FETAL ECHO&

FETAL THERAPIES

DR SANDEEP.RSR CARDIO

INTRODUCTION

• Congenital heart disease a leading cause of infant mortality – 4-13 /1000 live births

• Account for about 50% of all neonatal and infant deaths

• Prenatal detection can improve pregnancy outcomes

• CHD is more common in low risk pregnancies

• Screening tools like nuchal fold thickness ,ductal venosus doppler less sensitive

FETAL ECHO•Fetal echocardiography is broadly defined as a detailed

sonographic evaluation that is used to identify and

characterize fetal heart anomalies before delivery

• Provides information regarding:

Fetal cardiac anatomy & function

Fetal heart rhythm

Fetal heart failure & distress

The Role of Fetal Echocardiography in Fetal Intervention:A Symbiotic Relationship Clin Perinatol 36 (2009) 301–327

UNIQUE FEATURES OF FETAL CIRCULATION

• Presence of intracardiac & vascular passages

that allow for streaming of blood( DA,DV&

foramen ovale)

Many critical CHD’s are well tolerated

in utero ( except regurgitant lesions)

• Cardiac output is exclusively dependent on a

narrow range of heart rate

Arrhythmia’s are very poorly tolerated

ADVANTAGES OF FETAL ECHO – Improvement of fetal outcomes of infants with severe cardiac malformations

– Helps in more specific family counselling

– Timely referral of mothers with affected fetuses to tertiary cardiac care centers for

neonatal management

– Early diagnosis of CHD allows prompt evaluation of genetic syndromes and analysis of

the fetal karyotype.

– Prenatal detection of arrhythmias allows for in utero treatment

– Identifies patients for in utero cardiac interventions that may be performed at certain

select centers

ASE GUIDELINES FOR FETAL ECHO Journal of the American Society of Echocardiography Volume 17 Number 7 2004

EQUIPMENT

• High Frames rates required

• All modalities of Doppler including color,

pulse, high PRF , CW required

• Tissue Doppler imaging used in the

assessment of fetal arrhythmia

• High frequency probes for resolution & detail

• Curvilinear probes more patient friendly

• Real time assesment required than still images

ASE GUIDELINES FOR FETAL ECHO Journal of the American Society of Echocardiography Volume 17 Number 7 2004

CURVILINEAR PROBE

WHO SHOULD PERFORM FETAL ECHO?

• Physician should be

– Well versed in various modalities eg.M-mode,2D, color Doppler

– Able to identify simple & complex CHD

– Should have knowledge of natural H/O of CHD in pregnancy

– Should know limitations of fetal echo

– Should have understanding of fetal arrhythmias

– Aware of latest dvpnt in fetal therapy

– Should have an understanding of maternal fetal physiology

• Appropriately trained obstetricians, maternal-fetal medicine specialists, pediatric

cardiologists & radiologists with special expertise in fetal imagingASE GUIDELINES FOR FETAL ECHO Journal of the American Society of Echocardiography Volume 17 Number 7 2004

TIMING OF FETAL ECHO

• Fetal echo possible by transvaginal approach by 9-10 weeks of gestation

• In the first trimester (11-14 weeks), cardiac details may not be elicited well,

but the presence of a pulsatile ductus venosus or tricuspid regurgitation - a

very strong marker for cardiac and chromosomal anomalies.

• Optimal timing - 18 - 22 weeks gestational age

• Image acquisition difficult after 30 weeks

– Fetal rib shadowing,

– Fetal position

– Maternal body habitus

ANITA SAXENA ET al FETAL ECHO WERE ARE WE? INDIAN JOURNAL OF PEDIATRICS July 2005

INDICATIONS OF FETAL ECHOMATERNAL INDICATIONS FETAL INDICATIONS

•Family history of CHD

•Metabolic disorders (eg,diabetes, PKU)

•Exposure to teratogens

•Exposure to prostaglandin synthetase inhibitors (eg, ibuprofen, salicylic acid)

•Rubella infection

•Autoimmune disease (eg,SLE, Sjogren’s)

•Familial inherited disorders(Ellisvan Creveld, Marfan,Noonan’s, etc)

•In vitro fertilization

• Abnormal cardiac screening examination• Abnormal heart rate or rhythm• Fetal chromosomal anomaly• Extracardiac anomaly( Git/spina bifida)

• Non immune hydrops• Increased nuchal translucency >3.5mm• Monochorionic twins• Unexplained severe polyhydramnios

ASE GUIDELINES FOR FETAL ECHO Journal of the American Society of Echocardiography Volume 17 Number 7 2004

RECURRENCE RISK OF CHD

• Cardiac anomalies are known to cluster in families; the risk of having a

child with a cardiac anomaly is as follows:

– If a previous child was born with a CHD, the probability of a subsequent child

being born with a CHD is 1:20 to 1:100

– If two previous children were born with CHD, the risk is 1:10 to 1:20

– If the mother has CHD, the risk is as high as 1:5 to 1:20

– If the father has CHD, the risk is 1:30

Indian journal of radiology imaging,Feb 2009,Vol19, issue 1

LIMITATIONS• Operator dependent

• Technical limitations

– Poor fetal positioning

– Difficult imaging due to maternal body habitus.

– Multiple fetuses may create a shadowing phenomenon

• Difficult to diagnose

– Small VSD

– Difficult to differentiate OS ASD vs flow through the foramen ovale

– Anomalies of pulmonary veins

– PDA

Pediatr Clin N Am 56 (2009) 709–715

FIRST TRIMESTER MARKERS OF CHD(11-14 WKS)

• Nuchal fold thickness > 3.5mm is associated with increased incidence of chromosomal anomalies & CHD

• The presence of tricuspid regurgitation (TR) determined by pulsed wave Doppler has been shown to be a marker for trisomy 21 & CHD

• Abnormal flow( absenceof a wave or reversal of a wave ) in the Ductus venosus doppler associated with an increased risk of chromosomal abnormalities and CHD

FIRST TRIMESTER FETAL ECHOCARDIOGRAPHY. STATE OF THE PROBLEM TMJ 2009, Vol. 59, No. 2

FETAL POSITION

J AM SOC ECHOCARDIOGRAPHY 1994;7:47-53

POSITION OF SPINE IS FIXED

• Transducer aligned in a sagittal plane

• Index marker toward maternal head

• Fetal lie is established (cephalic/breech, etc.)

• Transducer is rotated 90° counter-clockwise

• Left/right fetal orientation is established

TRANSVERSE ABDOMINAL VIEW

J AM SOC ECHOCARDIOGRAPHY 1994;7:47-53

SITUS

•Transverse view of abdomen

•Stomach lies on the left

•Aorta anterior and left of spine

•IVC anterior and to right of aorta

•IVC & aorta of same size

4-CHAMBER VIEW

POSITION OF THE HEARTCardiac position

• Levocardia (normal)

• Mesocardia

• Dextrocardia

Cardiac malposition

• High incidence of CHD association

• Heterotaxy Syndrome (“bilateral sidedness”)

• May be caused by space-occupying lesions

• Congenital Cystic Adenomatoid Malformation (CCAM)

• Congenital Diaphragmatic Hernia (CDH)

• Congenital Lobar Emphysema

• Pulmonary Sequestrations

• Lung hypoplasia/agenesis

4- CHAMBER VIEW - AXIS OF THE HEART

• NORMAL AXIS - 45 ± 20 degrees towards the left side of fetus

•Abnormal axis increases the risk of a cardiac malformation involving the outflow tracts

• Maybe associated with chromosomal anomalies

• Abnormal cardiac position can be caused by a diaphragmatic hernia or space-occupying

lesion, such as cystic adenomatoid malformation or fetal lung hypoplasia or agenesis

4-C VIEW

Cardiac screening examination of the fetus: guidelines for performing the ‘basic’ and ‘extended basic’ cardiac scan

4-C VIEW

• CARDIAC SIZE

• CARDIAC/THORACIC RATIO

• Normally ≤ .3

TILT FOR OUTFLOW VIEWS

LVOT VIEW

LVOT VIEW• Confirms the presence of a great

vessel originating from the LV

• Continuity seen between the anterior aortic wall and ventricular septum

• Great vessel is aorta if it can be traced into its arch & with orgin of three arteries into the neck

• Freely moving aortic valve which is not thickened

• Able to identify VSD and conotruncal abnormalities

RVOT VIEW

• Documents the presence of a great

vessel from a morphologic RV with a

moderator band

• The PA normally arises from the RV

and courses toward the left of the

more posterior ascending aorta.

• It is usually slightly larger than the

aortic root during fetal life and

crosses the ascending aorta at about

a 700 angle just above its origin

RVOT VIEWThe pulmonary arterial valves move freely and should not be thickened

The RVOT can be confirmed as a pulmonary artery only if its distal end appears bifurcated

The distal pulmonary artery normally dividestoward the left side into a ductus arteriosus that continues into the descending aorta

The right side branches into the right pulmonary artery

3 VESSEL VIEW

The left and right ventricular outflow tracts are directed almost at right angles to each other at their origin

3 VESSEL TRACHEAL VIEW

The main features to confirm from this view are that:

1. The vessels from fetal left to right are the PA, AO & SVC with the PA being the more anterior vessel.

2. The aortic arch and pulmonary artery/ductal arch should be approximately equal in width at about

20 weeks At later gestations, the pulmonary artery tends to be a little bigger than the aorta.

A marked discrepancy in size (aorta smaller than pulmonary artery) may indicate the presence of

coarctation of the aorta

AIUM Practice Guideline for the Performance of Fetal Echocardiography J Ultrasound Med 2013; 32: 1067–1082

SHORT AXIS VIEW

•Ventricular minor dimensions

•Ventricular septal integrity

•Papillary muscle arrangement

•Ventricular function

LONG AXIS VIEWS

• Sagittal view of ductal arch not

visualized in pt. With conotruncal

anomalies

• Helps in prenatal diagnosis of

conotruncal anomalies

• Enables in diagnosis of coarctation

DOPPLER

• Spectral, CW , color, PW Doppler

sonography can be used to evaluate the

following structures for potential flow or

rhythm abn.

• Pulmonary veins

• Foramen ovale

• Atrioventricular valves

• Atrial and ventricular septa

• Aortic and pulmonary valves

• Ductus arteriosus

• Aortic arch

RT TO LT FLOWTHROUGH PFO

DOPPLERUMBLICAL VESSELS

PULMONARY VEIN DOPPLER

VENTRICULAR INFLOW

LVOT FLOW

RVOT FLOW

SPECTRAL DOPPLER IN ARRHYTHMIA

CHB

ATRIAL FLUTTER

2:1 AV BLOCK

SINUS TACHYCARDIA

M-MODE•M-Mode Echocardiography (Optional) recommended for cardiac rate or rhythm abnormalities

•Normal fetal heart rate 120-160 BPM

•Heart rate > 160 beats/ Mt – tachycardia

•Fetal heart rate < 100/mt - bradycardia

•Spectral Doppler or m-mode assessment

•Confirm 1:1 conduction

CHB

CARDIAC ARRYTHMIAS

SVT

SVT WITH SHORT VA INTERVAL

SVT WITH LONG VA INTERVAL

FETAL ECHO ABNORMALITIES VSD

ENOCARDIAL CUSHION DEFECT

AORTIC STENOSIS

COARCTATION OF AORTA

FETAL ECHO ABNORMALITIES

• TRUNCUS ARTERIOSUSTOF

FETAL THERAPIES• Fetal treatment (or fetal therapy) is the

“operative branch” of fetal medicine

• It includes a series of interventions

performed on the “sick” fetus with the aim

of achieving fetal well being

• These interventions include medical (i.e.

non-invasive) and surgical procedures.

Doff B. McElhinney, Wayne Tworetzky and James E. Lock Current Status of Fetal Cardiac Intervention2010;121:1256-1263 Circulation

FETAL INTERVENTIONS

CLASSIFICATION

• FETAL CARDIAC INTERVENTION(FCI)

Doff B. McElhinney, Wayne Tworetzky and James E. Lock Current Status of Fetal Cardiac Intervention2010;121:1256-1263 Circulation.

PHARMACOLOGICALFCI INVASIVE FCI

CLOSED FCIOPEN FCI

PHARMACOLOGICAL FCI

FETAL TACHYARRYTHMIAS –VT/SVT/ATRIAL FLUTTERFetal SVT – AVRT / atrial flutter most common indication for pharmacological cardiac

intervention Digoxin has been a mainstay of therapyother agents used are

SotalolAmiodarone FlecainidePropranolol

Modes of administeration1) Intravenous2) Transplacental3) Umblical vein4) Maternal oral administeration

INDICATION FOR THERAPY

1.FETAL HYDROPS2. SUSTAINED TACHYCARDIA3.CARDIAC DYSFUNCTION

PHARMACOLOGICAL FCI

• FETAL BRADYCARDIA• Sustained fetal bradycardia may be caused by sinus node dysfunction, long-QT syndrome,

AV block, or fetal distress with acidosis

• The most common fetal bradyarrhythmia and the primary indication for FCI is high-grade AV block with ventricular rate < 55/mt

• AV BLOCK associated with • 1) L-TGA• 2) HETEROTAXY• 3) AUTOIMMUNE DUE TO ANTI Ro/Sa

• Autoimmune fetal AV block can be treated with maternal administration of dexamethasone and/or sympathomimetic agents

• Efficacy of this combination doubtful

OTHER PHARMACOLOGICAL FCI INDICATION

• Fetal hydrops due to other structural cardiac anomalies• Transplacental treatment with digoxin

– Ebstein’s anomaly– Absent Pulmonary valve syndrome– Right heart dysfunction from left heart disease– Premature closure of the ductus arteriosus– Cardiac tumor– Cardiomyopathy

• Efficacy of digoxin not known

OPEN FETAL CARDIAC INTERVENTION

• “Open FCI” denotes any intervention in which the uterus is opened surgically or

accessed through a surgical trochar 3 mm in diameter, which includes most

fetoscopic techniques

• The first reported open FCI procedure in a human fetus was pacemaker placement

for complete AV block

CLOSED FETAL CARDIAC INTERVENTION

• Denotes mechanical interventions in which the uterus is not opened or accessed with a port > 3 mm in diameter

• The first reported case of closed FCI was a balloon aortic valvuloplasty performed in 1989

FETAL AORTIC VALVULOPLASTY

• The most common closed FCI procedure

• Some patients with HLHS are diagnosed during the 2nd trimester with valvar AS and a normal-sized or dilated LV evolve into HLHS over the course of gestation

• In other fetuses diagnosed with AS in midgestation, left heart growth and function will remain sufficient for a biventricular outcome

• Physiological features in favour of progression into HLHS– Retrograde flow in the transverse aortic arch– Severe LV dysfunction– Monophasic & short mitral inflow– Left to right flow through foramen ovale

FETAL AORTIC VALVULOPLASTY

• Aim of fetal aortic balloon valvuloplasty is to prevent progressive damage to the ventricular muscle and development of pulmonary vascular hypertension in utero

• This may allow a greater chance of surgical success postnatally

PROCEDURE• Fetal aortic balloon valvuloplasty is

performed at 21–32 weeks gestation

under maternal LA and sedation, by

inserting a needle through the

mother’s abdominal wall into the

uterine cavity under ultrasound

guidance

• Fetal position is important for

procedure success

• The potential benefit of FCI for evolving HLHS is that decreasing LV afterload or promoting flow through the left heart may prevent evolution to HLHS

• 75% to 80% technical success

• There is solid evidence that balloon dilation of the aortic valve in fetuses with AS and evolving HLHS improves left heart physiology and leads to improved growth of the aortic and mitral valves but has no apparent effect on LV growth per se

• COMPLICATIONS:• 1) Aortic regurgitation• 2) Fetal Bradycardia & Rv Dysfunction • 3) Hemopericardium• 4) Fetal death• 5) Premature labour

FETAL ATRIAL SEPTOSTOMY

INDICATIONS

• HLHS with restrictive ASD or intact IAS

• D-TGA

RATIONALE

• A restrictive atrial communication reduces the forward flow and increases the

reversed flow in the pulmonary veins at the time of atrial contraction

• This causes pulmonary congestion leading to chronic pulmonary hypertension

• This vascular damage is associated with increased 30-day mortality

PREDICTORS OF ATRIAL SEPTOSTOMY

• Ratios of forward-to-reverse flow in the pulmonary veins

• Absolute velocities of reversed flow

FETAL ATRIAL SEPTOSTOMY

• CATHETER INDUCED ATRIAL SEPTOSTOMY

TECHNICAL DIFFICULTIES

– 1) TAMPONADE - atrial wall is thin

– 2) Small balloon required as atria is small

– 3) Early closure of the small puncture site

• HIGH-INTENSITY FOCUSED ULTRASOUND (HIFU)

• Newer non invasive modality

• Uses ultrasound frequencies ranging from 500 kHz to 10 MHz to cause localized tissue

hyperthermia and damage remotely at predictable depths without injuring adjacent

tissue

FETAL PULMONARY VALVULOPLASTY

• PULMONARY ATRESIA WITH INTACT IVS, SEVERE PS WITH INTACT SEPTA

• RATIONALE• Fetuses having pulmonary atresia with intact IVS show right heart hypoplasia with an

overall 5-year survival of only 65% in a large population-based series• There is significant morbidity, and postnatal bi-ventricular circulation can be achieved

in only 32-55%• Intervention offered to prevent or slow progression of ventricular hypoplasia during

the 2ND and 3RD trimesters and to optimize right (and left) ventricular function• especially when there is severe TR & fetal hydrops

FETAL PULMONARY VALVULOPLASTY

INDICATION • Decreased biventricular cardiac output• Severe pulmonary stenosis and/or elevated RV pressure (TR jet)• Hydrops

• PROCEDURE• Performed at 21–32 weeks gestation LA with USG guidancxe• Fetal analgesic is then injected before advancing the needle through the fetal

chest wall into the right ventricular infundibulum of the fetus• A guidewire is inserted through the needle and across the pulmonary valve.• A balloon catheter is inserted and then inflated to dilate the stenotic valve • The catheter and needle are then withdrawn

Fetal intervention for cardiac disease: The cutting edge of perinatal care.Seminars in Fetal & Neonatal Medicine (2007

OUTCOMES

Fetal intervention for cardiac disease: The cutting edge of perinatal care.Seminars in Fetal & Neonatal Medicine (2007) 12,

FETAL PACING• Congenital heart block is responsible for fetal heart failure and hydrops with > 80%

mortality

• INDICATION• Fetus who is premature to be delivered and refractory to medical therapy

• Performed in only few cases with mixed results

Fetal intervention for cardiac disease: The cutting edge of perinatal care.Seminars in Fetal & Neonatal Medicine (2007)

OTHER FETAL THERAPIES

The Role of FetalEchocardiography in Fetal Intervention:A Symbiotic Relationship Clin Perinatol 36 (2009) 301–327

SUMMARY

• Comprehensive fetal echocardiography can increase detection rate of subtle CHD

by up to 60%, if performed in a systematic, methodical manner

• Ideal time -18-22 weeks

• First trimester echo features like nuchal fold thickness , TR etc help in early

detection

• Maternal and fetal indications for fetal echo

• Fetal therapy is a developing field with discovery of newer and effective

interventions

THANK YOU

• Fetal echo is ideally done during

• A) 12-15 weeks

• B) 15- 18 weeks

• C) 18-22 weeks

• D) 22-26 weeks

• NUCHAL FOLD THICKNESS THAT IS ASSOCIATED WITH MAXIMUM INCIDENCE OF

CHD

• A) 1.5mm

• B) 2.0 mm

• C) 3.0 mm

• D) 3.5 mm

• First trimester abnormalities that can predict CHD are all except

• A) TR

• B) Foramen ovale with right to left flow

• C) nuchal fold thickness> 3.5 mm

• D) reversal of a wavein ductus venosus doppler

• Fetal tachycardia is diagnosed if fetal heart rate is

• A)110• B)170• C) 150• D) 120

• Early fetal echo is done at• A) 4-7 weeks• B) 7-10 weeks• C) 11- 14 weeks• D) 14-18 weeks

Predictors of progression of valvular AS into HLHS are all excepta)Retrograde flow in the transverse aortic archb)Severe LV dysfunctionc)Monophasic & short mitral inflowd)Right to left flow through foramen ovale

• All are true of fetal therapy in fetal tachycardia except

• A)AVRT is the most common SVT

• B)Digoxin is drug of choice

• C) Hydrops is an indication

• D) Intermittent tachycardia should be terminated

• Fetal bradycardia is diagnosed if heart rate is• A)110• B) 120• C)130• D)140

• All are true except in Indication for fetal therapy in congenital AV block

• A) Indicated if ventricular rate is < 55/mt

• B) Presence of fetal hydrops

• C) Dexamethazone and sympathomimetic are used in autoimmune AV block

• D) Transcutaneous pacing is the FCI of choice in AVblock