Venous Pulse Transit Time in Normal Pregnancy and Preeclampsia

Abstract

Uncomplicated pregnancies (n = 16) were evaluated longitudinally and compared to early- (n = 12) and late-onset (n = 14) preeclampsia patients, assessed once at diagnosis. Pulse transit time (PTT), equivalent to pulse wave velocity, was measured as the time interval between corresponding characteristics of electrocardiography and Doppler waves, corrected for heart rate, at the level of renal interlobar veins, hepatic veins, and arcuate branches of uterine arteries. Impedance cardiography was used to measure PTT at the level of the thoracic aorta. In normal pregnancy, all PTT increased gradually (P ≤ .01). Pulse transit time was shorter in late-onset preeclampsia (P < .05) and also in early-onset preeclampsia, with exception for hepatic veins and thoracic aorta (P > .05). Our results indicate that PTT is an easy and highly accessible measure for vascular reactivity at both arterial and venous sites of the circulation. Our observations correlate well with known gestational cardiovascular adaptation mechanisms. This suggests that PTT could be used as a new parameter in the evaluation and prediction of preeclampsia.

Maternal venous hemodynamics in gestational hypertension and preeclampsia

“…Pulse transit time is considered a measure for vascular tone: in conditions of increased vascular tone or stiffness, the propulsion wave is transported faster through the circulation than in conditions of low vascular tone, and this is responsible for a shorter time interval between ECG and pulse or Doppler wave [28-30]. During PE, shorter pulse transit times have been measured at both the arterial [31] and venous sides of the circulation [15]. We reported an increase of VPTT in UP and a reduction in PE, which correspond with a reduction or increase of venous tone in normal gestation and PE respectively [15].…”

“…After informed consent, all women had ECG-D investigations in supine position at the level of hepatic veins (HV), renal interlobar veins (RIV) of both kidneys, and left and right arcuate uterine arteries as reported [22], using a 3.5 – 5 MHz probe (Toshiba Aplio Mx © , Toshiba Medical Systems nv, Sint-Stevens-Woluwe, Belgium). Uterine arcuate arteries were preferred over uterine arteries for their intra-parenchymatous localization, comparable with the localization of hepatic and renal interlobar veins [15]. The Doppler ultrasound measurements of the uterine arcuate arteries were performed within a maximum of 2 cm distance from the bifurcation at the uterine artery.…”

“…Maternal venous pulse transit times (VPTT) were defined as the time interval (ms) between the maternal ECG P-wave and corresponding Doppler A-wave, corrected for the duration of the corresponding cardiac cycle [14]. Maternal arterial pulse transit time (APTT) was defined as the time interval (ms) between the maternal ECG Q-wave and start of Doppler systole, again corrected for the duration of the corresponding cardiac cycle [15]. …”

“…Combined electrocardiogram - Doppler ultrasonography (ECG-D) [13-15] and impedance cardiography (ICG) are non-invasive methods to study maternal hemodynamics, with acceptable reproducibility and repeatability when applied according to standardized protocols [16-20]. …”

Impedance cardiography: Recent advancements

“…Tomsin et al [26] tried to evaluate pulse transit time (PTT), equivalent to pulse wave velocity, as the time interval between corresponding characteristics of electrocardiography and Doppler waves, corrected for HR, at the level of renal interlobar veins, hepatic veins, and arcuate branches of uterine arteries. They also used ICG to measure PTT at the level of the thoracic aorta.…”