Cardiac and extracardiac anomalies tend to follow characteristic patterns when there is an isomeric arrangement of the heart and lungs. We present a case diagnosed correctly during prenatal life as having isomerism of the left atrial appendages in which some of the associated features were most unexpected, namely absence of the spleen and obstructed totally anomalous pulmonary venous connection. This association proved misleading for us in the management of the patient. We found it difficult to believe our findings in the light of our past knowledge, and this resulted in a delay in the referral for surgery. The final outcome was unfortunately fatal. In the management of isomerism of any type, therefore, a wide spectrum of combinations and “crossover” of cardiac anomalies must be anticipated, emphasizing the need to assess individually the arrangement of the different organs of the body.

Isolated noncompaction of the myocardium, also known as “spongy myocardium”, is a rare disease in children and adults. It is suggested that, during early development of the heart, the primary spongy structure persists due to an arrest of compaction. No other cardiac malformations are found, but there are familial occurences, relations to genetic disorders or syndromes such as Melnick-needles-syndrome or Xq28-linked cardiomyopathy, and reports of conduction disorders.

We have now diagnosed isolated noncompaction in seven children aged between five weeks and 5.5 years. Three are doing well with anticongestive therapy, while transplantation of the heart was performed in one. Three of the children have died, but in only one case due to cardiac failure.

Our experience emphasises the need rapidly to establish the diagnosis, to search for associated extracardiac abnormalities, and to consider transplantation at an early stage.