Normal Lower Limb Venous Doppler Flow Phasicity: Is It Cardiac or Respiratory?

Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City 52242, USA.
American Journal of Roentgenology (Impact Factor: 2.73). 01/1998; 169(6):1721-5. DOI: 10.2214/ajr.169.6.9393197
Source: PubMed


The purposes of this study were to determine the origin and nature of normal lower limb venous Doppler flow phasicity and to assess normal and respiratory variations.
The common femoral veins of 12 healthy volunteers (three men and nine women; age range, 21-50 years; mean, 29 years) were evaluated by detailed spectral Doppler examinations with simultaneous ECG and respirometric tracings. The examinations were performed using a 5- or 7-MHz linear-array transducer with breath held in mid respiration, at the end of deep expiration, at the end of deep inspiration, during Valsalva's maneuver, and during quiet and deep breathing. The tracing obtained during breath-hold in mid respiration was considered the baseline. Tracings obtained during the other respiratory phases were analyzed for changes from the baseline. Doppler tracings were analyzed for phasicity, waveform frequency, components, velocities, velocity ratios, and presence of retrograde flow, all in correlation with simultaneous ECG and respirometric tracings. Tracings were analyzed independently by two observers to assess interobserver variability.
With breath-hold in mid respiration, the common femoral vein Doppler tracings consisted of multiphasic waveforms that had a frequency similar to that of the heart rate. Each waveform consisted of systolic, v, diastolic, and a waves. The systolic wave occurred 0.4 sec later than the QRS complex of the ECG and was always antegrade. The v wave was always retrograde without flow reversal. The diastolic wave was always antegrade. The a wave was always retrograde but showed flow reversal in nine of 12 subjects. The systolic:diastolic velocity ratio ranged from 0.9 to 1.5 (mean, 1.1). The minimum:maximum velocity ratio ranged from -0.4 to 0.2 (mean, -0.15). With breath-hold at the end of expiration, the waveforms became slightly damped, becoming biphasic in five subjects and remaining multiphasic in seven. With breath-hold at the end of inspiration, the waveforms became nonphasic or biphasic in nine and decreased in velocity in 12. With Valsalva's maneuver, flow stopped. With normal respiration, cardiac waveforms were modulated by higher amplitude and less frequent biphasic respiratory waves. The plasticity was equal in two, dominantly cardiac in six, and dominantly respiratory in four. Flow velocity increased with expiration and decreased with inspiration. With deep breathing, the respiratory waves further increased, while the cardiac ones decreased in amplitude. The latter continued to modulate the respiratory phasicity in 10 subjects.
During quiet respiration, lower limb venous Doppler tracings consisted of both cardiac and respiratory waveforms. Although respiratory waveforms disappeared when patients held their breath, Doppler tracings continued to be multiphasic and cardiac. Therefore, cardiac phasicity in lower limb venous Doppler tracings does not necessarily indicate cardiac disease. Other respiratory phases can modulate this basic cardiac pattern. Decrease in or loss of phasicity in these waveforms does not always mean proximal obstruction, because it can be caused by respiratory factors. Finally, the presence of minimal cyclic retrograde flow that is 5 cm/sec or less does not necessarily indicate cardiac disease.

1 Follower
617 Reads
  • Source
    • "Deep thoracic breathing in inspiration produces rapid acceleration of blood flow in veins located near the thorax, such as the hepatic vein, jugular vein, and inferior vena cava [51], while the blood velocity in these veins is reduced just as rapidly at the start of expiration [52]. Mechanical ventilation causing a higher positive end-expiratory pressure-induced increase in lung volume could impede venous return, thereby altering systemic hemodynamics and hepatic venous outflow [53]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Non-invasive measurement of splanchnic hemodynamics has been utilized in the clinical setting for diagnosis of gastro-intestinal disease, and for determining reserve blood flow (BF) distribution. However, previous studies that measured BF in a "single vessel with small size volume", such as the superior mesenteric and coeliac arteries, were concerned solely with the target organ in the gastrointestinal area, and therefore evaluation of alterations in these single arterial BFs under various states was sometimes limited to "small blood volumes", even though there was a relatively large change in flow. BF in the lower abdomen (BF(Ab)) is potentially a useful indicator of the influence of comprehensive BF redistribution in cardiovascular and hepato-gastrointestinal disease, in the postprandial period, and in relation to physical exercise. BF(Ab) can be determined theoretically using Doppler ultrasound by subtracting BF in the bilateral proximal femoral arteries (FAs) from BF in the upper abdominal aorta (Ao) above the coeliac trunk. Prior to acceptance of this method of determining a true BF(Ab) value, it is necessary to obtain validated normal physiological data that represent the hemodynamic relationship between the three arteries. In determining BF(Ab), relative reliability was acceptably high (range in intra-class correlation coefficient: 0.85-0.97) for three arterial hemodynamic parameters (blood velocity, vessel diameter, and BF) in three repeated measurements obtained over three different days. Bland-Altman analysis of the three repeated measurements revealed that day-to-day physiological variation (potentially including measurement error) was within the acceptable minimum range (95% of confidence interval), calculated as the difference in hemodynamics between two measurements. Mean BF (ml/min) was 2951 ± 767 in Ao, 316 ± 97 in left FA, 313 ± 83 in right FA, and 2323 ± 703 in BF(Ab), which is in agreement with a previous study that measured the sum of BF in the major part of the coeliac, mesenteric, and renal arteries. This review presents the methodological concept that underlies BF(Ab), and aspects of its day-to-day relative reliability in terms of the hemodynamics of the three target arteries, relationship with body surface area, respiratory effects, and potential clinical usefulness and application, in relation to data previously reported in original dedicated research.
    Cardiovascular Ultrasound 03/2012; 10(1):13. DOI:10.1186/1476-7120-10-13 · 1.34 Impact Factor
  • Source
    • "Of most direct interest is the study reported by Raju S et al [21], who describe flow conditions under ambulatory conditions but not under first application of the gravity field, whilst Neglen and Raju [22] also focus on the measurement of ambulatory pressures in individuals with signs of chronic venous deficiency. Willeput R et al [23] and Abu-Yousef M [24] focus on rest and respiratory conditions. Again, it is suggested that the frequencies associated with these temporal variations are relatively low compared with those associated with the phenomenon addressed in this paper. "
    [Show abstract] [Hide abstract]
    ABSTRACT: It is widely accepted that venous valves play an important role in reducing the pressure applied to the veins under dynamic load conditions, such as the act of standing up. This understanding is, however, qualitative and not quantitative. The purpose of this paper is to quantify the pressure shielding effect and its variation with a number of system parameters. A one-dimensional mathematical model of a collapsible tube, with the facility to introduce valves at any position, was used. The model has been exercised to compute transient pressure and flow distributions along the vein under the action of an imposed gravity field (standing up). A quantitative evaluation of the effect of a valve, or valves, on the shielding of the vein from peak transient pressure effects was undertaken. The model used reported that a valve decreased the dynamic pressures applied to a vein when gravity is applied by a considerable amount. The model has the potential to increase understanding of dynamic physical effects in venous physiology, and ultimately might be used as part of an interventional planning tool.
    BioMedical Engineering OnLine 02/2008; 7(1):8. DOI:10.1186/1475-925X-7-8 · 1.43 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The current commercially available sequential intermittent pneumatic compression device used for the prevention of deep venous thrombosis has a constant cycle of 11 seconds' compression and 60 seconds' deflation. This deflation period ensures that the veins are filled before the subsequent cycle begins. It has been suggested that in some positions (eg, semirecumbent or sitting) and with different patients (eg, those with venous reflux), refilling of the veins may occur much earlier than 60 seconds, and thus a more frequent cycle may be more effective in expelling blood proximally. The aim of the study was to test the effectiveness of a new sequential compression system (the SCD Response Compression System), which has the ability to detect the change in the venous volume and to respond by initiating the subsequent cycle when the veins are substantially full. In an open controlled trial at an academic vascular laboratory, the SCD Response Compression System was tested against the existing SCD Sequel Compression System in 12 healthy volunteers who were in supine, semirecumbent, and sitting positions. The refilling time sensed by the device was compared with that determined from recordings of femoral vein flow velocity by the use of duplex ultrasound scan. The total volume of blood expelled per hour during compression was compared with that produced by the existing SCD system in the same volunteers and positions. The refilling time determined automatically by the SCD Response Compression System varied from 24 to 60 seconds in the subjects tested, demonstrating individual patient variation. The refilling time (mean +/- SD) in the sitting position was 40.6 +/- 10. 0 seconds, which was significantly longer (P <.001) than that measured in the supine and semirecumbent positions, 33.8 +/- 4.1 and 35.6 +/- 4.9 seconds, respectively. There was a linear relationship between the duplex scan-derived refill time (mean of 6 readings per leg) and the SCD Response device-derived refill time (r = 0.85, P <. 001). The total volume of blood (mean +/- SD) expelled per hour by the existing SCD Sequel device in the supine, semirecumbent, and sitting positions was 2.23 +/- 0.90 L/h, 2.47 +/- 0.86 L/h, and 3.28 +/- 1.24 L/h, respectively. The SCD Response device increased the volume expelled to 3.92 +/- 1.60 L/h or a 76% increase (P =.001) in the supine position, to 3.93 +/- 1.55 L/h or a 59% increase (P =. 001) in the semirecumbent position, and to 3.97 +/- 1.42 L/h or a 21% increase (P =.026) in the sitting position. By achieving more appropriately timed compression cycles over time, the new SCD Response System is effective in preventing venous stasis by means of a new method that improves on the clinically documented effectiveness of the existing SCD system. Further studies testing its potential for improved efficacy in preventing deep venous thrombosis are justified.
    Journal of Vascular Surgery 12/2000; 32(5):932-40. DOI:10.1067/mva.2000.110358 · 3.02 Impact Factor
Show more


617 Reads
Available from