Final Diagnosis -- Isolated Non-compaction of Left Ventricle

DISCUSSION

Left ventricular non-compaction (LVNC) -

• Rare cardiomyopathy now classified as primary genetic cardiomyopathy, related to alpha dystrobrevin, RyR2, G4.5 genes
• Synonyms - spongy heart, snake heart
• Incidence - About 0.12 per 100,000 children; 25%-44% of cases are familial; autosomal dominant with incomplete penetrance.
• It uniformly affects the left ventricle and sometimes the right ventricle.
• Characterized by persistence of prominent and coarse trabeculae, incomplete compaction of the myocardium and resultant spongy appearance
• It consists of numerous large mid-ventricular and apical trabeculae that project into the lumen and may be associated with structural cardiac defects.
• Patients usually present as dilated cardiomyopathy and heart failure.
• Complications include thromboemboli, arrhythmias and possibly myocardial infarction.
• Echocardiographic & pathoanatomical criteria for diagnosis:
  • Multiple trabeculations mainly in the mid and apical portions of the ventricle
  • Multiple intertrabecular recesses communicating with the ventricular cavity
  • Two layered structure of endocardium with increased noncompacted to compacted ratio (> 1.5 in children & > 2 in adults)

• The clinical manifestations of cardiac non-compaction may be different in children, overshadowed by the effects of associated cardiac defects.
• This case diagnosed at autopsy, satisfied most of the required criteria.
• Echocardiography has been the diagnostic procedure of choice, but the correct diagnosis is often missed or delayed because of lack of knowledge about this uncommon disease.
• There is a need for early and accurate diagnosis since it may entail screening of patient's family.

REFERENCES

1. R Jenni, E Oechslin, J Schneider, C Attenhofer Jost, P A Kaufmann Heart 2001; 86:666-671 Echocardiographic and pathoanatomical characteristics of isolated left ventricular non-compaction: a step towards classification as a distinct cardiomyopathy
2. Maron BJ, Towbin JA, Tiene G, Antzelevitch C, Corrado D, Arnett D,et al. Contemporary definitions and classification of the cardiomyopathies. Circulation 2006; 113: 1807-16.

QUESTIONS

1. What are the diagnostic criteria for left ventricular non-compaction (LVNC)?
   • Multiple trabeculations mainly in the mid and apical portions of the ventricle
   • Multiple intertrabecular recesses communicating with the ventricular cavity
   • Two layered structure of endocardium with increased noncompacted to compacted ratio (> 1.5 in children & > 2 in adults)
2. What are complications associated with LVNC?
   • Commonest complication is congestive heart failure, followed by thromboemboli, arrhythmias and possibly myocardial infarction.
3. Why is an early diagnosis of LVNC important?
   • Accurate diagnosis is important since it may entail screening of patient's family because 25%-44% of LVNC cases are familial, transmitted in a autosomal dominant fashion with incomplete penetrance.

   Contributed by Arivarasan Karunamurthy, MD.

   
   
   

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