Diagnosis and prognosis of fetal cardiomyopathies: a review

Cardiomyopathies (CM) are a very rare disease in fetuses with a very poor outcome. Only isolated case reports and small case series were reported. According with published studies we will describe the fetal CM starting from their echocardiographic presentation: dilated cardiomyopathy (DCM) with dilatation of either or both ventricles and impaired ventricular function, and hypertrophic cardiomyopathy (HCM) with different degree of disproportionate hypertrophy of the myocardial walls. The term of the "noncompaction" of the left ventricular myocardium, is used in cases with DCM with evidence of numerous prominent trabeculations with deep myocardial recesses. In series of neonates and infant the CM occur in about 2-7%, but probably during the fetal life the prevalence is higher: 6% - 11%. The high intrauterine loss, occurring in one third of affected fetuses, likely accounts for these differences. Fetal echocardiography, B and M-mode, is the main diagnostic tool and it is useful for the therapeutic orientation and to determine the neonatal outcome. A haemodynamic evaluation can be performed by Doppler mode. Systolic and diastolic fetal cardiac function have become part of the routine evaluation of the fetal heart. Cardiomyopathies can be isolated or associated with other cardiac and non cardiac malformations. All the studies confirm a great variability of DCM in the fetal age as for the anatomical and functional forms, etiology and hemodynamic impact with different final outcome. Genetic, metabolic, infective, and cardiac diseases may present with DCM. Ventricular dysfunction may be progressive in utero and after birth, but possibility of improvement or even normalization of the left ventricular dysfunction is known in all forms of DCM, "idiopathic", post infective or in noncompaction of left ventricle. The outcome is worse in presence of fetal hydrops, significant atrioventricular valve regurgitation, for the earlier age at presentation and when diastolic dysfunction is associated with systolic dysfunction. Etiologically primary fetal HCM is a heterogeneous condition that can be the result of intrinsic fetal pathology as well as of extrinsic factors. It can be concentric or asymmetric. Prognosis of infants with HCM associated with maternal diabetes is good while a bad prognosis has been reported in fetuses without diabetic mother. HCM may be evolutive, mainly after birth; otherwise there are also cases that improve or regress completely. Unfortunately, a poor outcome is observed in most, particularly in DCM, with only a few therapeutic options available. Detailed evaluation of fetal and maternal condition provide prognostic information for prenatal counselling and may lead to improved outcome of at least some affected pregnancies.