Fetal cardiomyopathies pathogenic mechanisms, hemodynamic findings, and clinical outcome

Background—Although the prenatal diagnosis of most fetal structural heart defects and dysrhythmias has been described,there is a paucity of information about cardiomyopathies (CMs) in prenatal life.Methods and Results—-To determine the pathogenic mechanisms, hemodynamic findings, and outcome of fetal CM, wereviewed the fetal echocardiograms and perinatal histories of 55 affected fetuses. Dilated CM was diagnosed in 22 cases,including 2 with congenital infections, 5 familial cases, 6 with endocardial fibroelastosis related to maternal anti-Ro/Laantibodies, and 9 idiopathic cases. Thirty-three had hypertrophic CM, 7 associated with maternal diabetes, 2 withNoonan’s syndrome, 2 with -thalassemia, 18 with twin-twin transfusion syndrome, 1 with familial hypertrophy, and3 with idiopathic hypertrophy. Systolic dysfunction was present in all cases of dilated CM and 15 cases of hypertrophicCM. Diastolic dysfunction was present in 19 of 30 fetuses with assessment of diastolic function parameters. Significantmitral or tricuspid valve regurgitation was seen in 32 cases. Eight fetuses were hydropic and 23 had signs of earlyhydrops. Seven pregnancies were terminated. Of 46 continued pregnancies with follow-up, 29 (63%) died perinatally.The presence of systolic dysfunction, diastolic dysfunction, and significant atrioventricular valve regurgitation wereidentified as risk factors for mortality. By multiple logistic regression, diastolic dysfunction was associated with an8-fold increased risk relative to the other parameters.Conclusions—Fetal CM has a broad spectrum of intrinsic and extrinsic causes. A poor outcome is observed in manyaffected fetuses. Diastolic dysfunction in fetal CM is associated with the highest risk of mortality.