenital heart defect A combination of 4 related heart defects that occur together: ①VSD ②Overriding aorta ③Pulmonary Stenosis ④Right ventricular hypertrophy.

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[Audio] ULTRASOUNDIMAGE: TETRALOGYOFFALLOT. U LT R A S O U N D I M A G E : T E T R A L O G Y O F F A L L O T.

[Audio] A B N O R M A L VA S C U L AT U R E Aortic Stenosis Pulmonic Stenosis Patent Foramen Ovale Left to right shunting Can cause Right-sided enlargement 5 / 1 2 / 2 0 2 6 4 5.

[Audio] VA S C U L A R A N O M A L I E S Endocardial Cushion Defect AKA: AV canal defect AV septal defect Partial or Complete Partial includes: Ostium primum ASD Cleft Mitral Valve Complete includes: ASD VSD Common AV Valve 5 / 1 2 / 2 0 2 6 4 6.

[Audio] A B N O R M A L VA S C U L AT U R E C O A R C T AT I O N O F A O R T A Narrowing of the aorta Near origin of left subclavian artery Result of shelf like tissue fold Preductal Postductal.

[Audio] A B N O R M A L V A S C U L A T U R : C O A R C T A T I O N O F A O R T A.

First une Across Coarctation Preductal Tubular hypoplasia At isthmus Interruption At isthmus Paraductal Between lett common carotid artery and duct Between lett common carotid and lett subclavian artery Postductal Between brachiocephalic artery and duct Between brachiocephalic and left common carotid artery Source: Expert Rev of Obstet Gynecol @ 2008 Expert Reviews Ltd.

[Audio] TRANSPOSITIONOF GREATARTERIES TheaortaoriginatesfromtheRVandthepulmonaryarteryoriginatesfromtheLVInTGA: Theconnectionsareswapped: TheaortacomesfromtheRV. ThepulmonaryarterycomesfromtheLV..