Introduction Dilated Cardiomyopathy is an important cause of heart failure in children. It often has an idiopathic aetiology, but may also be caused by infection and can be inherited. Hypocalcaemia is a rare but important reversible cause of dilated cardiomyopathy. Vitamin D deficiency is the main cause of hypocalcaemia in almost all reported cases.
Case Report: An 8 month-old, Afro-Caribbean boy, presented with acute heart failure and respiratory distress. He was born in the UK and exclusively breastfed until 6 months of age. Cardiovascular examination revealed a gallop rhythm and a grade 2/6 pan systolic murmur at the apex, with a 2cm liver edge palpable. There was clinical evidence of rickets.
Investigations included a chest X-ray, which showed cardiomegaly and plethoric lung fields. ECG showed increased left ventricular voltages and a prolonged QTc interval. Venous blood gas revealed a metabolic acidosis and a low ionised calcium level (0.6mMol/l). Echocardiogram revealed a poorly functioning and dilated left ventricle with severe mitral regurgitation. Hypocalcaemia secondary to severe vitamin D deficiency was diagnosed by screening blood tests. In addition to supportive treatment for cardiac failure (furosemide and captopril) he was treated with alphacalcidiol and Calcium-Sandoz.
Echocardiogram 2 months later showed a near normal left ventricular function with a well contracting ventricle. His biochemical profile normalised within 4 weeks of treatment.
Discussion Nutritional vitamin D deficiency leading to dilated cardiomyopathy has been increasingly reported, and indicates it as an important aetiology to consider in heart failure. A recent retrospective review showed that such infants can present in extremis, requiring inotropic and ECMO support. However, compared to other cardiomyopathies, there is a relatively good prognosis, with a mean recovery of left ventricular shortening reported at 12.4 months.1
Rickets itself has seen a resurgence, especially in developed countries2 This is a preventable condition, but obstacles3,4 have been reported, despite NICE5 and DoH6 guidelines for antenatal care, post-natal supplementation and clinical management.
Conclusion This case represents a serious consequence for undiagnosed vitamin D deficiency. In view of its preventable nature, healthcare professionls should have greater awareness. This has been supported by the recent RCPCH position statement calling for practical sign-posting.7