Fetal Cardiac Dysfunction Related to Extracardiac Conditions

The main function of the heart is to provide an adequate perfusion to the different organs. This function is achieved through an adequate filling of the ventricles from the atria (diastole) and the subsequent contraction of the muscular walls in order to generate a sufficient pressure to eject blood from the ventricles into the aorta and pulmonary artery (systole). The inability of the heart to provide sufficient perfusion the body tissues is defined as “heart failure”. In the fetus, heart failure is usually a late event characterized by cardiomegaly, atrioventricular regurgitation and fetal hydrops that occur after a subclinical period of cardiac dysfunction when the heart tries to adapt to the initial stages of an insult through cardiac remodelling. Different cardiac and extra-cardiac conditions can lead to fetal cardiac dysfunction and cardiac failure in utero. Intrinsic cardiac conditions potentially leading to heart failures include cardiomyopathies, structural abnormalities and persistent arrhythmias, while extrinsic causes comprise extra-cardiac lesions that contribute to heart failure through high output states, increased afterload, or cardiac compression resulting in low cardiac output and increased central venous pressures. The aim of this chapter is to provide an up-to-date on the causes, physiopathology, prenatal diagnosis and clinical implications of the most common extra-cardiac conditions potentially leading to fetal heart dysfunction.

Keywords: Congenital anomalies, Diagnosis/methods, Echocardiography, Fetus, Heart failure, Treatment outcome.