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
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Heart and SoulEvaluation 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 Associated Anomaly
Primitive heart tube Lethal defects
LoopingDextrocardia, Situs inversus totalis, Heterotaxy,
Corrected TGA
Wedging/ventricular development
VSDs, hypoplastic ventricles, Double outlet right ventricle, double inlet left ventricle
Atrial septation Common atrium, atrial septal defects
Systemic and pulmonary veins
Bilateral SVCs, Interrupted IVC/azygous vein, Total anomalous pulmonary return
Atrioventricular valves Epstein's, atresia of the AV valve
Aortic and Pulmonary outflow tracts
Truncus arteriosus, double outlet RV, double inlet LV, TGA, absent DA, DiGeorge syndrome, CATCH 22
Aortic archCatch 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 cavalconnections 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
mPAaAO
lPA 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
Ventricular Septal Defect
Ventricular Septal Defect
Ventricular Septal Defect
Atrioventricular Septal Defect
The AVSD
Ebstein’s Anomaly
Ebstein’s Anomaly
Tricuspid Regurgitation
Hypoplastic Left Heart
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
Case 2
Case 2
The Cardiac Mass
The Cardiac Mass
The Cardiac Mass
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
PACs
PACs
Supraventricular Tachycardia
SVT
Pericardial Effusion
The “Sail”Sign
Mechanical PR Interval
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 Left superior vena cava, azygous vein
PA and AO Not Continuous Interupted aortic arch
Vessel to Right of Trachea Right sided aortic arch
Ao Anterior to PA Transposition of the great vessels
Small PA – anterograde Flow Tetralogy of Fallot
Small PA – Retrograde Flow Pulmonary Atresia
Small Ao Hypoplastic left heart
Summary Planes
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