ECHOGENIC INTRACARDIAC FOCI

- “GOLFBALLS”

 

Echogenic intracardiac foci are normally described as discrete areas of echogenicity comparable with bone in the region of the papillary muscle in either cardiac ventricle (12). Echogenic intracardiac foci are thought to represent calcifications within the fetal papillary muscle, and may be the result of an aggregate of chordal tissues that have failed to fenestrate completely, enhancement of abnormal tissue, or a collection of fibrous tissue with increased echogenicity (13,14). In some cases, EIF may also represent true microcalcifications within the cardiac muscle (12).

 

Appearing sonographically as a bright spot in one of the ventricles, EIF is a common finding seen in approximately 4% of obstetric sonograms (15). The incidence of EIF can vary with ethnicity, with the lowest rates seen in black populations and the highest rates seen among Asian patients (16). EIF can be single or multiple, and although they can appear in either ventricle, most (72% to 88%) are seen in the left ventricle(14-18). Unlike the diagnosis of echogenic bowel, which can be quite subjective, the diagnosis of EIF is relatively straightforward, although it has been suggested that technical factors, such as the experience of the sonographer, fetal position, and machine settings, may influence visualization of EIF (21).

Reported frequency of 3.5% (1) to 20% (2) of fetuses during routine antenatal scans.

There is an increased frequency in Asian patients  - 30.4% (3)
 

ULTRASOUND

 

Link to Ultrasound

 

EMBRYOLOGY / ETIOLOGY

The papillary muscles originate as a result of the excavation of the ventricular wall, and the chordae tendinae develop as processes of endocardiac tissue fenestrates into thin filaments. If the fenestration process is partial and incomplete, the remaining aggregate of the chordae can be visualized as an echogenic focus (2). The larger size of the left ventricular papillary muscle with larger masses of chordae tissue probably results in echogenic foci being more commonly seen in this area (4).

The results of two pathologocal studies (10,11) leave little doubt that the echogenic foci seen antenatally represent calcifications within the papillary muscles. The reason for both the histological changes and the apparent resolution with advancing gestation are unknown but may be due to abnormal development of the microvasculature involving terminal branches of the coronary artery resulting in ischemic changes in the papillary muscles.
There is widespread consensus that they are of no hemodynamic or other functional significance but their importance, as a possible marker of chromosomal abnormality, remains controversial.

PUBLISHED SERIES

 

Link to Table Of Published Studies

 

ASSOCIATIONS
  • Isolated and benign with a normal karyotype. Although the vast majority of fetuses were normal, the risk of karyotypic abnormality is 1% (6).
  • Associated with Chromosomal Aneuploidy (most of these fetuses had other associated anomalies). Recently numerous groups of workers (7,8) have suggested that the presence of an intracardiac focus should be incorporated into the sonographic scoring index for identifying fetuses at risk for autosomal trisomies. Calcification of the papillary muscle is associated with trisomy 13 and 21.

 

DIFFERENTIAL DIAGNOSIS
  • Intracardiac tumors
    (rhabdomyomas, teratomas, fibromas, hemangiomas).
  • Ventricular thrombi
    (thrombi adherent to the papillary muscles in the left ventricle presenting as a "calcified" posterior papillary muscle on an echo have been reported) (10).
  • Dystrophic valves.
  • Air in the chambers from fetal demise.
  • Endocardial fibroelastosis (multiple and along the endocardial surface.
  • Idiopathic infantile arterial calcification.
  • Viral infections or metabolic disorders.

 

 

REFERENCES
  1. Schechter AG, Fakhry J, Shapiro LR. In utero thickening of the chordae tendinae. A cause of an intracardiac echogenic foci. J Ultrasound Med 1987;6:691-695.
  2. Levy DW, Mintz MC. The left ventricular echogenic focus: a normal finding. Am J Roentgenol 1988;150:85-86.
  3. Shipp TD, Bromley B, Lieberman E et.al. The frequency of the detection of fetal echogenic Intracardiac foci with respect to maternal race. Ultrasound Obstet Gynecol 2000;15:460462
  4. Petrikovsky BM, Challenger M, Wyse LJ. Natural history of echogenic foci within ventricles of the heart. Ultrasound Obstet Gynecol 1995;5:92-94.
  5. How HY, Villafane J, Parihus RR et.al. Small hyperechoic foci of the fetal cardiac ventricle: a benign sonographic finding? Ultrasound Obstet Gynecol 1994;4:205-207.
  6. Simpson, JM, Cook A, Sharland G. The significance of echogenic foci in the fetal heart: a prospective study of 228 cases. Ultrasound Obstet Gynecol 1996; :225-228.
  7. Benacerraf BR, Nadel A, Bromley B. Identification of second trimester fetuses with autosomal trisomy by use of a sonographic scoring index. Radiology 1994;193:135.
  8. Bettelheim D, Deutinger J, Bernaschek G. The value of echogenic foci (golfballs) in the fetal heart as a marker of chromosomal abnormalities. Ultrasound Obstet Gynecol 1999;14:98-100.
  9. Berger I, Levine OR, Antillon J. Echocardiographic diagnosis of a pseudotumor of the left ventricle: a calcified posterior papillary muscle. J Med Soc New Jersey 1979;11:758-760.
  10. Roberts DJ, Genest D. Cardiac histologic pathology characteristic of trisomies 13 and 21. Hum Pathol 1992;23:1130-1140
  11. Brown DL, Roberts DJ, Miller WA. Left ventricular echogenic focus in the fetal heart: pathologic correlation. J Ultrasound Med 1994;13:613-616.
  12. Stone JL, Eddleman KA, Berkowitz RL. The echogenic intracardiac focus. Contemporary Ob/Gyn 1998;43:73-8.  
  13. Roberts DJ, Genest D. Cardiac histologic pathology characteristic of trisomies 13 and 21. Hum Pathol 1992;23:1130-40.  
  14. Bronshtein M, Jakobi P, Ofir C. Multiple fetal intracardiac echogenic foci: not always a benign sonographic finding. Prenat Diagn 1996;16:131-5.  
  15. Sotiriadis A, Makrydimas G, Ioannidis PA. Diagnostic performance of intracardiac echogenic foci for Down syndrome: a meta-analysis. Obstet Gynecol 2003;101:1009-16.  
  16. Shipp TD, Bromley B, Lieberman E, Benacerraf BR. The frequency of the detection of fetal echogenic intracardiac foci with respect to maternal race. Ultrasound Obstet Gynecol 2000;15:460-2.  
  17. Wax JR, Royer D, Mather J, Chen C, Aponte-Garcia A, Steinfeld JD, et al. A preliminary study of sonographic grading of fetal intracardiac echogenic foci: feasibility, reliability and association with aneuploidy. Ultrasound Obstet Gynecol 2000;16:123-7.  
  18. Wax JR, Donnelly J, Carpenter M, Chard R, Pinette MG, Blackstone J, et al. Childhood cardiac function after prenatal diagnosis of intracardiac echogenic foci. J Ultrasound Med 2003;22:783-7.  
  19. Dildy GA, Judd VE, Clark SL. Prospective evaluation of the antenatal incidence and postnatal significance of the fetal echogenic cardiac focus: a case-control study. Am J Obstet Gynecol 1996;175:1008-12.  
  20. Bromley B, Lieberman E, Shipp TD, Richardson M, Benacerraf BR. Significance of an echogenic intracardiac focus in fetuses at high and low risk for aneuploidy. J Ultrasound Med 1998;17:127-31.  
  21. Levine D, Mehta TS, Min KK, Hulka CA, McArdle CR. Technical factors influencing sonographic visualization of fetal echogenic intracardiac foci. J Clin Ultrasound 2000;28:479-84