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LEFT VENTRICULAR NON- COMPACTIONSHORT REVIEW

DR MAHENDRACARDIOLOGY,JIPMER

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INTRODUCTION

• Spongy appearance of the myocardium first described by Grant in 1926.

• Developmental considerations-• development of the myocardial architecture which passes

through four distinct steps• (i) early heart tube • (ii) emergence of trabeculations• (iii) trabecular remodeling• (iv) development of the multilayered spiral system• Emergence of trabeculations and trabecular remodeling are

the key steps to understand LVNC

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• Emergence of trabeculations-• emerge after looping of the primitive heart tube at the end of

the fourth week of gestation. • trabeculation patterns are ventricle-specific• trabeculations in the LV are generally thicker and the

corresponding intertrabecular spaces are larger at this embryonic stage.

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• Trabecular remodeling-• remodelling starts after completion of ventricular septation at

8 weeks of gestation in human.• Increase in ventricular volumes results in compression of the

trabeculations with an increase in the thickness of the compacted myocardium.

• compaction process coincides with the invasion of epicardial coronary arteries and vascularization of the myocardium

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• progresses from-• epicardium to the endocardium • base to the apex • septum to the free wall in the LV• more in LV than right ventricle• time of arrest of normal embryonic myocardial maturation

determines the severity and extension of LVNC

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• Left ventricular noncompaction cardiomyopathy rare congenital disorder characterized by

1. Prominent LV trabeculae2. Deep intertrabecular recesses communicate with venricular

cavity3. Thin compacted layer4. Noncompacted and compacted ratio >2 in end systole

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• persistent sinusoids• describe ventriculo-coronary arterial communications or

intertrabecular spaces connecting the ventricular cavity with the epicardial coronary artery system through the capillary bed.

• seen in pulmonary atresia with intact ventricular septum.• hypertrabeculation- • increased number of normally formed trabeculations

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PREVALENCE• In adults based on Echo ranges fom 0.014% to 1.3%• In Australian children with cardiomyopathy prevalence higher-

5% to 9.2%.• phenotype of noncompaction can vary even within familial

cases and range from clinically benign to fatal.

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Genetics of LVNC• Sporadic and familial form. • AD more common than X-linked inheritance• Familial recurrence between 18 and 50% • Mutations in the G4.5 gene on Xq28 resulting Barth syndrome

with DCM and LVNC in a pediatric population.• Loci for LVNC were also described on chromosome 1, 5, and

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• Acquired NCLV-• Young athlete• Pregnancy• Sickle cell anemia

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CLASSIFICATION• AHA classifies LVNC as a genetic cardiomyopathy.• ESC and WHO classify LVNC as an unclassified

cardiomyopathy.

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Diagnostic criteria-

• Normal variants-• Boyd et al. reported the frequency and localization of

prominent LV trabeculations at autopsy in 474 normal hearts• 53% of them exhibited two or more. • More than three prominent trabeculations were observed in

only 3%. • but none of the hearts had more than five. • Most of the trabeculations (85%) were septomarginal bundles

inserting into both the free wall and the septum

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Non-compaction (California criteria)

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Zurich criteria

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Vienna criteria

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Limitations of echocardiographic criteria• poor correlation between three echocardiographic definitions• 24% of the study population fulfilled one or more

echocardiographic definitions for LVNC.• only 30% fulfilled all three criteria. • 8% of apparently healthy individuals also satisfied one or

more diagnostic criteria for LVNC• Contrast echocardiogram is useful to better image

intertrabecular spaces

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Cardiac magnetic resonance imaging

• Method of choice to confirm or rule out the diagnosis of LVNC• The NC areas are most commonly found in the apical and

lateral portions of the left ventricle• ratio of NC to C layers > than 2.3 at end diastole (Petersen et

al.)• Trabeculated LV mass >20% of global LV mass (Jacquier et al.)

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33Zuccarino et al. AJR:204 May 2015

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• Differential diagnosis-• Apical form of hypertrophic cardiomyopathy, a combination of

both apical hypertrophic cardiomyopathy and LVNC • hypertensive cardiomyopathy• endocardial fibroelastosis• abnormal chords• Apical thrombus, or tumours

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ASSOCIATED CONDITIONS• Coronary cameral fistulas• LVOT abnormalities• Ebstein’s anomaly• Bicuspid aortic valve• Transposition of great vessels• Metabolic diseases and genetic syndromes, including the

Barth syndrome, the Charco-Marie-Tooth disease• Muscular dystrophy

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MANAGEMENT• No specific treatment available• Family members of proband should be screened using ECHO• Genetic testing may useful in identifying familial forms

• Anticoagulation-(INR 2-3)1. Decreased systolic function with EF below 40%2. History of thromboembolism 3. Atrial fibrillation

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• ICD/biventricular pacing-• no robust data available for guideline• indication for device therapy as per current guideline.

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Take home message

• Many pt with trabeculae but normal LV function diagnosed as NVLC.

• Should not labeled unless truly meet diagnostic criteria.• Jenni criteria appear to best at present.• Trabeculation may progress or change under physiologic

condition like pregnancy, serial evaluation is necessary.• Difference in LV mass and trabecular feature between racial

background • Screening of relative is crucially important.

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THANK YOU