Performance of Fetal Medicine Foundation algorithm for first trimester preeclampsia screening in an indigenous south Asian population.

BACKGROUND: To evaluate the performance of the Fetal Medicine Foundation (FMF) preterm preeclampsia (PE) screening algorithm in an indigenous South Asian population. METHODS: This was a prospective observational cohort study conducted in a tertiary maternal fetal unit in Delhi, India over 2 years. The study population comprised of 1863 women carrying a singleton pregnancy and of South Asian ethnicity who were screened for preterm pre-eclampsia (PE) between 11 and 14 weeks of gestation using Mean Arterial Pressure (MAP), transvaginal Mean Uterine Artery Pulsatility Index (UtAPI) and biochemical markers - Pregnancy Associated Plasma Protein-A (PAPP-A) and Placental Growth Factor.. Absolutemeasurements of noted biomarkers were converted to multiples of the expected gestational median (MoMS) which were then used to estimate risk for preterm PE < 37 weeks using Astraia software. Women with preterm PE risk of ≥1:100 was classified as as high risk. Detection rates (DR) at 10% false positive rate were calculated after adjusting for prophylactic aspirin use (either 75 or 150 mg). RESULTS: The incidence of PE and preterm PE were 3.17% (59/1863) and 1.34% (25/1863) respectively. PAPP-A and PlGF MoM distribution medians were 0.86 and 0.87 MoM and significantly deviated from 1 MoM. 431 (23.1%) women had a risk of ≥1:100, 75 (17.8%) of who received aspirin. Unadjusted DR using ≥1:100 threshold was 76%.Estimated DRs for a fixed 10% FPR ranged from 52.5 to 80% depending on biomarker combination after recentering MoMs and adjusting for aspirin use. CONCLUSION: The FMF algorithm whilst performing satisfactorily could still be further improved to ensure that biophysical and biochemical markers are correctly adjusted for indigenous South Asian women.

Changes in Vertebral Artery Hemodynamics Associated With McKenzie Therapeutic Cervical Movements: An Exploration Using Duplex Ultrasound Imaging.

OBJECTIVE: The purpose of this study was to explore vertebral artery hemodynamic changes associated with McKenzie therapeutic cervical movements in healthy individuals. METHODS: A single-group repeated-measure design was used to examine 20 healthy participants aged 22.05 (1.69) years, mean (standard deviation). Vertebral artery volume flow, diameter, resistive index, time-averaged maximum velocity, and pulsatility index were measured using Duplex ultrasound. Vertebral artery hemodynamics were measured at cervical neutral positions then compared against vertebral artery hemodynamics measured during end-range loading and after repeated McKenzie therapeutic movements. Wilcoxon signed rank tests were used for comparisons, and standardized mean differences (SMDs) were calculated to quantify the changes in size. RESULTS: Repeated retraction with extension in a sitting position and end-range retraction with extension in supine position were significantly associated with an increase in vertebral artery volume flow, P ≤ .01, and the SMD suggests small-medium changes in size. Statistical significant vertebral artery dilation was observed in the sitting position with protraction, combined retraction with extension, and flexion, P ≤ .01, yet the SMD suggested small changes in size. End-range flexion was significantly associated with a reduction in vertebral artery pulsatility index, and the SMD suggested large changes in size. Repeated retraction with extension in supine position was significantly associated with an increase in vertebral artery time-averaged maximum velocity, yet the SMD revealed no clinically important difference. CONCLUSION: For the healthy participants in this study, McKenzie cervical movements were mostly associated with an increase in vertebral artery hemodynamics.

Bubble size on detachment from the luminal aspect of ovine large blood vessels after decompression: The effect of mechanical disturbance.

Bubbles nucleate and develop after decompression at active spots on the luminal aspect of ovine large blood vessels. Series of bubbles were shown to detach from the active spot with a mean diameter of 0.7-1.0mm in calm conditions. The effect of mechanical disturbance (striking the bowl containing the vessel or tangential flow) was studied on ovine blood vessels stretched on microscope slides and photographed after hyperbaric exposure. Diameter on detachment after a heavy blow to the bowl was 0.87 ± 0.43 mm (mean ± SD), no different from bubbles which detached without striking the bowl (0.86 ± 0.28 mm). Bubble diameter on detachment during pulsatile tangential flow at 234 cm/min, 0.99 ± 0.36 mm, was not smaller than that seen in the same blood vessels in calm conditions (0.81 ± 0.34 mm). The active spots were stained for lipids, proving their hydrophobicity. The most abundant active spots, which produced only a few bubbles, did not stain for lipids thereafter. The possibility that phospholipids were removed along with detached bubbles may correlate with acclimation to diving. The finding of bubble production at the active spots matches observed phenomena in divers: variable sensitivity to decompression, acclimation to diving, the effect of elevated gas load on increased bubble formation, a higher bubble score in the second dive on the same day, and unexplained neurological symptoms after decompression. Large bubbles released from the arterial circulation give serious cause for concern.

Design and application of pulse information acquisition and analysis system with dynamic recognition in traditional Chinese medicine.

BACKGROUND: To design the pulse information which includes the parameter of pulse-position, pulse-number, pulse-shape and pulse-force acquisition and analysis system with function of dynamic recognition, and research the digitalization and visualization of some common cardiovascular mechanism of single pulse. METHODS: To use some flexible sensors to catch the radial artery pressure pulse wave and utilize the high frequency B mode ultrasound scanning technology to synchronously obtain the information of radial extension and axial movement, by the way of dynamic images, then the gathered information was analyzed and processed together with ECG. Finally, the pulse information acquisition and analysis system was established which has the features of visualization and dynamic recognition, and it was applied to serve for ten healthy adults. RESULTS: The new system overcome the disadvantage of one-dimensional pulse information acquisition and process method which was common used in current research area of pulse diagnosis in traditional Chinese Medicine, initiated a new way of pulse diagnosis which has the new features of dynamic recognition, two-dimensional information acquisition, multiplex signals combination and deep data mining. CONCLUSIONS: The newly developed system could translate the pulse signals into digital, visual and measurable motion information of vessel.

A randomised controlled trial evaluating the effect of potassium supplementation on vascular function and the renin-angiotensin-aldosterone system.

There is limited evidence on the effect of potassium supplementation on the vasculature in patients at increased cardiovascular risk. Potassium increases aldosterone and there is a strong association of hyperaldosteronism with poor cardiac outcomes. We aimed to determine whether potassium supplementation has a significant medium-term effect on aldosterone levels and, if so, what the overall effect of this is on vascular function in patients at moderate cardiovascular disease risk. Forty patients at moderate cardiovascular disease risk were included in a randomised placebo-controlled crossover study. Patients were assigned to 64 mmol potassium chloride or placebo for 6 weeks. Vascular function was assessed using pulse-wave analysis including the detection of a change in augmentation index to salbutamol and nitroglycerine-induced vasodilation. There was no change in augmentation index with potassium vs placebo (25.2±1.4 vs. 26.0±1.3%, respectively). Potassium improved brachial systolic blood pressure (131.8±2.2 vs. 137.1±2.4 mm Hg; P=0.013), central systolic blood pressure (123.2±2.3 vs. 128.4±2.3 mm Hg; P=0.011) and central diastolic blood pressure (80.3±1.3 vs. 83.7±1.4 mm Hg; P=0.019). Plasma renin activity and serum aldosterone both increased with potassium (P=0.001 and P=0.048 respectively). We found that potassium supplementation had no effect on endothelial function or pulse-wave analysis. It lowered brachial systolic and central blood pressure. It was associated with increased plasma renin activity and serum aldosterone.

Effects of acupuncture on the harmonic components of the radial arterial blood-pressure waveform in stroke patients.

MOTIVATION: Stroke induces abnormal microcirculatory blood flow perfusion resistance in cerebral vascular beds, which may in turn alter the arterial pulse transmission. This study aimed to determine if the frequency-domain harmonic index for the blood-pressure waveform is useful in monitoring the microcirculatory blood flow perfusion response in cerebral vascular beds of stroke patients following acupuncture stimulation. METHODS: Bilateral radial arterial blood-pressure waveform and laser-Doppler flowmetry signals were obtained noninvasively before and after acupuncture in 17 stroke patients. The amplitude proportion (Cn) for all the acquired pulses and the coefficient of variance (CVn) for harmonics 1-10 were calculated to evaluate the blood-pressure harmonic variability. RESULTS: The laser-Doppler flowmetry parameters showed that the cerebral microvascular blood flow supply could be improved following acupuncture. For the blood pressure waveform harmonic index, there were significant increases in C5 and C6 and decreases in CV5 and CV7 on the stroke-affected side, but no significant changes on the contralateral side. CONCLUSION: Cn values might reflect changes in arterial pulse transmission, and the blood-pressure-harmonic-variability response might be partly attributable to cardiovascular regulatory activities caused by acupuncture-induced changes in the cerebral microvascular blood flow perfusion. The present findings of blood pressure waveform harmonic analysis may be useful to the development of a noninvasive and real-time technique for evaluating treatment efficacy in stroke patients.

Change of pulsatility index of the fetal middle cerebral artery after auditory stimulation in no risk pregnancies and in pregnancies with gestational hypertension.

PURPOSE: An aim was to determine the degree and the mode of variation of PI of middle cerebral artery in no risk pregnancies and in pregnancies with gestational hypertension, after the constant sound stimuli. METHOD: Study included 343 patients divided in two groups. Group 1: low risk pregnancies and group 2: gestational hypertension. Ultrasound prenatal auditory screening was performed after the 27th week of gestation. RESULTS: The percentage of fetuses with increase of cerebral blood flow was slightly higher in the pregnancies with hypertension. CONCLUSION: An average change of PI of median cerebral artery was higher in this group.

Aromatase inhibition causes increased amplitude, but not frequency, of hypothalamic-pituitary output in normal women.

OBJECTIVE: To better understand the site and mode of action of aromatase inhibitors. DESIGN: Prospective study. SETTING: Academic research environment. PATIENT(S): Five eumenorrheic (without polycystic ovary syndrome), early follicular phase women with a normal body mass index (mean: 20.47±0.68 kg/m2), and 12 normal weight, midreproductive aged, early follicular phase women with a normal body mass index (mean: 20.8±1.7 kg/m2) as historical controls. INTERVENTION(S): 2.5 mg letrozole daily for 7 days, with daily urine collection (first morning void), thrice weekly blood sampling, and 4 hours of blood sampling every 10 minutes. MAIN OUTCOME MEASURE(S): Serum luteinizing hormone (LH) measured by a well-characterized immunofluorometric assay with LH pulse characteristics compared between treated and control groups using t tests. RESULT(S): Mean LH and LH pulse amplitude more than doubled in the women who had taken letrozole compared with the controls, but the LH pulse frequency did not differ between the women taking letrozole and the controls. CONCLUSION(S): These results indicate that the release of negative feedback inhibition of estradiol on the hypothalamic-pituitary axis in normal women by aromatase inhibitors creates an amplitude-related increase in endogenous hypothalamic-pituitary drive. The finding that the mean LH and LH pulse amplitude, but not the frequency, increased after letrozole suggests a possible pituitary site of action.

Changes in umbilical venous volume flow after fetoscopic laser occlusion of placental vascular anastomoses in twin-to-twin transfusion syndrome.

OBJECTIVE: To examine effects of fetoscopic laser occlusion of placental vascular anastomoses on umbilical venous volume flow in twin-to-twin transfusion syndrome. STUDY DESIGN: Absolute umbilical venous volume flow, measured preoperatively and 48 hours after fetoscopic laser occlusion was related to Doppler studies, bladder filling in donors, and anastomoses. RESULTS: Among 45 patients, recipients had decreased ductus venosus pulsatility index (ductus venosus-pulsatility index for veins, 1.16 vs 1.01; P < .001) and unchanged umbilical venous volume flow after fetoscopic laser occlusion (74.7 vs 74.5 mL; P = .407). Donors had decreased umbilical artery pulsatility (1.34 vs 1.11; P = .008), increased ductus venous-pulsatility index for veins (0.75 vs 0.91; P < .014), and significantly increased umbilical venous volume flow per kilogram by 52.3% (136.6 vs 208.0 mL/Kg/min; P < .001). Donor bladder filling occurred at higher umbilical venous volume flow per kilogram (142.7 vs 221.4 mL/Kg/min; P < .012). Increase in umbilical venous volume flow per kilogram correlated with the net difference in arteriovenous anastomoses (Pearson r = 0.403, P = .006). CONCLUSION: Fetoscopic laser occlusion in twin-to-twin transfusion syndrome corrects intertwin differences in umbilical venous volume flow by predominant effects in the donor. Reappearance of donor bladder filling correlates with correction of volume flow.

[Feature extraction and recognition of traditional Chinese medicine pulse based on hemodynamic principles].

In this paper, factors contributing to the formation of pulse wave were analyzed based on hemodynamic principles. It is considered that formation of pulse wave was related to its propagation and reflection characteristics. Propagation of the pulse wave was characterized by pulse wave velocity, and reflection of the pulse wave was characterized by reflection coefficient. Pulse wave velocity and reflection coefficient were proposed as the eigenvectors of pulse wave in pulse diagnosis of traditional Chinese medicine, and support vector machine (SVM) was used to recognize slippery pulse, stringy pulse and plain pulse. Pulse wave velocity and reflection coefficient of the slippery, stringy and plain pulses in healthy people were calculated in this study, and SVM with Gaussian radial basis function was used for classifying. Results showed that pulse wave velocity and reflection coefficient with physiological and pathological significance had advantages in distinguishing slippery pulse, stringy pulse and plain pulse, which offered a new idea for recognizing pulse condition.

The relationship between n-3 long-chain polyunsaturated fatty acids and pulse wave velocity in diabetic and non-diabetic patients under long-term hemodialysis. A horizontal study.

BACKGROUND: Diabetes mellitus (DM) and deficiency in n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFAs) are known to increase the incidence of cardiovascular disease (CVD). However, it has not yet been reported whether n-3 LCPUFAs are related to arteriosclerosis in patients under long-term hemodialysis (HD). METHODS: Pulse wave velocity from the brachium to the ankle (baPWV) was measured as a marker of arteriosclerosis with a volume-plethysmographic apparatus in 147 long-term HD patients (non-diabetic (non-DM): 51 males/42 females, 62 +/- 14 y; and DM: 33 males/21 females, 67 +/- 9 y). The fatty acid composition of the total phospholipid fraction from washed RBCs was analyzed by gas chromatography. Analyses were adjusted for age, sex, diastolic blood pressure, pulse, body mass index, duration of HD treatment, smoking status, LDL/HDL-cholesterol ratios and diabetes mellitus (DM). RESULTS: The mean baPWV was 18.9 +/- 5.2 and 23.7 +/- 6.3 m/s in non-DM and DM patients, respectively. The mean baPWV in DM patients was significantly higher than that of non-DM patients after adjustment (p = 0.0002). Multiple regression analysis showed that there was a significant inverse association between baPWV and docosahexaenoic acid (DHA) levels (p = 0.017) and DHA/arachidonic acid (AA) ratios (p = 0.012) in RBC in non-DM patients after adjustment but not in DM patients. CONCLUSIONS: We suggest that n-3 LCPUFAs may be a negative risk factor of CVD also in non-DM HD patients. In DM patients the effects of n-3 PUFAs on the vascular system became undetectable probably because DM overwhelmingly affected PWV. Further studies in a prospective manner are necessary.

MR imaging and quantification of the movement of the lamina terminalis depending on the CSF dynamics.

BACKGROUND AND PURPOSE: Brain pulsation is a well-known observation in neurosurgery, but methods for its visualization on MR imaging, like phase imaging, do not provide a detailed structural view. We prospectively investigated electrocardiographic (ECG)-gated cine true fast imaging with steady-state precession (FISP) sequence on volunteers to test a sequence for demonstrating brain pulsation and movements of intracranial structures related to CSF dynamics. MATERIALS AND METHODS: Eleven healthy volunteers were investigated with prospectively ECG-gated cine true-FISP in the midsagittal plane. A total of 50 phases were recorded per cardiac cycle and per volunteer. The lamina terminalis was chosen to study the pulsatility of the brain, and the optic recess diameter was chosen for means of objective quantification of the degree of pulsatility. RESULTS: Pulsatile motion of the lamina terminalis was apparent in all volunteers on the cine mode. The mean diameter of the optic recess was 2.5 mm. The greatest change in diameter in 1 volunteer was 1.5 mm. The mean change in diameter was 40% during 1 cardiac cycle. CONCLUSIONS: Cine true-FISP sequence is a well-suited method for investigations of passive movements of the ventricular system. It shows pulsations of the brain as well as passive changes caused by CSF dynamics with high temporal and spatial resolution.

[Pulse wave: the bridge connecting traditional Chinese medicine with Western medicine].

Pulse wave, a research focus in both traditional Chinese medicine and Western medicine, which contains a wealth of human physiological and pathological information, has always been the concern of medical practitioners. On the basis of the review on the development of the pulse wave theory and its applications, the existing problems in this field are discussed in this paper. On the basis of the status quo of pulse wave information extraction methods and the utilization of pulse wave in traditional Chinese and Western medicine, a more in-depth study on pulse wave is proposed to make it a bridge connecting traditional Chinese medicine with Western medicine.

[A new opinion on detection methods for pulse shape and pulse force].

Pulse shape and pulse force are difficult to detect in pulse taking study. But the application of visualized technology extends the space acquisition of pulse taking information, and it is possible to realize the objective detection of pulse shape and pulse force. Rational research thoughts and strategies could be informed by combining image information and other data, and it is a necessary method in implementing the objective detection of pulse.

Acute combined effects of olive oil and wine on pressure wave reflections: another beneficial influence of the Mediterranean diet antioxidants?

OBJECTIVES: Combined consumption of olive oil and wine is common in the Mediterranean diet, but there are no data concerning their synergistic haemodynamic response. We sought to determine the combined postprandial effects of wine and olive oil on wave reflections and central haemodynamics. METHODS: Fifteen healthy subjects consumed four standard meals on different days, containing 50 g of olive oil and 250 ml of wine, in a randomized cross-over study design. Two types of wine [red (R) and white (W)] and two types of olive oil [green (G) and refined (O) (rich and poor in antioxidants, respectively)] were used in all possible combinations (RO, RG, WO and WG). Applanation tonometry and aortic pulse wave analysis were performed when fasting and 1, 2 and 3 h postprandially. A second group of 15 healthy individuals matched for age, gender and body mass index served as the control group. RESULTS: All meals decreased AIx (RO and RG, P < 0.001; WO, P = 0.007; and WG, P = 0.039). The AIx reduction after RG, RO, WO and WG was significantly different from the respective AIx response of the control group. No difference was observed in the reduction of AIx between sessions, but a significantly earlier peak decrease in AIx, as well as a more prolonged decreasing effect, was observed after RG and RO consumption compared to WO and WG. Central systolic and diastolic pressures were diminished after all four combinations of wine and olive oil (P < 0.05). CONCLUSIONS: Combined consumption of wine and olive oil provided beneficial postprandial effects on haemodynamics. These findings reveal an additional favourable effect of components of the Mediterranean diet on haemodynamics in the postprandial state.

Doppler study of splanchnic hemodynamics in Hirschsprung's disease.

BACKGROUND: Doppler studies of splanchnic vessels have demonstrated alteration in blood flow in bowel obstruction and strangulation. The aim of this study was to evaluate hemodynamic changes in celiac artery (CA), superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) using pulsed Doppler sonography (PDS) in Hirschsprung's disease. MATERIAL AND METHODS: Fasting splanchnic flowmetry of CA, SMA, and IMA arteries was performed using PDS preoperatively in 13 patients with Hirschsprung's disease and 13 healthy age- and sex-matched controls. Diagnostic workup for Hirschsprung's disease included a barium enema and a rectal biopsy. A primary transanal pull through was performed if the transition zone was at rectosigmoid or midsigmoid. Doppler studies were repeated on the 1st and 7th postoperative day under similar conditions. Mean flow velocity (V(mean)) and the pulsatility index (PI) of the three major vessels was measured. RESULTS: Patients with Hirschsprung's disease showed increased blood flow velocities in CA, SMA, and IMA (p < 0.001), an increased resistance to blood flow in IMA (p < 0.001) and a decreased resistance to blood flow in CA and SMA (p < 0.005 and p < 0.001, respectively). The blood flow velocity for IMA normalized after resection of the aganglionic segment (r = 0.41, p < 0.005, 95% CI: 45.4-52.7). CONCLUSIONS: Hirschsprung's diseaseis associated with alterations in splanchnic vessel hemodynamics which are reversible after corrective surgery. Doppler studies may play an important role in the assessment of bowel function after surgery.

The effect of 4-week chilli supplementation on metabolic and arterial function in humans.

OBJECTIVE: To investigate the effects of regular chilli ingestion on some indicators of metabolic and vascular function. DESIGN: A randomized cross-over dietary intervention study. SETTING: Launceston, Australia. SUBJECTS: Healthy free-living individuals. INTERVENTION: Thirty-six participants (22 women and 14 men), aged 46+/-12 (mean+/-s.d.) years; BMI 26.4+/-4.8 kg/m(2), consumed 30 g/day of a chilli blend (55% cayenne chilli) with their normal diet (chilli diet), and a bland diet (chilli-free) for 4 weeks each. Metabolic and vascular parameters, including plasma glucose, serum lipids and lipoproteins, insulin, basal metabolic rate, blood pressure, heart rate, augmentation index (AIx; an indicator of arterial stiffness), and subendocardial-viability ratio (SEVR; a measure of myocardial perfusion), were measured at the end of each diet. In a sub-study, during week 3 of each dietary period, the vascular responses of 15 subjects to glyceryl-trinitrate (GTN) and salbutamol were also studied. RESULTS: For the whole group, there were no significant differences between any of the measured parameters when compared at the end of the two dietary periods. When analysed separately, men had a lower resting heart rate (P=0.02) and higher SEVR (P=0.05) at the end of the chilli diet than the bland diet. In the sub-study, baseline AIx on the chilli diet was lower (P<0.001) than on the bland diet, but there was no difference in the effects of GTN and salbutamol between the two diets. CONCLUSION: Four weeks of regular chilli consumption has no obvious beneficial or harmful effects on metabolic parameters but may reduce resting heart rate and increase effective myocardial perfusion pressure time in men.

Effect of chronic coffee consumption on aortic stiffness and wave reflections in hypertensive patients.

OBJECTIVE: Aortic stiffness and wave reflections are important markers and prognosticators of cardiovascular risk. Caffeine increases acutely aortic stiffness and wave reflections. Furthermore, chronic coffee consumption is associated with increased aortic stiffness and wave reflections in normotensive subjects. In the present study, we aimed to assess the association between chronic coffee consumption, and aortic stiffness and wave reflections in hypertensive patients. DESIGN: Epidemiological survey. SETTING: Hypertension Unit, University Hospital. SUBJECTS-METHODS: We examined 259 never-treated hypertensives (age 50+/-12 years, 165 males) without diabetes mellitus, who were asked to describe in detail the type and amount of coffee they consumed. Carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx) were measured non-invasively as indices of aortic stiffness and wave reflections, respectively. RESULTS: When controlled for gender, age, height, smoking status, heart rate, mean pressure, HDL cholesterol and hsCRP, AIx was found to be higher with increasing daily coffee consumption. Post hoc analysis revealed that all groups of coffee consumption had higher AIx compared to no-consumption. PWV did not differ among groups of daily coffee consumption. Each participant had 35% higher relative risk of having high AIx for each cup (150 ml) of coffee per day, and 40% higher relative risk for each 10 cup-years. CONCLUSIONS: Coffee consumption is associated with increased wave reflections, but not aortic stiffness in never-treated hypertensive patients. This finding may have important clinical implications for cardiovascular health in hypertensive subjects.

Different patterns of pulse spectrum between survivors and non-survivors during progressive hemorrhage in rats.

Previous work from our laboratory has demonstrated that the percentage differences of 2nd (C2) and 3rd (C3) pulse harmonics related to Kidney and Spleen were both increased toward another steady state in rats after acute hemorrhage. Therefore, it is suggested that changes in pulse spectra might represent the ability of animals to survive a model of progressive hemorrhage. In this study, the difference of the pulse spectra patterns between survivors and non-survivors after progressive hemorrhage (by loss of 5%, 10% or 20% of the estimated blood volume) in anesthetized rats is determined. Seven rats, dead within 2 hours after a loss of 20% of the estimated blood volume hemorrhage, were defined as 'non-survivors'. The other eleven rats, more than 2 hours after hemorrhage, were defined as 'survivors'. Pulse waves of arterial blood pressure before and after the hemorrhage were measured in parallel to the pulse spectrum analysis. Data among different phases were analyzed using one-way analysis of variance (ANOVA) with Duncan's test for pairwise comparisons. Differences between survivor and non-survivor groups at each phase were analyzed using Student's t-test. A mixed-effects linear regression model was applied to evaluate the relationship in harmonics, which significantly differed between the two groups. The study results showed that in rats, during progressive hemorrhage, the percentage differences of 2nd harmonic proportion increased significantly; however, the result failed to show any significant difference between survivors and non-survivors. After the third blood withdrawal process, the percentage differences of 3rd harmonic proportion increased more significantly in the survivors. In addition, the percentage differences of 1st harmonic proportion related to the Liver for the survivor group was significantly lower than that of the non-survivors. After analysis with the mixed linear regression model, C3 and C1 demonstrated a linear regression relationship, and there existed significant differences between survivors and non-survivors. These results suggest that C3 might play an important role in physiology regarding surviving capability after progressive hemorrhage.