(Ultrasound Review) An isolated echogenic heart focus is not an indication for amniocentesis, according to sonologists at the Woman’s Health Alliance in Nashville.
In a prospective analysis of unselected second-trimester pregnancies, Dr. Claudio Coco and colleagues established the occurrence of echogenic heart focus, and its association with chromosomal anomalies.
According to the authors, mineralization within the papillary muscle has no histopathologic significance and postnatal persistence does not effect heart function. However, this finding has a known association with trisomy 21; therefore, its presence increases the risk for aneuploidy.
Published in the Journal of Ultrasound in Medicine, the study discovered 479 cases of heart echogenic focus in 12,672 fetuses. They reported that "90.4% were isolated, whereas 9.6% had associated findings. Eleven patients had fetuses with trisomy 21 (9/10,000). Eight of those did not have an echogenic focus, whereas three had a heart echogenic focus. Only 1 fetus with trisomy 21 had an isolated echogenic focus."
Comparing the total cases of echogenic heart focus and trisomy 21 with isolated echogenic heart focus, the positive likelihood ratios were 7.25 and 2.66. Although the authors demonstrated an increased risk of aneuploidy in fetuses with heart echogenic focus, they recommended a detailed morphologic survey with ultrasound imaging, and correlation with established maternal risk.
"Amniocentesis need not be offered to patients who are otherwise at low risk and have an isolated echogenic intracardiac focus," they recommended.
"Our study indicates that the presence of another major or minor sign with a heart echogenic focus justifies the performance of amniocentesis," they wrote. The accepted miscarriage rate associated with amniocentesis is 1/200. The number of fetal miscarriages would have been 2.16 if all women with fetuses showing an echogenic focus of the heart had undergone amniocentesis.
Restricting amniocentesis to those with associated findings and a heart echogenic focus indicated amniocentesis in only 46 patients, thereby reducing the potential fetal loss to 0.23 fetuses. Of the 46 patients who had karyotyping performed, two cases of trisomy 21 were identified.
An isolated echogenic heart focus is not an indication for amniocentesis in 12,672 unselected patientsClaudio Coco, et. al.
Department of ultrasound, Woman’s Health Alliance, Nashville.
J Ultrasound Med 2004 April; 23:489-496
By Ultrasound Review
May 28, 2004
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