Fetal Echocardiography Dr. Durr-e-Sabih Una contribucion para Dr Lattus de Dr. Hector Fernandez

Why Commoner than most realize 1% in all live births Approximately 5% in all pregnancies The incidence increases if there is a positive family history if sibling affected incidence is 2 – 4% if mother affected incidence is 10-12%

Indications Family history Exposure to known cardiac teratogens Chromosomal abnormalities (trisomy 21, 50%; trisomy 13 and 18, almost 100%) Maternal disease (diabetes, collagen disease, phenylketonuria, infections) Non-cardiac abnormalities detected on US Polyhydramnios

WeeksLength mm Event` No heart or great vessel 42Single median cardiac tube, ineffective contraction 54Bilobed atrium 54Begining of circulation 57.5AV orifices, 3 chamber heart Septum secundum, complete inferior septum, divided truncus arteriosus, 7204 chamber heart Cardiac embryology

Cardiac Size 20 week fetus’ heart compared with an American quarter Usual HR /min

Time The best time to do a fetal cardiac exam is weeks Later exams may show anatomy better but might be difficult because of rib shadowing Adequate exam depends on fetal position and maternal habitus Some pathologies become obvious with fetal age

Fetal Circulation Fetal circulation is complex and different from adult blood flows with three major shunts: Ductus venosus Forman ovale Ductus arterosus

Rate and rhythm The heart rate is usually /min, the rhythm is regular but transient bradycardia is normal in the 2 nd trimester but not in the 3rd

First assess fetal position

Acquire a four chamber view Transverse section through the fetal thorax Corresponds to the 4 chamber apical view in the adult The atrium nearest the spine is the left atrium The atrium nearest the fetal anterior thoracic wall is the right

Axis o towards the left Abnormal axis increases the risk of a cardiac malformation The heart may also be displaced from its normal position in dipaphragmatic hernia or cystic adenomatoid malformation

Fetus cephalic Probe marker to mother’s left Fetal spine posterior

Fetus breech Probe marker normal Fetal spine posterior

Basic fetal cardiac examination Done on a 4 chamber view Heart mostly in left chest Occupies 1/3 rd of thoracic area Normal cardiac situs, axis and position No pericardial effusion General

Basic fetal cardiac examination Both of same size Foramen ovale flap in left atrium lower end of atrial septum (septum primum) present Atria

Lower end of septum Foramen ovale Flap of foramen ovale in LA

Basic fetal cardiac examination Equal size Intact septum Moderator band identifies right ventricle Ventricles

Both of same size Moderator band identifies right ventricle

Basic fetal cardiac examination Both valves move freely Tricuspid valve inserted more apically than mitral AV Valves

Extended basic cardiac examination The outflow tracts are imaged by tilting the probe towards the fetal head The great vessels should be of equal size and should cross at approximately 90 o as they emerge from their respective ventricles

Look for these: The outflow tracts cross each other at about 90 o The anterior aortic root wall is continuous with the Inter Ventricular Septum The pulmonary artery bifurcates The aortic and pulmonary valves move freely Both great vessels are of similar size but the pulmonary artery tends to be slightly bigger

The aortic arch The aortic arch can be identified The aortic cusps can be seen

The pulmonary artery bifurcates

The outflow tracts cross at around 90 o Pulm trunk Aortic arch

Cases

Echogenic Intracardiac Focus (EIF) Can be seen in up to 6% of normal pregnancies Highly operator and machine dependant Associated with cardiac and extracardiac anomalies Bilateral EIF is more significant

EIF Biventricular EIF are more significant this patient was 47XY Normal nuchal translucency