basic fetal echocardiography

FETAL ECHOCARDIOGRAPHY:Basics You Need To Know

JONAS D. DEL ROSARIO, MD, FPPS, FPCC

JDR2K

What is this?

JDR2K

Congenital Heart Disease

8 per 1000 live birth (3 in 1000 is critical)

True incidence is higher in the fetus (abortuses and stillborns) --- as high as 5x

Intrauterine cardiac malformations are associated with a high incidence of infant mortality and fetal wastage

Most common congenital malformation

JDR2K

Fetal Echocardiography

With the advent of ultrasound and the recent application of echocardiography to the human fetal heart, prenatal diagnosis and management of cardiac problems has become possible

JDR2K

Importance of ID of Heart Disease in Utero

Delivery at an appropriate facility

In utero therapy (arrhythmia, hydrops)

Reassurance for both mom and physician in the setting of an increased risk factor

Termination in some countries

JDR2K

Heart Defects Which Need INTERVENTION in the Perinatal Period

Arrrhythmia (SVT/Complete Heart Block)

Ductal-dependent lesions (HLHS, PA)

Myocardial dysfunction

EASILY DIAGNOSED WITH A DETAILED FETAL ECHO

JDR2K

When is the ideal time?

Fetal heart is most easily examined transabdominally at 18-24 weeks of gestation

Non-fixed fetal position

Incompletely calcified bones

Abundant amniotic fluid

JDR2K

20-week Fetal Heart

JDR2K

Indications for FETAL ECHO

Fetal Risks Familial Risks Maternal Risks

CHD Suspect (4C) CHD, parent CHD

Chromosomal Abn CHD, prior child Metabolic D/O

Extracardiac Defcts Mendelian Syn Teratogen Exp

Arrhythmia

Hydrops (Non-imm)

JDR2K

Technique

Transducer range 3-7 MHz

Segmental examination of the heart and great vessels

4 CHAMBER AND OUTFLOW TRACTS Views

Use of M-mode, 2 D, Pulsed and Color Flow Doppler

JDR2K

The accuracy is also very much dependent on the SONOGRAPHER’sknowledge and experience.

Understanding of the cardiac anatomy and physiology is mandatory.

JDR2K

Fetal Circulation

JDR2K

The American College of Obstetrics and Gynecology (ACOG) , 19884 chamber view of the fetal

hearton a prenatal screening ultrasound

JDR2K

Calculating Fetal Heart Size

JDR2K

Normal Cardiac Axis

left

spine

sternum

JDR2K

4-Chamber and ShortAxis of Ventricles

JDR2K

Normal Doppler:Aorta

JDR2K

Doppler Flow:Tricuspid Valve

JDR2K

Color Doppler: Aortic Arch

JDR2K

Color Doppler : Foramen Ovale

JDR2K

4-Chamber View

JDR2K

4 Chamber View

JDR2K

Pseudo VSD

JDR2K

Subcostal 4-Chamber View

JDR2K

4 Chamber View Alone

Sensitivity 43%-92% (Median 68%)

Studying the outflow tracts in some

prospective studies increased

sensitivity to as much as 25%

About 70% of CHDs have an

abnormal 4-chamber view

JDR2K

How accurate?

Various recent studies have reported sensitivity of 43-96% and a specificity approaching 100% with the variation depending on the sample population and technique employed, including interpretation.

JDR2K

Reasons for NON-detection(FALSE NEGATIVES)

Unique fetal circulatory pathways

(PFO,PDA)

Poor image quality of the fetus Early (<20 wks) or later (>34 wks)

Obesity

Low-quality machines

Milder obstructive lesions can develop late

Small defects

Unusual defects

Inexperienced echocardiographer, erroneous interpretation

JDR2K

CHDs with normal 4-Chamber View

TOF

DORV

Truncus Arteriosus

Outlet VSDs

D-TGA

Coarctation of the Aorta

JDR2K

The accuracy of detecting CHDs on a screening ultrasound improves with the addition of OUTFLOW tract evaluation.

JDR2K

Long-axis View of the Aorta

JDR2K

Short-axis View of the Great Vessels

JDR2K

Aortic Arch

JDR2K

What CHDs are usually and easily diagnosed?

Enlargement or hypoplasia of atrium or

ventricle

Atresia of tricuspid or mitral valve

Atresia of pulmonary valve or aortic valve

Large septal defects

Functional abnormalities

Abnormal heart rhythm

Abnormal contractility

JDR2K

Endocardial Fibroelastosis

JDR2K

Complete AVSD

JDR2K

Ebstein’s Anomaly

JDR2K

HLHS with Hydrops Fetalis

JDR2K

Truncus Arteriosus

JDR2K

CHDs not always diagnose prenatally

Small VSD

Mild pulmonary or aortic stenosis

Branch pulmonary artery stenosis

Anomalous pulmonary venous connection (especially partial)

Cardiac tumors (small)

Coarctation of the aorta (mild)

PDA and ASD

JDR2K

The cases of CHD detectable on FETAL ECHO constitute a more severecardiac anomaly with a less favorable long-term prognosis than the more minor defects infrequently detected.

JDR2K

Serial fetal echo examinations improve accuracy and gives us a good picture of disease progression especially in high-risk conditions.

JDR2K

Functional Abnormalities

Chamber sizes, wall thickness

Contractility (Ejection Fraction,Fractional Shortening)

AV Valve Regurgitation

RHYTHM

ESPECIALLY IN THE SETTING OFHYDROPS FETALIS

JDR2K

HLHS with Hydrops Fetalis

JDR2K

M-mode Measurements

JDR2K

M-Mode Tracing

JDR2K

Hypertrophic Cardiomyopathy

JDR2K

Fetal Arrhythmias

Aside from detection of

structural heart disease, FETAL

ECHO has also enabled

pediatric cardiologists to assess and treat fetal

arrhythmias.

JDR2K

Sinus Rhythym

JDR2K

Normal Sinus Rhythm: Doppler Method

JDR2K

Fetal Arrhythmias

1% of fetuses

Indications for evaluation

Sustained FHR of < 100 BPM

Sustained FHR of > 180 BPM

Repetitive Irregular Heartbeats

Unexplained Hydrops Fetalis

JDR2K

Fetal Arrhythmias

ISOLATED ATRIAL EXTRASYSTOLES(PACs) is the most common

Self limited

Resolves spontaneously

Carries a benign prognosis though itmay persist for a variable period

JDR2K

Premature Atrial Contractions

JDR2K

Fetal Arrhythmias

Sustained tachyarrhythmias can lead to intrauterine cardiac failure, hydrops fetalis and fetal demise.

JDR2K

Significant Fetal ArrhythmiasMost Common

SUPRAVENTRICULAR TACHYCARDIA (SVT)

ATRIAL FLUTTER

COMPLETE HEART BLOCK

JDR2K

Fetal SVT

Most common

When sustained for 24 hours ---HYDROPS FETALIS

DIGOXIN is still drug of choice

Procainamide, Quinidine,Verapamil, Sotalol and Amiodarone

JDR2K

Supraventricular Tachycardia

JDR2K

Fetal Atrial Flutter

Difficult to treat

Digoxin remains drug of choice

Guarded prognosis in about 20%

JDR2K

Atrial Flutter

JDR2K

Fetal Complete Heart Block

Associated with structural heart disease in 50-60%

Outcome is poor if associated CHD, reported 80% perinatal mortality

In normal hearts, association with Maternal Connective Tissue D (SLE), screening of mom warranted (SS-A and SS-B antibodies)

JDR2K

Complete Heart Block

JDR2K

Complete Heart Block

JDR2K

Summary

Fetal cardiology has made great strides in the detection of fetal heart disease thru FETAL ECHOCARDIOGRAPHY

Fetal ECHO is a relatively risk- free procedure and in the hands of an experienced fetal cardiologist has a high degree of sensitivity and specificity

JDR2K

Summary

Fetal Echo enables us to diagnose

structural and functional heart disease

in-utero as early as 16 wks of AOG

4-chamber and outflow tract views are

important to diagnose more than 90% of

heart disease

Some CHDs are difficult to diagnose in-

utero (but are not critical)

JDR2K

Summary

Most common indications for evaluation are suspected CHD on level 1 ultrasound, chromosomal abnormalities, extracardiac anomalies, family history of CHD, maternal diabetes and maternal teratogen exposure

Prenatal diagnosis of CHD may alter the natural course of CHD and improve on the perinatal morbidity and mortality

JDR2K

THANK YOU