Hypocalcaemia and Vitamin D deficiency: an important, but preventable cause of life threatening infant heart failure

Abstract

Objectives: In recent large pediatric cardiomyopathy population studies from North America and Australia, vitamin D deficiency was not identified as a cause of infant heart failure. However, rickets is resurgent in developed countries. We sought to review the prevalence of this cardiomyopathy in pediatric cardiology units of South East England and determine the prognosis.

Methods and Results: A retrospective review from 2000-2006 in South East England. Sixteen infants (6 Indian subcontinent, 10 Black ethnicity) were identified: median (range) age at presentation was 5.3 months (3 weeks-8 months). All had been breast-fed. Ten presented at the end of the British winter (February-May). Median shortening fraction was 10% (range 5-18%) and median left ventricular end diastolic dimension z score was 4.1 (range 3.1-7.0). Six suffered a cardiac arrest. There were three deaths. Eight were ventilated, two required mechanical circulatory support and twelve required intravenous inotropic support. Two were referred for cardiac transplantation. Median (range) of biochemical values on admission were: total calcium 1.38 (1.07-1.74) mmol/l ; alkaline phosphatase 646 (340-1057) IU/l; 25Hydroxy vitamin D 18.5 (0-46) nmol/l (normal range >35) and parathyroid hormone 34.3 (8.9-102) pmol/l (normal range<6.1). All survivors have improved clinically and on echocardiographic indices. Mean time from diagnosis to achieve normal fractional shortening was 12.4 months.

Conclusions: Vitamin D deficiency and consequent hypocalcaemia are seen in association with severe and life threatening infant heart failure. That no infant or mother was receiving the recommended vitamin supplementation highlights the need for adequate provision of vitamin D to ethnic minority populations.