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VII. Myocardial and Pericardial Abnormalities

VII. Myocardial and Pericardial Abnormalities

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Diagnostic Imaging Obstetrics, 2nd Edition







40% aneuploidy with fetal diagnosis

Excellent early and long-term outcomes if normal chromosomes

o 73-88% survival at 5-8 years

 26-42% of children will need reoperation at some point after primary repair

o More likely with outflow tract obstruction

Treatment

 Offer karyotype

 Offer termination if trisomy, multiple anomalies

 Prenatal consultation with pediatric cardiology/neonatology

 Deliver at tertiary center

 Immediate management depends on associated lesions

o Significant pulmonary stenosis → duct dependent → may need prostaglandins

 Timing and type of corrective surgery depends on

o Great artery relationship

o Presence and type of VSD

 VSD closure for subaortic VSD

 Arterial switch in DORV with aorta anterior and a subpulmonary VSD (Taussig-Bing)

o Associated lesions

 Single ventricle palliation for mitral atresia

 Goal of correction is to reestablish LV as systemic ventricle and repair all associated lesions

DIAGNOSTIC CHECKLIST

Image Interpretation Pearls

 Parallel outflow tracts = DORV or TGA

o Difference in ventriculoarterial relationship is key

o Final diagnosis may not be possible until after delivery

SELECTED REFERENCES

1. Obler D et al: Double outlet right ventricle: aetiologies and associations. J Med Genet. 45(8):481-97, 2008

2. Bradley TJ et al: Determinants of repair type, reintervention, and mortality in 393 children with doubleoutlet right ventricle. J Thorac Cardiovasc Surg. 134(4):967-973, 2007

3. Kim N et al: Diagnosis and prognosis of fetuses with double outlet right ventricle. Prenat Diagn.

26(8):740-5, 2006



VII. Myocardial and Pericardial Abnormalities

101. Echogenic Cardiac Focus

> Table of Contents > Section 6 - Heart > Myocardial and Pericardial Abnormalities > Echogenic Cardiac

Focus

Echogenic Cardiac Focus

Roya Sohaey, MD

Key Facts

Imaging

 Bright dot in ventricle of heart

o Should be bright as bone to be true finding

o Small (< 3 mm)

o 78% left, 18% right, 4% bilateral

o Multiple large and bilateral ECF have ↑ risk for aneuploidy compared to single ECF

 ECF is most often an incidental, isolated finding

 ECF association with trisomy 21 (T21)

o 1.2-2.8 likelihood ratio when isolated

o Seek other markers for T21

 ECF associated with trisomy 13 (T13)

o Associated cardiac anomaly common

o Other noncardiac anomalies also typically seen

Top Differential Diagnoses

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Rhabdomyoma

o Multiple echogenic masses in heart

 Atrioventricular (AV) septal defect

o Valve remnants can mimic ECF

Pathology

 Microcalcification within papillary muscle of heart

Clinical Issues

 Significant ethnic variability

o 10-30% of all Asian fetuses have ECF

 18% of fetuses with T21 have ECF

 39% of fetuses with T13 have ECF

Diagnostic Checklist

 Isolated ECF in low-risk patient almost always a normal finding

o Genetic testing usually not warranted

 Assess maternal risk for aneuploidy

o Maternal age

o Serum screening results



(Left) Ultrasound shows the typical appearance of an incidental, isolated echogenic cardiac focus (ECF) in a

lowrisk patient. A bright dot

, as bright as bone

, is seen in the left ventricle. This is generally of no

consequence and does not warrant genetic testing. It should, however, prompt a search for other markers

of aneuploidy. (Right) Two echogenic foci are present

, one in each ventricle of the heart. Bilateral and

multiple ECF are associated with increased risk for aneuploidy, compared to a single ECF.



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(Left) Axial ultrasound shows multiple, bilateral ECF

in a fetus with multiple other anomalies.

Amniocentesis revealed trisomy 13. (Right) Axial ultrasound shows ECF in association with a cardiac defect

(atrioventricular septal defect). The heart

is displaced to the right hemithorax because of a leftsided

diaphragmatic hernia. There is a right ventricle ECF

and a ventricular septal defect

. An ECF in

conjunction with heart anomalies is more suggestive of aneuploidy.

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TERMINOLOGY

Abbreviations

 Echogenic cardiac focus (ECF)

Synonyms

 Intracardiac echogenic focus (IEF)

 Echogenic intracardiac focus (EIF)

Definitions

 Focal echogenicity of papillary muscle

IMAGING

General Features

 Best diagnostic clue

o Bright dot in ventricle of heart

 Location

o 78% left, 18% right, 4% bilateral

 Size

o Small (< 3 mm)

Ultrasonographic Findings

 Bright echogenic focus in ventricle

o Should be bright as bone to be true finding

 Seen best when cardiac apex points up toward transducer

o Most often only single ECF seen

 Multiple large and bilateral ECF have ↑ risk for aneuploidy compared to single ECF

o ECF is usually an incidental isolated finding

 ECF association with trisomy 21 (T21)

o 1.2-2.8 likelihood ratio (LR) when isolated

 1.2-2.8x higher risk for T21 than a priori risk

 Rarely turns low-risk patient into high-risk patient

o Seek other markers for T21

 Nuchal thickening

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Short femur/short humerus

Echogenic bowel

Renal pelviectasis

o Resolution of ECF does not change risk

 ECF associated with trisomy 13 (T13)

o Associated cardiac anomaly common

 Hypoplastic left heart + ECF

o Other noncardiac anomalies also typically seen

Imaging Recommendations

 Best imaging tool

o Routine 4 chamber heart view

 Protocol advice

o Beware of pitfalls

 Normal papillary muscle (not as bright as bone)

 Moderator band (at apex of right ventricle)

o Assess maternal a priori risk for T21 and T13

 Maternal age and quadruple serum test results

 Amniocentesis usually not indicated

DIFFERENTIAL DIAGNOSIS

Rhabdomyoma

 Homogeneous echogenic cardiac tumor

o Originates from septum, ventricular wall, or atria

o Multiple tumors common

 50-85% have tuberous sclerosis

Atrioventricular Septal Defect

 Lack of central cardiac structures

 Lateral remnants of mitral and tricuspid valve can mimic ECF

 Highly associated with T21

PATHOLOGY

General Features

 Etiology

o Microcalcification within papillary muscle of heart

 Genetics

o Associated with T21 and T13

CLINICAL ISSUES

Presentation

 Most common signs/symptoms

o Incidental finding in low-risk patient

o Seen with other markers of T21

o Seen with severe anomalies of T13

Demographics

 Epidemiology

o Ethnic variability

 10-30% of Asian fetuses have ECF

 7% of African-American fetuses have ECF

 4% of Hispanic fetuses have ECF

 3% of Caucasian fetuses have ECF

o 18% of fetuses with T21 have ECF

o 39% of fetuses with T13 have ECF

Natural History & Prognosis

 Excellent prognosis in low-risk patients

DIAGNOSTIC CHECKLIST

Consider

 Isolated ECF in low-risk patient almost always a normal finding

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Image Interpretation Pearls

 Do not diagnose ECF if echogenicity is less than bone

o Turn down gain until all that is seen is ECF and bone to confirm true finding

SELECTED REFERENCES

1. Kirbiyik O et al: Intracardiac echogenic focus and cytogenetic abnormalities. Genet Couns. 20(1):73-5,

2009

2. Shanks AL et al: Echogenic intracardiac foci: associated with increased risk for fetal trisomy 21 or not? J

Ultrasound Med. 28(12):1639-43, 2009

3. Borgida AF et al: Frequency of echogenic intracardiac focus by race/ethnicity in euploid fetuses. J Matern

Fetal Neonatal Med. 18(1):65-6, 2005

4. Coco C et al: An isolated echogenic heart focus is not an indication for amniocentesis in 12,672

unselected patients. J Ultrasound Med. 23(4):489-96, 2004

5. Doubilet PM et al: Choroid plexus cyst and echogenic intracardiac focus in women at low risk for

chromosomal anomalies: the obligation to inform the mother. J Ultrasound Med. 23(7):883-5, 2004

6. Filly RA et al: Choroid plexus cyst and echogenic intracardiac focus in women at low risk for chromosomal

anomalies. J Ultrasound Med. 23(4):447-9, 2004



102. Hypertrophic Cardiomyopathy

> Table of Contents > Section 6 - Heart > Myocardial and Pericardial Abnormalities > Hypertrophic

Cardiomyopathy

Hypertrophic Cardiomyopathy

Michael D. Puchalski, MD

Key Facts

Terminology

 Primary disorder of cardiac muscle

o Thickened but nondilated left ventricle

o Absence of another cardiac or systemic disease capable of producing hypertrophy

 Genetic cardiac disease with heterogeneous expression, unique pathophysiology, and diverse

clinical course

Imaging

 Hypertrophy of myocardium

o Characteristically asymmetric in distribution (septum most often involved)

o May be symmetric (concentric hypertrophy)

 ± cardiomegaly

 Normal or hyperdynamic function

 Increased gradient in left ventricular outflow tract

o Delayed upstroke suggesting dynamic obstruction

o Due to systolic anterior motion of mitral valve

Pathology

 Myocardial hypertrophy may be end result of numerous disease processes

o Maternal diabetes mellitus

o Genetic causes

o Metabolic causes

o Fetal renal disease

o Twin-twin transfusion syndrome

Clinical Issues

 1:500 live births or 0.2% in general population

 Overall mortality rate: 52%

o Survival depends on underlying condition with fetus of diabetic mother typically doing best

 Limited treatment options with main goal to correct underlying condition if possible



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(Left) Long axis echocardiogram in this fetus shows a thick LV free wall

and septum

of unknown

etiology. Genetic counseling should be considered in cases such as this, as numerous genetic disorders

have been implicated as a cause of hypertrophic cardiomyopathy. (Right) Four chamber view

echocardiogram shows a small pericardial effusion

and biventricular hypertrophy

in this fetus of a

diabetic mother.



(Left) Gross pathology of a cross section of the left ventricle shows severe hypertrophy. This is asymmetric

hypertrophy with the basal anterior portion of the septum

being more involved than the free wall

.

(Right) Echocardiogram shows severe concentric left ventricular hypertrophy

. Note the small

ventricular cavity

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TERMINOLOGY

Abbreviations

 Hypertrophic cardiomyopathy (HCM)

Synonyms

 Idiopathic hypertrophic subaortic stenosis (IHSS)

 Hypertrophic obstructive cardiomyopathy (HOCM)

Definitions

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Primary disorder of cardiac muscle

o Thickened but nondilated left ventricle (LV)

o Absence of another cardiac or systemic disease capable of producing hypertrophy

 Genetic cardiac disease with heterogeneous expression, unique pathophysiology, and diverse

clinical course

IMAGING

General Features

 Best diagnostic clue

o Thickened myocardium

Echocardiographic Findings

 Grayscale

o Hypertrophy of myocardium

 Characteristically asymmetric in distribution

 Septum most often involved

 May be confined to apex or free wall

 May be symmetric (concentric hypertrophy)

 May be normal or near normal LV wall thickness

o ± cardiomegaly

o Normal or hyperdynamic function

 Pulsed Doppler

o Increased gradient in left ventricular outflow tract

 Delayed upstroke suggesting dynamic obstruction

 Due to systolic anterior motion (SAM) of mitral valve

 Color Doppler

o Signs of mid-cavitary obstruction

 Turbulent flow in left ventricular outflow from subaortic stenosis or SAM of mitral

valve

Imaging Recommendations

 Protocol advice

o If myocardium appears thickened

 Assess for involvement of both ventricles

 Assess whether it is symmetric or asymmetric in LV

 Exclude mechanical causes

 Valvar stenoses

 Ductal constriction

 Coarctation (may not be able to exclude this in fetus)

o Measure ventricular wall thickness

 Measure at level of papillary muscles

 Epicardial to endocardial surface at end-diastole

o Measure chamber dimensions in 4 chamber view

 End-diastolic diameter (EDD) is longest measurement at end-diastole

 End-systolic diameter (ESD) is shortest measurement at end-systole

o Measure function by ventricular shortening fraction (VSF)

 VSF = EDD — ESD/EDD

 Normal right VSF: 0.25, normal left VSF: 0.30

o Look for signs of embryopathy in fetus of diabetic mother

 Caudal regression sequence

 Central nervous system anomalies particularly holoprosencephaly spectrum

DIFFERENTIAL DIAGNOSIS

Outflow Tract Obstruction

 Left ventricular outflow tract obstruction

o Aortic atresia/stenosis

o Hypoplastic left heart syndrome

 Pulmonary stenosis/atresia

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Ductal constriction

Rhabdomyoma

 Mimics HCM if it involves ventricular septum

 Usually multiple masses

PATHOLOGY

General Features

 Etiology

o Myocardial hypertrophy may be end result of numerous disease processes

 Maternal diabetes mellitus

 50% type 1

 25% type 2

 Rare in gestational diabetics

 Metabolic causes

 B lipase deficiency

 Cytochrome oxidase deficiency

 Fetal renal disease

 Renal agenesis

 Multicystic kidneys

 Congenital nephrotic syndrome

 Twin-twin transfusion syndrome (TTTS)

 Increased work for pump twin heart, recipient has volume overload

 Either/both may develop ventricular hypertrophy

 If untreated, ultimately progresses to dilated end-stage heart disease

o Other high-output states

 Anemia, vascular malformations, masses (e.g., sacrococcygeal teratoma)

 Genetics

o Familial HCM

 50% have mutation of chromosome 1, 14, or 15

 30% missense mutation in cardiac β myosin heavy chain gene on chromosome

14q11

 15% mutation in cardiac troponin T gene on chromosome 1q3

 3% mutation in α tropomyosin gene on chromosome 15q2

o Noonan syndrome: Only single gene disorder likely to be diagnosed in utero

 LEOPARD syndrome: Related but caused by different missense mutation of same

gene

o Other chromosomal abnormalities

 Friedrich ataxia

 Timothy syndrome

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Costello syndrome

Pompe disease







Physiology

o Ventricular walls and septum are thick

o Thick myocardium is stiff

o ↓ compliance → ↓ filling → ↓ cardiac output

 Hypertrophic CM may cause diastolic dysfunction

o Myocardial perfusion occurs in diastole

o Diastolic dysfunction → myocardial ischemia/myopathy

o Ischemia may → ventricular dilatation and cardiomegaly

Microscopic Features

 Pompe disease

o Muscle fibers infiltrated with glycogen

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o



Individual muscle fibers massively hypertrophied

CLINICAL ISSUES

Presentation

 Most common signs/symptoms

o Most primary/familial cases present in 3rd trimester

o Fetuses of diabetic mothers may show progressive increase in heart size/myocardial

thickness from 2nd trimester onward

o Cases due to high-output state present earlier due to underlying condition

Demographics

 Epidemiology

o HCM: 1:500 live births or 0.2% in general population

o Series of 55 cases fetal CM

 40% dilated CM

 60% hypertrophic CM

o Of 33 hypertrophic CM cases

 54%TTTS

 21% fetus of diabetic mother

 6% Noonan syndrome

 3% familial hypertrophy

Natural History & Prognosis

 Depends on underlying condition

o Overall mortality rate in series: 52%

 33% died in utero and remainder in neonatal period

o Presence of diastolic dysfunction had 8x increase risk of mortality

 Fetus of diabetic mother

o Disproportionate thickening of ventricular septum or free wall

 Progressive but tends to occur after 30 weeks gestation

 Usually resolves spontaneously after birth with few patients being symptomatic

 Primary/familial forms

o Annual risk of death: 1%

o Normal fetal echocardiogram does not imply disease-free lifetime

 Familial forms may not have clinical impact until adolescence or later

 Recipient in TTTS with HCM

o Mortality of 65%

o Survivors all had resolution of hypertrophy by 3 months of age

 Some HCM cases progress to dilated cardiomyopathy if underlying condition not treated

Treatment

 Detailed family history

o Consider echocardiography of parents if mother not diabetic

o Genetic testing possible for some types

 Ethical dilemma as presence of mutation does not = presence of disease

o Inborn errors of metabolism often autosomal recessive

 May require specific treatment/dietary measures

 Correct underlying conditions

o Laser/radiofrequency ablation for TTTS or twin reversed arterial perfusion (TRAP)

o Fetal surgery for tumors such as sacrococcygeal teratoma

o Intrauterine transfusion for fetal anemia

 Monitor throughout pregnancy

o Hypertrophy may be progressive → secondary outflow obstruction

 Refer to tertiary center

o Delivery plan coordinated with neonatology/pediatric cardiology

o Careful postnatal evaluation

 Accurate diagnosis important to counsel parents on prognosis/recurrence risk

o Postnatal treatment options may be few

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Diagnostic Imaging Obstetrics, 2nd Edition







Consider implantable cardiac defibrillator in highrisk patients

Cardiac transplantation is last resort



DIAGNOSTIC CHECKLIST

Consider

 Formal fetal echocardiography in all cases

o Exclude structural malformation

o Assess baseline function

Image Interpretation Pearls

 Always check for mechanical obstruction

 In at-risk fetus, measure ventricular shortening fraction

 Impaired diastolic function may be more important than systolic dysfunction

SELECTED REFERENCES

1. Ullmo S et al: Pathologic ventricular hypertrophy in the offspring of diabetic mothers: a retrospective

study. Eur Heart J. 28(11):1319-25, 2007

2. Abu-Sulaiman RM et al: Congenital heart disease in infants of diabetic mothers: echocardiographic study.

Pediatr Cardiol. 25(2):137-40, 2004

3. Barth PG et al: X-linked cardioskeletal myopathy and neutropenia (Barth syndrome): an update. Am J

Med Genet A. 126(4):349-54, 2004

4. Karatza AA et al: Isolated non-compaction of the ventricular myocardium: prenatal diagnosis and natural

history. Ultrasound Obstet Gynecol. 21(1):75-80, 2003

5. Pedra SR et al: Fetal cardiomyopathies: pathogenic mechanisms, hemodynamic findings, and clinical

outcome. Circulation. 106(5):585-91, 2002

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Image Gallery



(Left) Echocardiogram of a fetus of a diabetic mother shows marked thickening of the ventricular septum

(calipers). The ventricular free walls are also hypertrophied with the LV

being more severely involved

than the RV

. (Right) Four chamber view echocardiogram shows systolic anterior motion (SAM) of the

mitral valve

causing almost complete obliteration of the left ventricular outflow tract

as it opposes

the prominent septal hypertrophy

.



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Diagnostic Imaging Obstetrics, 2nd Edition



(Left) Four chamber view color Doppler echocardiogram in the same patient shows turbulent flow

(representing obstruction) where the anterior mitral valve meets the septum. This is well below the

level of the aortic valve

. (Right) Matching continuous wave Doppler echocardiogram in the LVOT shows

moderate to severe obstruction with a gradient of 66 mmHg. The wave form has the classic late systolic

accentuation

characteristic of dynamic obstruction.



(Left) T2WI MR in the 4 chamber plane shows the ventricular septum

with significant hypertrophy

compared to the free wall

consistent with asymmetric HCM. (Right) LVOT view in a postnatal

echocardiogram shows severe asymmetric septal hypertrophy, which apposes the anterior leaflet of mitral

valve (MV)

causing left ventricular outflow tract obstruction. (LA = left atrium)



103. Dilated Cardiomyopathy

> Table of Contents > Section 6 - Heart > Myocardial and Pericardial Abnormalities > Dilated

Cardiomyopathy

Dilated Cardiomyopathy

Michael D. Puchalski, MD

Key Facts

Terminology

 Myocardial disease not usually associated with structural or pericardial malformations

 Dilated heart with decreased systolic function

 Final common pathway for diverse disease processes that lead to heart failure

Imaging

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