fetal echo & fetal therapies dr sandeep.r sr cardio
TRANSCRIPT
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