Fetal Echocardiography

1. Fetal Echocardiography Renee A. Bornemeier, M.D. Associate Professor Division of Pediatric Cardiology University of Arkansas for Medical Sciences Medical Director, ACH Heart Station Arkansas Children’s Hospital

2. Overview • Cardiac Embryology • Fetal & Neonatal Physiology • Indications for Fetal Echocardiography • Timing of the Examination • Examination Technique • Normal Fetal Cardiac Exam • Abnormal Exams

3. Cardiac Embryology • Heart begins to beat in the embryo @ day 21 post conception • Begins as a straight tube • Grows faster than any other organ in the chest and therefore loops • Over the next 3-4 weeks, the atria,ventricles,and truncus arteriosus septate

4. Cardiac Embryology • The primitive double aortic arch differentiates into the typical left 4th arch and the left 6th arch is maintained as the ductus • The pulmonary veins coalesce and connect to the heart via the common pulmonary vein.

5. Cardiac Embryology • So by the time the embryo is 7-8 weeks old the heart is fully septated and the intracardiac structure determined.

6. Fetal Circulation • Oxygenated blood from the mother enters the fetus through the umbilical vein. • Umbilical vein drains into the IVC and into the Right Atrium. • The majority of this blood then travels across the Foramen Ovale into the Left Atrium Left Ventricle Ascending Aorta to head, neck, arms and some to the body.

7. Fetal Circulation • Blood from the SVC returns to the Right Atrium and primarily crosses the tricuspid valve, enters the Right Ventricle, and is pumped out to the Pulmonary Artery. • Pulmonary Vascular Resistance is quite high in the fetus and very little blood flow enters the branch PAs and traverses the lung.

8. Fetal Circulation • The majority of blood entering the Pulmonary Artery is shunted through the ductus arteriosus and down the Descending Aorta to the lower body, umbilical artery, and low resistance placental bed.

9. At Birth • As a baby begins to breathe on its own Pulmonary vascular resistance falls. The oxygen content of the blood rises. • The umbilical cord is clamped and the low resistance placental bed is gone - and Systemic Vascular Resistance rises. • Ductus Arteriosus begins to close, and shunting through the Foramen Ovale decreases and may even change direction.

10. Normal Fetal Heart • Evaluate Heart Rate and Function. • Evaluate the Abdominal and Atrial Situs. • Evaluate the Atrial-Ventricular Connections. • Evaluate the Ventricular-Arterial Alignment. • Evaluate the Great Arteries relationship to each other.

11. Normal Fetal Heart • Determine position fetus • Begin in an axial plane - 4 chamber view • heart occupies@1/3 of fetal chest • Assess abdominal & thoracic situs. • Liver on the right, stomach on the left, apex of the heart pointed to the left. • 4 chambers should be seen.

12. Normal Fetal Heart • SVC & IVC return to the RA • Foramen Ovale should drain blood from RA to the LA. • May be able to see pulmonary veins entering the LA - but may not because of fetal physiology • The Atria should be of equal size • R & L Ventricle of equal size • 2 AV valves should be seen.

13. Normal Fetal Heart • Ventricular septum should appear intact • The lower atrial septum should fuse with the AV valves/ventricular septum. • The LV should be posterior and the RV should be anterior. • The Aorta should arise from the LV and be located slightly posterior to the PA and head rightward.

14. Normal Fetal Heart • The PA should arise from the RV and be anterior to the Aorta and head leftward. • The Pulmonary Artery should CROSSOVER the Aorta. • The Aorta & Pulmonary Artery should be roughly the same size.

15. Normal Fetal Heart • The Ductus Arteriosus connects the Pulmonary Artery to the Descending Aorta. • Saggital View - to look at the Aortic and Ductal Arch. • Aortic arch should be a tighter curve than the Ductal arch and the Aorta should have head vessels. • Flow in the aorta and duct should be the same direction

16. Normal Fetal Heart • Ductal Arch should be longer, less curved-flatter, & no head vessels. • Frontal View • SVC and IVC/Hepatic veins should be identified draining into the Right Atrium. • Short Axis • Assess function and septum

17. Fetal Arrhythmias • Should be one Atrial contraction for each Ventricular contraction. • Premature Atrial Contractions - most often benign, go away after birth. • Premature Ventricular Contractions-more rare.

18. Fetal Arrhythmias • Transient Bradycardia • Complete Congenital Heart Block - Check mom for autoimmune disorder • Supraventricular Tachycardia - HR usually 250-300 bpm • May have to medicate the mother to try and get arrhythmia under control. • Ventricular Tachycardia - very rare

19. Fetal Arrhythmias • To evaluate arrhythmias obtain a M-mode through the atria wall and the aortic valve or ventricular wall. • You may also assess this by doppler analysis of the inflow and outflow patterns

20. Carbamazepine Cocaine Coumadin Cyclophosphamide Daunorubicin Dextroamphetamine Diazepam Ethanol ASD,PDA ASD,VSD,TGA,CCHB CHD TOF TOF CHD CHD ASD,VSD,DORV,TOF,PDA,PA,Dextro Drugs with Teratogenic Effects

21. Lithium Methotrexate Phenytoin Primidone Retinoic Acid Thalidomide Thimethadione Valproic Acid Vitamin D ?Ebstein’s Anomaly Dextro,TOF CHD ?VSD CHD CHD ASD,VSD,PDA TOF,PDA,AS,VSD PS,Supra AS Drugs with Teratogenic Effects

22. Trisomy 21 Trisomy 18 Trisomy 13 Turner’s Syndrome Noonan’s Syndrome Vacteral Association Charge Association Ellis-Van-Crevald Cornelia DeLange Goldenhar DiGeorge Syndrome Velo-cardo-facial Holt-Oram Tuberous Sclerosis Williams Marfan/Ehler-Danlos Syndromes most commonly associated with CHD

23. Maternal Factors Predisposing to CHD • Diabetes Mellitus • AutoImmune Disease - SLE • Maternal Infection - CMV,Rubella,Coxsackie • Phenylketonuria • Maternal (Parental) CHD • Drug Exposure

24. Fetal Factors Predisposing to CHD • Abnormal Karyotype • Midline Defects • Hydrops Fetalis • Oligohydramnios/Polyhydramnios • 2-vessel cord • Fetal Arrhythmia • Suspected CHD on routine scan

25. Familial Factors Predisposing to CHD • HX of CHD - left heart obstruction • Genetic Syndromes • HCM • Holt-Oram • Noonan’s Syndrome • Marfan • Tuberous Sclerosis

26. Timing of the Fetal Echo • Optimal time for scan is between 20-25 weeks gestation. • Heart large enough to see detail • Ribs not as dense • Varied positions • Scanning Earlier - still room for error • Scanning Later - Fetal positions are more limited & increased rib density

27. Factors influencing the Quality of the Fetal Echocardiogram • Maternal Obesity • Polyhydramnios • Oligohydramnios • Previous Abdominal Surgery • Fetal Position

28. 2-D Fetal Cardiac Exam A normal fetal heart is Symmetric

29. 2-D Screening Fetal Cardiac Exam • Find the four chamber view • R & L atria and R & L ventricle should appear fairly equal in size • Floppy foramen ovale tissue – bowing RA to LA • RV can be identified by the moderator band and should be anterior to the LV

30. 2-D Screening Fetal Cardiac Exam • Look for obvious septal defects • Aorta should arise from the LV • The PA should arise anterior and cranial to the aorta and actually cross over the aortic outflow • Great arteries should fairly equal in size (PA>Ao)

31. Fetal Echocardiogram • Determine the : • Systemic Venous Return • Atrio-Ventricular connections • Ventriculo-Arterial alignment • Aortic and Ductal Arch • Branch PAs • attempt to see PVs • Look at valve function • Look at the overall cardiac function

32. Fetal Chest - 4 Chamber View

33. Fetal Cardiac 4 Chamber View

34. Fetal Cardiac 5 Chamber View

35. Great Vessel View

36. Limitations of Fetal Echo • Small VSDs • Minor valve abnormalities • Coronary Anomalies • Coarctation of the Aorta • TAPVR • 20ASDs & other rare forms • PDA

37. The Normal Fetal Heart