Letter by Sane Regarding Article, “New-Onset Heart Failure Due to Heart Muscle Disease in Childhood: A Prospective Study in the United Kingdom and Ireland”
To the Editor:
Andrews and colleagues1 reported a prospective population-based study of first episode of “heart muscle disease–induced” heart failure in children <16 years of age. The case frequency averaged 0.87 per 100 000 but varied by >7-fold from Wales (0.17 per 100 000) to Scotland (1.27 per 100 000). The most common reported causes of heart failure were idiopathic and probable myocarditis. A single case of rickets-associated heart failure was reported. It is likely that vitamin D deficiency was underdiagnosed. Vitamin D deficiency with hypocalcemia has been reported to cause heart failure in infants without radiographic manifestations of rickets.2 The increased frequency at higher latitudes reported in this study,1 as well as the higher incidence in New England compared with the Central Southwestern United States,3 is a finding consistent with vitamin D deficiency. Furthermore, black children, who are more prone to vitamin D deficiency, have higher rates of cardiomyopathy than whites.3 The vitamin D receptor is present in cardiomyocytes and when ligated with activated vitamin D elicits calcium current through L-type voltage-gated calcium channels.4 In response to activated vitamin D, isolated cardiomyocytes exhibit reduced time to peak shortening and relaxation.4 Thus, deficiency of vitamin D could masquerade as an idiopathic or intrinsic “heart muscle disease.” Furthermore, vitamin D regulates immune and antimicrobial responses,5 with a corollary that deficiency could be manifest as “myocarditis.” Because Vitamin D deficiency is easily correctable, pediatric patients with “heart muscle–induced” heart failure should be screened by measuring 25-hydroxy-vitamin D levels.
Andrews RE, Fenton MJ, Ridout DA, Burch M; on behalf of the British Congenital Cardiac Association. New-onset heart failure due to heart muscle disease in childhood: a prospective study in the United Kingdom and Ireland. Circulation. 2008; 117: 79–84.
Maiya S, Sullivan I, Allgrove J, Archer N, Tulloh R, Daubeney P, Malone M, Mok Q, Yates R, Brain C, Burch M. Hypocalcaemia and Vitamin D deficiency: an important, but preventable, cause of life-threatening infant heart failure. Heart. 2008; 94: 581–584.