Left-to-Right Shunts

Abstract

Contrary to the opinion of French pediatrician Henri-Louis1 that isolated ventricular septal defects (VSDs) are universally well tolerated, the subsequent discoveries of Eisenmenger,2 Abbott,3 Wood,4 and others have taught us that the prognosis of left-to-right shunt lesions is not always benign. After more than a century of research, as pediatric cardiologists and congenital heart surgeons, we claim that we know what happens in the lungs and the hearts of these patients and when these changes occur. The repair of VSDs has become routine since Lillehei’s, Warden’s, and Kirklin’s5,6 pioneering work in the 1950s, and we feel that we know in whom, at what age, and for which signs and symptoms to intervene. In reality, significant heterogeneity prevails between different centers and among individual physicians with regard to whether and when to close an isolated moderately restrictive VSD or patent arterial duct. Conceptually, we agree to occlude left-to-right shunts for one or both of the 2 reasons: to treat heart failure and to prevent irreversible pulmonary vascular damage, both of which have been identified as important risk factors in congenital heart disease. The study by Pereda et al7 from Madrid and Barcelona, published in this issue of Circulation: Cardiovascular Imaging , leads us to consider the fate of the myocardium as well. When counseling parents, we point out the low operative mortality and excellent long-term prognosis after successful VSD or patent arterial duct closure. Indeed, postoperative pulmonary hypertensive crises and more than transient and mild ventricular dysfunction are rare occurrences after shunt repair in infancy in the current era. Nonetheless, most of us vividly remember the stormy early postoperative course in the occasional …