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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