Venous wave protraction time is shorter in pre-eclampsia than in normal third trimester pregnancy

Abstract

Background: Venous pulse waves, as obtained by Duplex Ultrasonography, are a reflection of cardiac right atrial function. The time-interval between cardiac electrocardiographic (ECG) signals and venous Doppler waves is the so-called Venous Wave Protraction Time (VWPT).

Aim: To compare Hepatic Vein (HV) VWPT between normal third trimester pregnancy and pre-eclampsia (PE).

Methods: Cross-sectional study in 2 groups of 10 women with normal pregnancy or PE at gestation of 28-33 weeks. Three consecutive venous Doppler waves were recorded at the craniocaudal midportion of the liver from each of the three main branches of HV, simultaneously with an ECG. The time-interval between the ECG P-wave and corresponding A-deflection of venous Doppler waves was measured, with correction for PE-induced changing heart rate (PA/RR = VWPT). For both groups, means and SD were calculated and compared statistically using conventional F-tests for linear mixed-effects models (SAS procedure MIXED).

Results: VWPT was significantly shorter in pre-eclampsia than in normal pregnancy [0.25±0.09 versus 0.42±0.14, p=0.0042]. This difference persisted under antihypertensive treatment [n=6; 0.23±0.10, p=0.0066].

Conclusion: VWPT is significantly shorter in PE than in normal pregnancy. This observation probably results from PE-related maternal cardiovascular maladaptation. Our study illustrates that VWPT may be a potential new parameter to study venous hemodynamics during pathological pregnancies, in particular PE.