THE BEST KNOWN clinical effect on the heart of hypocalcemia is prolongation of the QT interval, ie, prolongation of electrical systole.1-6 Only recently has cardiac arrhythmia been reported as a clinical manifestation of hypocalcemia.7,8 This report describes a child with hypocalcemic vitamin D deficient rickets who presented with bizarre cardiac arrhythmias which were corrected following oral calcium and vitamin D2 therapy.
Report of a Case
This 5½-year-old Negro boy was admitted to the Johns Hopkins Hospital because of tachycardia discovered during a routine visit to the cardiac clinic. He had been followed by the Growth and Development Program of Johns Hopkins Hospital since age 4 months, and had been noted to have marked motor and mental retardation. In addition, a heart murmur had been heard consistently since 1 year of age. Previous chest x-ray films had revealed mild cardiac enlargement and an electrocardiogram had shown right ventricular