Preoperative management of hypoplastic left heart syndrome

Pediatricians are frequently involved in the care of cyanotic newborns in the labor and delivery room, as well as in the well baby nursery. Causes of hypoxia and cyanosis in the term newborn can be found within all physiological systems. Congenital heart structural diseases account for the largest diagnostic category. There have been significant advances during the past years in the diagnosis and treatment of neonates with critical congenital heart disease, especially in the field of pre- and post-operative intensive care. 

The term hypoplastic left heart syndrome (HLHS) describes a spectrum of cardiac structural abnormalities characterized by marked hypoplasia of the left ventricle and ascending aorta. Prenatal diagnosis, initial resuscitation and optimal preoperative management are key elements that allow the best opportunity for low mortality and normal neurodevelopment in affected newborns. Preoperatively, the goal is to achieve adequate systemic oxygen delivery. Patency of the ductus arteriosus (DA) is critical for survival until surgery. Blood flow to the pulmonary and systemic circulations should be nearly balanced (goal 

Qp/Qs ratio of 1). The immediate therapy for all infants with HLHS is an intravenous infusion of prostaglandin E1 (PGE1) in order to manipulate the DA and maintain ductal patency. Oxygen saturations of 75% to 85% by pulse oximetry suggest an adequate balance between systemic and pulmonary blood flow. Judicious use of inotropic support is initiated if evidence of low cardiac output is detected. Diuretics may be necessary to help alleviate the increased volume load on the right ven-tricle. The goal of respiratory management is to increase pulmonary vascular resistance and decrease systemic vascular resistance. Infants with HLHS who are born with a severely restricted or no inter-atrial communication, a rare occurrence, have profound hypoxemia. The severe restriction of blood flow across the atrial septum results in a life-threatening situati-on and these patients, which present with severe cyanosis and hemodynamic instability, require urgent postnatal cardiac catheterization to relieve the septal obstruction and improve oxygenation. Special attention should be paid to the prevention of brain injury and poor neurodevelopmental outcome. 

Care for infants with HLHS is complex, and often multiple specialists are involved. Despite an increase in the number of newborns with complex congenital heart disease and a growing percentage of patients with single-ventricle physiology, it is possible to care for this particular group of patients and achieve acceptable mortality risks, even in centres with no pediatric cardiac surgery facilities, if good preoperative management protocols are followed. 

congenital heart disease, newborn, intensive care, hemodyna-mics, PGE1, ductus arteriosus

1. Hall RJ, Nelson WP, Blake HA, Geiger JP. Massive Pulmonary Arteriovenous Fistula in the Newborn. Circulation 1965;31:762-7.

2. Izukawa T, Mullholland HC, Rowe RD, Cook DH, Bloom KR, Trusler GA, et al. Structural heart disease in the newborn. Arch Disease Chil-dhood 1979;54:281-5.

3. Ravinaskar C, Tabbutt S, Wernovsky G. Critical care in cardiovascular medicine. Curr Opin Pediatr 2003;15:443-53.

4. Baba K, Ohtsuki S, Kamada M, Kataoka K, Ohno N, Okamoto Y, et al. Preoperative management for tricuspid regurgitation in hypoplastic left heart syndrome. Ped Internat 2009;51:399-404.

5. Fricker FJ. Hypoplastic Left Heart Syndrome – Diagnosis and early management. NeoReviews 2008;9:253.

6. Hoffmann GM, Ghanayem NS, Kampine JM, Berger S, Mussatto KA, Litwin SB, et al. Venous saturation and the anaerobic threshold in neonates after the Norwood procedure for hypoplastic left heart syndrome. Ann Thorac Surg 2000;70:1515-21.

7. Singh GH, Fong LV, Salmon AP, Keeton BR. Study of low dosage prostaglandin – usages and complication. Eur Heart J 1994;15:377-81.

8. Lewis AB, Freed MD, Heymann MA, Roehl SL, Kensey RC. Side effects of therapy with prostaglandin E1 in infants with critical congenital heart disease. Circulation 1981;64: 893-8.

9. Thiebaud B, Michelakis E, Wu XC, Harry G, Hashimoto K, Archer SL. Sildenafil Reverses O2 constriction of the rabbit Ductus Arteriosus by inhibiting Type 5 phosphodisesterase and activating BK Ca Channels. Ped Res 2002;52:19-24.

10. Rychik J, Rome JJ, Collins MH, DeCampli WM, Spray TL. The hypoplastic left heart syndrome with intact atrial septum: atrial morphology, pulmonary vascular histopathology and outcome. J Am Coll Cardiol 1999;34:554-60.

11. Atz AM, Feinstein JA, Jonas RA. Preoperative management of pulmonary venous hypertension in hypoplastic left heart syndrome with restrictive atrial septal defect. Am J Cardiol 1999;83:1224-8.

12. Newburger JW, Jonas RA, Wernovsky G. A comparison of the preoperative neurologic effects of hypothermic circulatory arrest versus low-flow cardiopulmonary bypass in infant heart surgery. N Engl J Med 1993;329:1057-64.

13. Miller SP, McQuillen PS, Hamrick S, Xu D, Glidden DV, Charlton N. Abnormal brain development in newborns with congenital heart disease. N Engl J Med. 2007;357:1928-38.

14. Tabbutt S, Nord AS, Jarvik GP. Neurodevelopmental outcomes after staged palliation for hypoplastic left heart syndrome. Pediatrics 2008;121:476-83.

15. Dorfman AT, Marino BS, Wernovsky G, Tabbutt S, Ravishankar C, Godinez RI, et al. Critical heart disease in the neonate: Presentation and outcome at a tertiary care center. Pediatr Crit Care Med 2008;9:193-202.