Chapters authored
Hypoplastic Left Heart Syndrome
Hypoplastic left heart syndrome (HLHS) is a complex congenital heart disease (CHD) involving hypoplasia of the left ventricle (LV), aorta (Ao), and mitral valve. HLHS was uniformly fatal in the past, now survivable with 3-stage surgical palliation. However, there is high morbidity and mortality, with 25% of HLHS patients either dying or having a heart transplant within 1 year of age. The causes for such high morbidity and mortality are not well understood, but the majority of deaths are directly or indirectly related to cardiovascular/hemodynamics causes. Studies in a mouse model of HLHS uncover important contributing factors for single-ventricle patients such as the patient’s intrinsic factors related to mitochondrial dysfunction, and derangements in the early stages of embryonic development. The HLHS mutant mice were noted to have metabolic dysfunction accompanied by cell cycle arrest and cardiomyocyte differentiation defects. Intrinsic cell defects may contribute to cardiac failure in the HLHS population. Moreover, strong evidence of the genetic etiology of HLHS has come from the observation that HLHS has a high recurrence risk and is associated with various chromosomal abnormalities. In this chapter, we will review the basic pathophysiology, pertinent pre-and post-operative managements of HLHS and recent advances derived from the HLHS mouse model.
Part of the book: Congenital Heart Defects
Ebstein’s Anomaly
Ebstein’s anomaly of the tricuspid valve is a cardiac malformation characterized by downward displacement of the septal and inferior tricuspid valve (TV) leaflets, redundant anterior leaflets with a sail-like morphology, dilation of the true right atrioventricular annulus, TV regurgitation, and dilation of the right atrium and ventricle. The wide variety of anatomic and pathophysiologic presentations of Ebstein’s anomaly has made it difficult to achieve uniform results with surgical repair, resulting in the development of many different surgical techniques for its repair. In 1993, Da Silva et al. developed a surgical technique involving cone reconstruction of the TV. This operation aims to undo most of the anatomic TV defects that occurred during embryologic development and to create a cone-like structure from all available leaflet tissue. The result mimics normal TV anatomy, which is an improvement compared to previously described procedures that result in a monocusp valve coaptation with the ventricular septum. In this chapter, we review the surgical maneuvers that we have used to obtain the best functional TV in cases with several anatomic variations of Ebstein’s anomaly. The cone procedure for reconstruction for Ebstein’s anomaly can be performed with low mortality and morbidity. This tricuspid valve repair is effective and durable for the majority of patients.
Part of the book: Congenital Heart Defects