Familial fatal fetal cardiomyopathy with isolated myocardial calcifications: a new syndrome?

Massive myocardial calcification in second-trimester fetuses: antenatal detection and causes

Massive myocardial calcifications were detected by antenatal ultrasound examination in four second-trimester fetuses. In one fetus, multiple cardiac rhabdomyomas were the initial diagnosis. One fetus presented with arthrogryposis and the brain and spinal cord showed severe hypoxic-ischemic damage. One fetus was hydropic and had severe cardiac malformations. The fourth fetus had congenital heart block and maternal serum was positive for anti-Ro and anti-La antibodies. Myocardial calcifications in the first three fetuses were most likely to be caused by hypoxic-ischemic damage to the heart, and immunological mechanisms were responsible in the other fetus. Antenatally detected myocardial echogenic foci in a fetus leading to a termination of pregnancy or associated with fetal death should be investigated with a full postmortem examination. It is important to confirm the presence of calcifications as distinct from a rhabdomyoma as genetic counseling is completely different. The demonstration of associated lesions in other organs also helps to explain the pathogenesis underlying this condition.

Clinical implications of the prenatal sonographic finding of fetal myocardial echogenic foci

OBJECTIVE

The purpose of this study was to investigate the clinical implications of fetal echogenic foci limited to the myocardium of the ventricular wall (EMF) or intraventricular septum detected during prenatal sonography.

METHODS

A retrospective review of fetuses found to have EMF during prenatal sonography from April 1990 through December 2003 was undertaken. Videotapes and reports were reviewed to determine the indication for sonography, gestational age, location, sonographic characteristics of the masses, and additional fetal findings. Sources of outcome data included neonatal and pediatric records and echocardiographic reports.

RESULTS

Five fetuses were identified. Indications for sonographic evaluation included fetal growth (n = 4) and follow-up twin-twin transfusion syndrome (n = 1). Mean gestational age +/- SD at diagnosis was 23.7 +/- 8.0 weeks (range, 17.1-36.4 weeks). The EMF identified were within the right ventricular myocardium (n = 2), intraventricular septum (n = 1), left ventricular myocardium (n = 1), and myocardium of the cardiac apex (n = 1). All foci appeared sonographically "bright as bone." The foci ranged in size from 0.1 x 0.1 to 1.2 x 0.9 cm. Neonatal echocardiographic findings were reported as normal for each of the cases. Follow-up examinations available for up to 2.5 years of age showed normal cardiac function.

CONCLUSIONS

The prenatal identification of EMF is unlikely to lead to notable short-term pathologic conditions because the fetuses in this investigation had unremarkable neonatal and pediatric echocardiograms and normal cardiac function.

Ventricular septal defect and cardiomyopathy in mice lacking the transcription factor CHF1/Hey2

Ventricular septal defects are common in human infants, but the genetic programs that control ventricular septation are poorly understood. Here we report that mice with a targeted disruption of the cardiovascular basic helix-loop-helix factor (CHF)1Hey2 gene show isolated ventricular septal defects. These defects result primarily in failure to thrive. Mice often succumbed within the first 3 wk after birth and showed pulmonary and liver congestion. The penetrance of this phenotype varied, depending on genetic background, suggesting the presence of modifier genes. Expression patterns of other cardiac-specific genes were not affected. Of the few animals on a mixed genetic background that survived to adulthood, most developed a cardiomyopathy but did not have ventricular septal defects. Our results indicate that CHF1 plays an important role in regulation of ventricular septation in mammalian heart development and is important for normal myocardial contractility. These mice provide a useful model for the study of the ontogeny and natural history of ventricular septal defects and cardiomyopathy.