The Journal of Pediatrics
Volume 152, Issue 4 , Pages 456-457, April 2008

Hypoplastic Left Heart Syndrome—The Rest of the Story

  • Reginald L. Washington, MD (Chief Medical Officer)

      Affiliations

    • Corresponding Author InformationReprint requests: Reginald L. Washington, MD, Chief Medical Officer, Rocky Mountain Hospital for Children, Denver, CO.

Rocky Mountain Hospital for Children, Clinical Professor of Pediatric Cardiology, University of Colorado School of Medicine, Denver, Colorado

Article Outline

 

The prevalence of hypoplastic left heart is approximately 0.162 per 1000 live births.1 Hypoplastic left heart syndrome (HLHS) remains a very serious and difficult problem. Before 1980, 90% of these affected children died within the first 30 days of life.2 Most of those infants had normal neonatal examinations and were discharged to home, where they later developed feeding difficulties and respiratory distress. Most of these infants presented in a moribund state, often pulseless, with very poor perfusion and a relentless metabolic acidosis. These infants quickly expired after patent ductus arteriosus (PDA) closure.

See related article, p 507

In the era before routine echocardiographic imaging and pharmacologic manipulation of the PDA, any infants with HLHS admitted to the hospital had to be diagnosed through cardiac catheterization. All too often, the catheterization itself caused profound bradycardia and terminal dysrhythmias. The application of M-mode echocardiography in the mid-1970s, followed by two-dimensional echocardiography in the 1980s, virtually replaced invasive diagnostic measures. Despite a more rapid diagnosis, however, HLHS remained a fatal condition until the initiation of prostaglandin administration to maintain the patency of the ductus arteriosus and allow better perfusion to the lower body, including the kidneys.

It was just 25 years ago that Norwood et al3, 4 reported the successful staged palliation of a patient with aortic atresia using Fontan’s procedure. This remains a high-risk procedure, however, with the highest mortality during and after first-stage palliation (10% to 30%).5 Outcomes continue to improve with early diagnosis using fetal echocardiography as a diagnostic tool, along with preoperative stabilization, early repair, and increased monitoring after discharge.6

While the Norwood procedure was being developed, Bailey et al7 transplanted a baboon heart into Baby Fay, a newborn with HLHS. Although the infant did not survive, this procedure heralded the era of cardiac allotransplantation, another dramatic treatment option for infants with HLHS. Even today, at least 20% of infants on the waiting list for transplantation die while waiting for a transplant, and the short-term posttransplantation survival is 70% to 80%.8 With these dramatic breakthroughs, babies with HLHS may undergo either a modified Norwood procedure, culminating in a Fontan procedure, or a heart transplantation. Nevertheless, when presented with all the pertinent information and survival data, some families still choose compassionate care, with no treatment provided. This approach remains controversial among pediatric cardiologists, pediatric cardiothoracic surgeons, pediatricians, and families. The optimum approach to this defect remains unclear.

Certainly, there have been dramatic advances in the medical/surgical treatment of HLHS over the past several decades; however, follow-up data present a concern. Several studies have demonstrated that these children experience neurodevelopmental problems and major developmental disabilities. Both cognitive deficits and adaptive/behavioral abnormalities have been reported.9

Another area of concern is these children’s ability to perform daily activities and routine exercise. In this issue of The Journal, Jenkins et al10 describe decreased exercise performance in children with HLHS who have undergone either cardiac transplantation or Fontan’s procedure after a Norwood series. Both treatment groups demonstrated decreased exercise performance compared with age-matched controls. This was more dramatic in the group who underwent Fontan’s procedure. There are several possible explanations for this observation. Children who have congenital heart disease of a serious nature often are restricted from engaging in vigorous physical activity, protected by their caregivers, their parents, or their own self-limitations. Studies have suggested that these children can improve their aerobic capacity with physical conditioning when their deconditioning is due to physical inactivity.11 This physical rehabilitation is usually safe when done carefully.

There are other explanations, however. Children who undergo Fontan’s procedure have a single ventricle that does not perform properly with volume loading and has chronotropic restrictions that limit the ability to increase the heart rate during exercise. These limitations likely will not improve with physical conditioning. In addition, children who have undergone serial cardiac operations may have pulmonary issues. Children who undergo Fontan’s procedure have surgery-related reduced vital capacity in addition to a ventilation–perfusion mismatch.12 They may have high pulmonary arterial wedge pressures, causing arterial desaturation with subsequent hypocapnia and resulting in accelerated inefficient ventilation at rest and during exercise.

What Jenkins and coworkers and others have demonstrated is that even though these children may have undergone successful surgical repair of their defects, they are often left with a reduced quality of life. With continued surgical and pharmacologic advances, those caring for these children have an obligation to monitor them and make every attempt to improve their quality of life. This quality of life is not limited to these children’s medical issues, but extends to their ability to perform daily activities and to be successful citizens in school and beyond.

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References 

  1. Fyler DC. Report of the New England Regional Infant Cardiac Program. Pediatrics. 1980;65:376–461
  2. Morris CD, Outcalt J, Menashe VD. Hypoplastic left heart syndrome: natural history in a geographically defined population. Pediatrics. 1990;85:977–983
  3. Norwood WI, Kirklin JK, Sanders SP. Hypoplastic left heart syndrome: experience with palliative surgery. Am J Cardiol. 1980;45:87–91
  4. Norwood WI, Lang P, Hanson DD. Physiologic repair of aortic atresia–hypoplastic left heart syndrome. N Engl J Med. 1983;308:23–26
  5. Jacobs ML, Blackstone EH, Bailey LL The Congenitial Heart Surgeons Society. Intermediate survival in neonates with aortic atresia: a multi-institutional study. J Thorac Cardiovasc Surg. 1998;116:417–431
  6. Tweddell JS, Hoffman GM, Mussatto KA, Fedderly RT, Berger S, Jaquiss RDB, et al. Improved survival of patients undergoing palliation of hypoplastic left heart syndrome: lessons learned from 115 consecutive patients. Circulation. 2002;106:82–89
  7. Bailey LL, Nehlsen-Cannarella SL, Concepcion W, Jolley WB. Baboon-to human cardiac xenotransplantation in a neonate. JAMA. 1985;254:3321–3329
  8. Razzouk AJ, Chinnock RE, Gundry SR, Johnston JK, Larson RL, Baum MF, et al. Transplantation as a primary treatment for hypoplastic left heart syndrome: intermediate-term results. Ann Thorac Surg. 1996;62:1–7
  9. Mahle WT, Clancy R, Moss EM, Jobes D, Wernovsky G. Neurodevelopmental outcome and lifestyle assessment in school-aged and adolescent children with hypoplastic left heart syndrome. Pediatrics. 2000;105:1082–1089
  10. Jenkins PC, Chinnock RE, Jenkins KJ, Mahle WT, Mulla N, Sharkey AM, et al. Decreased exercise performance with age in children with hypoplastic left heart syndrome. 2008;152:507–512
  11. Rhodes J, Curran TJ, Camil L, Rabideau N, Fulton DR, Naomi S, et al. The magnitude and mechanisms by which cardiac rehabilitation improves the exercise function of children with congenital heart disease. Circulation. 2004;110(Suppl III):III-386
  12. Ohuchi H, Ohashi H, Takasugi H, Yamada O, Yagihara T, Echigo S. Restrictive ventilatory impairment and arterial oxygenation characterize rest and exercise ventilation in patients after Fontan’s operation. Pediatr Cardiol. 2004;25:513–521

PII: S0022-3476(07)01066-9

doi:10.1016/j.jpeds.2007.11.010

Refers to article:

  • Decreased Exercise Performance with Age in Children with Hypoplastic Left Heart Syndrome , 19 November 2007

    Pamela C. Jenkins, Richard E. Chinnock, Kathy J. Jenkins, William T. Mahle, Neda Mulla, Angela M. Sharkey, Michael F. Flanagan
    The Journal of Pediatrics April 2008 (Vol. 152, Issue 4, Pages 507-512)

The Journal of Pediatrics
Volume 152, Issue 4 , Pages 456-457, April 2008

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