Idiopathic arterial calcification and unexpected infant death

Two infants who died unexpectedly and who were found at autopsy to have idiopathic arterial calcification are presented. The first infant died within hours of the sudden onset of shortness of breath. The second infant died suddenly and unexpectedly in hospital where he was being treated for presumed sepsis and cardiac failure. Neither infant had significant past or family histories. Autopsy examination in both infants demonstrated widespread fibrointimal proliferation of elastic and muscular arteries with characteristic calcification of the internal elastic laminae. Kidneys and parathyroid glands were normal. Death in case 1 was attributed to extensive myocardial ischemic damage with right coronary artery ostial stenosis due to idiopathic arterial calcification. Death in case 2 was attributed to saddle pulmonary thromboembolism arising from a right atrial thrombus associated with cardiac failure secondary to idiopathic arterial calcification. These cases demonstrate the variable presentations, causes of death, and autopsy findings that may occur in this uncommon condition.