A Study on Fetal Intracardiac Echogenic Foci: Pondering Possible Etiology of Echogenicity with Histopathology Correlation

Objective: The objective of this study is to determine the frequency, location, and delineation of the echogenicity of intracardiac echogenic foci (ICEF) and to ponder the possible etiology of ICEF. Materials and Methods: Retrospective study of 2445 referred cases in second and third trimester for fetal cardiac ultrasound scan from 2010 to 2020, targeted for ruling out congenital heart disease were evaluated and analyzed in detail for ICEF. Further postnatal follow-up was done in 64 cases of ICEF till 7 years of age to see the natural course. Histopathology was performed from one case of fetal autopsy at 19 weeks of gestation for further correlation. Results: Among the fetal cardiac ultrasound cases, 323 (13.2%) showed ICEF (95% confidence interval 11.9–14.6). Majority of these ICEF (96%) were in the left ventricular cavity, and then both ventricles (3%) and remaining in right ventricle and all were located within the papillary muscles. On follow-up of 66 postnatal cases, ICEF had resolved in 97% by 5 years of age. Only two cases reported to have congenital heart disease. No chromosomal anomalies was associated in any case. Histopathology of fetal heart specimen in one case revealed myxomatous degeneration at the apices of the papillary muscle. Conclusion: Frequency of single ICEF is much higher in the left ventricle, and it is invariably located within the upper third of the anterior papillary muscle in such cases. As the gestational age advances, ICEF can resolve in utero, and further complete resolution is seen by 1–7 years of postnatal life. Variability in the echogenicity could be part of transformation of myxomatous tissues to fibrosis or microcalcification. In this study, ICEF have no particular association with congenital heart disease or chromosomal association.