Heart and Soul Evaluation of the Fetal Heart

Heart and Soul Evaluation of the Fetal Heart Ivana M. Vettraino, M.D., M.B.A. Clinical Associate Professor, Michigan State University College of Human Medicine

Objectives Review the embryology of the formation of the heart Compare and contrast fetal versus post-natal circulation List indications for detailed assessment of the fetal heart Review abnormal fetal cardiac anatomy. Discuss the role of the 3 vessel and 3 vessel trachea view

Introduction Congenital anomalies are the leading cause of infant death Congenital heart disease (CHD) accounts for 30 to 50 percent of these deaths CHD is the most common congenital disorder in newborns Affect 40,000 infants born in the USA each year Prevalence 6 to 13 per 1000 live births 8 per 1000 live births the average quoted

Introduction March of Dimes Data

Introduction Critical CHD is present in approximately 25 to 50 percent Most are ductal dependent lesions Coarctation of the aorta, interrupted aortic arch, aortic stenosis, pulmonary stenosis, hypoplastic left heart syndrome, transpositions of the great vessels, tetralogy of Fallot Non ductal dependent lesions Total anomalous pulmonary return, truncus arteriosus Risk of morbidity and mortality increases in this group with delayed diagnosis A missed diagnosis is thought to occur in approximatley 1 in 15,000 births

EMBRYOLOGY OF THE HEART

Congenital Heart Disease Stage of Development Primitive heart tube Looping Wedging/ventricular development Atrial septation Systemic and pulmonary veins Atrioventricular valves Aortic and Pulmonary outflow tracts Aortic arch Associated Anomaly Lethal defects Dextrocardia, Situs inversus totalis, Heterotaxy, Corrected TGA VSDs, hypoplastic ventricles, Double outlet right ventricle, double inlet left ventricle Common atrium, atrial septal defects Bilateral SVCs, Interrupted IVC/azygous vein, Total anomalous pulmonary return Epstein's, atresia of the AV valve Truncus arteriosus, double outlet RV, double inlet LV, TGA, absent DA, DiGeorge syndrome, CATCH 22 Catch 22, interrupted aortic arch, right aortic arch, tetralogy of Fallot, aberrant subclavian veins

FETAL AND NEONATAL CIRCULATION

The fetal circulation. Fetal Circulation

Summary

THE FETAL HEART EXAM

2007

2013

General Considerations

Changes Since 2007 Color Doppler sonography was optional now required M-Mode optional now required Pulsed Doppler required AV valves Semilunar valves Ductus venosus Cardiac rhythm disturbance

Essentially Unchanged Since 2007 Cardiac Biometry Optional But Should Be Considered for Suspected Structural or Functional Anomalies Cardiac Function Assessment Optional But Should Be Considered for Suspected Structural or Functional Cardiac Anomalies Complementary Imaging Strategies Optional 3- and 4-dimensional sonography

Indications for Fetal Echocardiogram Maternal Indications Autoimmune antibodies anti-ro (SSA)/anti-La (SSB) Familial inherited disorders 22q11.2 deletion In vitro fertilization Metabolic disease Diabetes mellitus Teratogen exposure Lithium Fetal Indications Abnormal cardiac screen First-degree relative of fetus with congenital heart disease Abnormal heart rate or rhythm Fetal chromosomal anomaly Extracardiac anomaly Hydrops Increased nuchal translucency/fold Monochorionic twins

The Basics Determine situs Do not assume that the situs is correct if the stomach and heart are on the same side Evaluate size Fetal heart occupies one third of the area of the fetal chest with an axis ~ 45 degrees to the left Cardiac circumference to chest circumference greater than 0.5 consistent with an enlarged heart

The Basics Visualization of fetal heart possible in the first trimester Optimal time to perform cardiac screening is between 18 and 22 weeks gestation Apical four-chamber is main screening view Evaluation of situs Evaluation of size Position Anatomy Function

Situs

The Basics The position Levocardia Heart located in left chest with apex pointing to the left Dextrocardia Heart located in right chest with apex pointing to the right Mesocardia Heart centrally located with apex pointing anteriorly Abnormalities of position can be associated with other cardiac anomalies

Cardiac Axis Obstet Gynecol 1987;70:255.

Cardiac Size

The Apical Four Chamber View

The Basics Four-chamber view Detect 43% to 96% of fetuses with CHD As a screening tool in general population expected to detect 40% to 50% of cases of CHD Ability to image the fetal heart influenced by gestational age, fetal position, amniotic fluid volume, and maternal body habitus

Structures Seen in the 4 Chamber View Atrial and ventricular size Atrial and ventricular septae Atrioventricular size and function Coronary sinus Ventricular function in long axis Semilunar valve function Pulmonary veins

Four Chamber Screening View Abnormalities easily missed on four chamber Ventricular septal defects Atrial septal defects Coarctation Tetralogy of Fallot Transposition of the great arteries Double-outlet right ventricle Truncus arteriosus Total anomalous pulmonary venous return

The Outflow Tracts Increases detection rate of CHD to 70 to 90% Cardiac anomalies associated with outflow tracts detected in only 6.7 percent of cases Left ventricular outflow tract (LVOT) 45 tilt of transducer from the four chamber view perpendicular to the septum to an oblique view from the fetal left upper quadrant of the abdomen to the right fetal shoulder Right ventricular outflow tract (RVOT) Further rotation in the same direction as noted above and rocking the transducer from the LVOT

Four Chamber and Outflows

Scanning Planes

Fetal Cardiac Scanning Short-axis view Obtained by scanning perpendicular to long axis of the heart Long-axis view Aligned with the left ventricular outflow tract Caval long-axis view Obtained with the imaging plane parallel to the caval connections to the right atrium Ductal view Obtained when the imaging plane is aligned with the right ventricular outflow tract and main pulmonary artery Aortic arch Obtained with the beam aligned from anterior right of fetal chest to posterior left of fetal chest

The Outflow Tracts Left Ventricular Outflow Tract (LVOT)

The Outflow Tracts Right Ventricular Outflow Tract (RVOT)

The Outflow Tracts

EXAMPLES

The Apical Four Chamber View

The Short Axis View RV mpa lpa aao rpa SVC

The Aortic Arch

Aortic Arch and Inferior Vena Cava

The Vena Cavas

The Ductal Arch

Three Vessel View

Four Chamber View

Ventricular Septal Defect

Atrioventricular Septal Defect

The AVSD

Ebstein s Anomaly

Tricuspid Regurgitation

Hypoplastic Left Heart

HLHS

Transposition of the Great Vessels (TGA)

TGA Three Vessel View

Tetralogy of Fallot Large ventricular septal defect Over-riding aorta Pulmonary stenosis Right ventricular hypertrophy

Case

Case Liver Bowel

Pentalogy of Cantrell Rare form of abdominal wall defect Five Associated Anomalies Midline epigastric abdominal wall defect Defect of the lower sternum Deficiency of the anterior diaphragm Defect in the diaphragmatic pericardium Intra cardiac defects

Case 2

The Cardiac Mass

FETAL CARDIAC DYSRHYTHMIAS

Cardiac Dysrhythmia Occur in 1 to 3 percent of all pregnancies Detected by auscultation Most are benign Most are ectopic premature atrial contractions 10% of pregnancies complicated by fetal arrhythmias, have a potentially life threatening arrhythmia Tachyarrhythmias (heart rate in excess of 180 beats/min) Supraventricular tachycardia (SVT) Atrial flutter (AFL) Bradyarrhythmias (heart rate less than 100 beats/min) Second-degree atrioventricular (AV) block Complete AV block (CAVB)

Premature Atrial Contraction

PACs

Supraventricular Tachycardia

SVT

Pericardial Effusion

The Sail Sign

Mechanical PR Interval

THE FUTURE

The Three Vessel View http://www.ultrasoundpaedia.com/normal-fetal-heart2/

The Three Vessel View

The Three Vessel Trachea View

The Three Vessel Trachea View http://obgynkey.com/the-three-vessel-trachea-view-and-upper-mediastinum/

The Three Vessel Trachea View The Normal View Three vessels All vessels to the left of the trachea Vessels similar in size Pulmonary artery (PA) anterior of the Aorta (Ao) Continuous PA and Ao Flow toward the spine in PA and Ao

The Three Vessel View Blood flow toward the spine in PA and Ao

The Three Vessel Trachea View Examples of abnormalities Too Many Vessels PA and AO Not Continuous Vessel to Right of Trachea Ao Anterior to PA Small PA anterograde Flow Small PA Retrograde Flow Small Ao Left superior vena cava, azygous vein Interupted aortic arch Right sided aortic arch Transposition of the great vessels Tetralogy of Fallot Pulmonary Atresia Hypoplastic left heart

Summary Planes