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2017-05-01  Concomitant PACs and PVCs with umbilical vein varix  ©   www.TheFetus.net

Concomitant PACs and PVCs with umbilical vein varix
 Islam Badr, M.Sc.*; Rasha Kamel, MD*; Ashraf Elbaz, M.Sc**; Sameh Abdel Latif Abdel Salam, MD***;

* Fetal medicine unit, Cairo University, Egypt;

** El Galaa Teaching Hospital; 

***Radiology department, Kasr Alainy hospitals, Cairo University, Egypt;

 


Irregularity in fetal heart rate is attributed in the vast majority of cases to premature contractions 1. Premature contractions can arise either in the atria or ventricles with the former being more common with reported minimal risk of developing supra-ventricular tachycardia in the former and ventricular tachycardia in the latter, thus a follow up is required in both and should be more close in the ventricular type 2. The degree of maturity of premature atrial contraction is the determinant of their conduction to the ventricle or blockage into the atrio-ventricular node 1. The risk of developing tachycardia is higher in cases of multiple atrial ectopic beats that are blocked resulting in decrease in ventricular rate than in cases with normal rate 3.

Umbilical vein varix is diagnosed if there is increase in the diameter of the umbilical vein more than 9 mm or more than 50% of the intrahepatic portion of the vein according to some authors4. However it should be mentioned that there are no clear criteria either for the diagnosis neither for the follow-up 4. The vascular nature of this anomaly renders its diagnosis into a simple process by Doppler techniques 4,5. There is controversy about the significance of this anomaly; several reports have linked it to high risk of adverse outcome while other reports link it to good outcome 4,5.     



Case report

24 year old G2P1 woman referred to Cairo University Fetal Medicine Unit at 39 weeks of gestation due to a concern about an irregularity in fetal heart rhythm noted during auscultation of the fetal heart by CTG. Our ultrasound examination revealed the following:

- Irregular heart rhythm.
- During periods of irregularity of the heart rhythm; the atrial contractions were perfectly regular with premature ventricular contractions noticed on M-mode tracing associated with compensatory pauses during this type of irregularity.
- During other periods of irregularity; there were premature atrial contractions that made the atrial contractions irregular; the vast majority of them were conducted to the ventricles.
- Dilatation of the umbilical vein starting nearly at the level of origin of the inferior branch of the left portal vein (LPVi) and extending to the level of origin of the superior branch of left portal vein (LPVs).
- Color Doppler examination demonstrated filling of the varix with color signal denoting absence of any thrombotic events.

Postnatal follow up of the case confirmed our findings. A 24-hour ambulatory ECG confirmed the presence of premature contractions denoting that the vast majority of them were originating from the ventricles with some originating form the atria. 
M-mode tracing of the heart of the neonate strikingly demonstrated the premature atrial contractions at the time of examination.

Neonatal abdominal ultrasound confirmed the presence of the varix extending from the level of the origin of LPVi to the origin of LPVs exactly as prenatally documented with physiological near total obliteration of the umbilical vein.
One month after delivery (time of reporting this case), there was no adverse outcome and the neonate was doing well with infrequent premature contractions (7% as reported by the 24 hour ambulatory ECG).

To the best of our knowledge, we are unaware of any prenatal report describing the simultaneous occurrence of premature both atrial and ventricular contractions. This finding may suggest that the immaturity of the fetal cardiac conductive system may make it susceptible to an atrial and a ventricular pacemakers simultaneously.  


In all images white arrows point to the atrial contractions with the yellow arrows pointing to the premature atrial contractions. Also the ventricular contractions are demarcated by red arrows with the blue arrows pointing to the premature ventricular contractions. 


Video 1: Four-chamber and LVOT views demonstrating the irregularity in the fetal heart rhythm.





Images 1, 2: M-mode tracing recording the mechanical activity in both the right atrial and left ventricular walls simultaneously demonstrating the perfectly regular atrial contractions and the ventricular extra systoles. Note also the compensatory pause.

 



Image 3: demonstrates M-mode tracing of both the left and right ventricular walls showing the ventricular extra systoles and the compensatory pause.





Images 4, 5: M-mode tracing of both the right atrium and the left ventricle demonstrating simultaneously both the atrial and ventricular extra systoles.

 



Images 6, 7, 8: Pulsed wave tracing of Aorta/SVC, pulmonary artery/pulmonary vein and renal artery/renal vein demonstrating the premature atrial contractions. All of which are conducted to the ventricles.

 



Images 9, 10: Demonstrates the umbilical vein varix. Note that the dilatation starts somewhere around the inferior branch of the left port vein and extend nearly to the origin of the superior branch of the left portal vein. This was what we exactly found in our postnatal images after near total obliteration of the umbilical vein. Image 10 shows the typical venous waveform of the umbilical vein. LPVi: inferior branch of left portal vein, LPVs: superior branch of left portal vein, LPVm: medical branch of left portal vein, DV: ductus venosus.

 



Videos 2 to 9: Gray-scale and color Doppler showing the varix and the clearly depicted relationship to the portal veins branches. The vascular nature of the cyst as shown by Doppler techniques is of a tremendous help in the process of differential diagnosis.

    



Images 11, 12, 13, 14 and Video 10: Four-dimensional color STIC volume demonstrating the umbilico-portal system together with the hepatic system showing the dilatation of the umbilical vein between the inferior and superior branches of the left portal vein. Note also the main portal vein which is the landmark between the left and the right portal vein6. ARPV: anterior branch of right portal vein, PRPV: posterior branch of right portal vein, MPV: main portal vein. 

  



Images 15, 16 and Videos 11, 12: postnatal documentation of the umbilical vein varix showing the same relationship to the portal vein branches as detected prenatally. Filling of the varix by color Doppler confirms the absence of thrombosis.

  



Image 17: M-mode with the M-line passing through the right ventricle and left atrium strikingly documenting a conducted premature atrial contraction.



 
 
References
 

1. Weber R, Stambach D, Jaeggi E. Diagnosis and management of common fetal arrhythmias. Journal of the Saudi Hear Association 2011; 23:61-66.
 
2. Killen SAS, Fish FA. Fetal and neonatal arrhythmias. NeoReviews 2008; 9: e242-e252.
 
3. Simpson JM. Fetal arrhythmias. Ultrasound Obstet Gynecol 2006;27: 599-606.
 
4. Brenner AW, Simchen MJ, Kassif E, Achiron R, Zalel Y. Isolated fetal umbilical vein varix – prenatal sonographic diagnosis and suggested management. Prenat Diagg 2009; 20: 229-233.
 
5. Fung TY, Leung TN, Leung TFung TY, Leung TN, Leung T, Lau TK. Fetal intra-abdominal umbilical vein varix: what is the clinical significance? Ultrasound Obstet Gynecol 2005; 25:149-154. 

6. Yagel S, Kivilevitch Z, Valsky DV, Messing B, Shen O, Achiron R. The fetal venous system, Part I: normal embryology, anatomy, hemodynamics, ulrasound evaluation and Doppler investigation. Ultrasound Obstet Gynecol 2010; 35:741-570
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