Cardiac arrest under anesthesia in a pediatric patient with Williams syndrome: a case report.

Serial cardiac arrests occurred during the induction of a 3-year-old boy for elective 1-sided orchiopexy surgery and evaluation under anesthesia of previously placed ear tympanoplasty tubes. The child's history included Williams syndrome along with hypercalcemia and mild supravalvular aortic stenosis. The initial arrests included significant ST wave changes along with profound brodycardia, hypotension, and pulseless electrical activity requiring full resuscitation twice. The patient was transferred on an emergency basis to the intensive care unit (the surgery was cancelled), and a heart catheterization was scheduled for the following morning. The patient experienced several cardiac arrests during the cardiac catheterization procedure, necessitating emergency extracorporeal membrane oxygenation cannulation and immediate transfer to the operating room for emergency cardiac surgery. A thorough preoperative cardiac workup, including cardiac catheterization, electrocardiogram, and echocardiogram, may decrease mortality and morbidity in patients with Williams syndrome. However, cardiac catheterization has been associated with increased risk in this patient population.