Reduction In Pulsatility Index Research Articles

Aerobic exercise training enhances cerebrovascular pulsatility response to acute aerobic exercise in older adults.

The brain's low resistance ensures a robust blood flow throughout systole and diastole and is susceptible to flow pulsatility. Increased cerebral pulsatility contributes to the progression of cerebrovascular disease. Although aerobic exercise affects vascular function, little is known about the effect of exercise on the cerebral pulsatility index in older adults. The aim of this study was to investigate the effect of exercise training on the post‐exercise cerebral pulsatility response in older adults. Ten healthy older adults participated in a 12‐week exercise training intervention. Before and after the intervention, we measured the pulsatility index of the middle cerebral artery by means of transcranial Doppler method at baseline and following a cycling exercise bout performed at an intensity corresponding to the ventilatory threshold. Before exercise training, there was no significant change in the cerebral pulsatility response to an acute bout of cycling exercise. However, after the intervention, cerebral pulsatility decreased significantly following 30 min of an acute cycling exercise (P < 0.05). This study demonstrated that cerebral pulsatility index did not change following an acute bout of cycling exercise at an intensity corresponding to ventilatory threshold, but that, after 12 weeks of exercise training, cerebral pulsatility index was reduced at 30 min after a single bout of cycling exercise. These results suggest that long‐term aerobic exercise training may enhance the post‐exercise reduction in pulsatility index in older adults.

Perinatal and Hemodynamic Evaluation of Sildenafil Citrate for Preeclampsia Treatment: A Randomized Controlled Trial.

To evaluate whether therapy with sildenafil citrate prolongs gestation in women with preeclampsia. In a randomized double-blind, placebo-controlled trial, 100 singleton pregnancies with preeclampsia between 24 and 33 weeks of gestation were randomized to 50 mg oral sildenafil citrate every 8 hours or placebo. The primary outcome was prolongation of pregnancy from randomization to delivery. Secondary outcomes were changes in resistance indices of uterine, umbilical, and middle cerebral arteries by Doppler, fetal and maternal complications, and adverse neonatal outcomes. Power analysis estimated that to detect a difference of 5 days in pregnancy duration, 43 patients would have to be randomized to each group. From June 2013 to October 2015, 50 patients were randomized to each group. Pregnancy duration was on average 4 days longer (14.4 days, 95% confidence interval [CI] 12.5-16.6 days compared with 10.4 days, 95% CI 8.4-12.3 days, P=.008) and percent reduction in pulsatility indices of uterine and umbilical arteries higher (22.5% and 18.5%, compared with placebo 2.1% and 2.5%, P<.001) for patients treated with sildenafil compared with placebo. Maternal blood pressure before and 24 hours after randomization was lower with sildenafil (sildenafil: 100.3±5.6 mm Hg compared with 116.4±5.1 mm Hg, P<.05; placebo: 110.6±6.2 mm Hg compared with 114.7±6.5 mm Hg, P=.21). There was no difference in perinatal morbidity, mortality, or adverse effects between groups. Therapy with sildenafil citrate was associated with pregnancy prolongation of approximately 4 days compared with placebo in women with preeclampsia. Brazilian Registry of Clinical Trials, www.ensaiosclinicos.gov.br, RBR-8qj4p5.

Prediction of pulmonary hypoplasia in mid‐trimester preterm prelabor rupture of membranes: research or clinical practice?

Prediction of pulmonary hypoplasia in mid‐trimester preterm prelabor rupture of membranes: research or clinical practice?

Fetal hemodynamic changes after amniotomy

The aim of the study was to assess fetal vascular blood flow after amniotomy. This was a prospective observational study. Thirty-five women with singleton pregnancy beyond 36 weeks of gestation, who underwent amniotomy, were recruited. The pulsatility indices of the fetal middle cerebral artery (MCA), the renal artery, and the ductus venosum were measured before and 30 min following amniotomy. The changes in pulsatility index were compared by means of Wilcoxon signed rank test. There was a significant reduction in pulsatility indices of the MCA (median reduction: 0.23; interquantile range (IQR): -0.04, 0.4) and the renal artery (median reduction: 0.12; IQR: -0.12, 0.54) after amniotomy. However, there was no obvious change in the ductus venosum (median reduction: 0.00; IQR: -0.06, 0.1). Amniotomy is associated with significant reduction in the impedance of the fetal MCA and the renal artery. The former may be a result of fetal stress response and the latter could be related to the release of vasoactive substances after amniotomy.

Fetal hemodynamic changes after amniotomy

Background. The aim of the study was to assess fetal vascular blood flow after amniotomy. Methods. This was a prospective observational study. Thirty-five women with singleton pregnancy beyond 36 weeks of gestation, who underwent amniotomy, were recruited. The pulsatility indices of the fetal middle cerebral artery (MCA), the renal artery, and the ductus venosum were measured before and 30 min following amniotomy. The changes in pulsatility index were compared by means of Wilcoxon signed rank test. Results. There was a significant reduction in pulsatility indices of the MCA (median reduction: 0.23; interquantile range (IQR): −0.04, 0.4) and the renal artery (median reduction: 0.12; IQR: −0.12, 0.54) after amniotomy. However, there was no obvious change in the ductus venosum (median reduction: 0.00; IQR: −0.06, 0.1). Conclusions. Amniotomy is associated with significant reduction in the impedance of the fetal MCA and the renal artery. The former may be a result of fetal stress response and the latter could be related to the release of vasoactive substances after amniotomy.

Acupuncture and good prognosis IVF patients: Synergy

To determine the role of electro stimulation acupuncture and traditional combined with auricular acupuncture on IVF outcomes in good prognosis patients. Retrospective case controlled clinical study. Acupuncture Consortium for treatment standardization. Reproductive EndocrinologysInfertility IVF Private Practice and Traditional Chinese Medicine Acupuncture Clinics. One hundred fourteen infertile patients undergoing controlled ovarian hyperstimulation with gonadotropins and GnRH agonist and antagonist for IVF-ET (2001 to 2003) in private practice IVF clinic. Only IVF patients with normal Day 3 FSH, normal uterine artery pulsatility indices, sperm morphologies over 7% normal by Kruger Strict Criteria and good response to ovarian hyperstimulation protocols (i.e., E2 over 2000 pg/ml) were analyzed.Intervention (s): Electrostimulation acupuncture -- reduction of Pulsatility Index (PI) of the uterine artery and Traditional combined with Auricular acupuncture -- Pre/Post embryo transfer protocols were used alone or in combination and resultant pregnancy outcomes were measured after IVF treatments. Main Outcome Measure(s): Cycles were grouped according to those that received No Acupuncture (Non-Ac) and those that received either one or both acupuncture treatments (Ac). Comparisons were made between Acupuncture treated IVF patients and Non − Acupuncture treated IVF patients in clinical pregnancies, ongoing pregnancies and birth outcomes. The statistics used for this analysis included; Tests for normal distribution: chi-square test, Kolmogorov-Smirnov Test Unpaired T-tests Stepwise Multiple regression Variance ratio test (F-Test) One-Way analysis of variance (ANOVA) with Student-Newman-Keuls (SNK) test for pair wise comparison of subgroups. Total IVF cases 114, 53 with Acupuncture (Ac) and 61 without Acupuncture (Non-Ac). Demographics, Infertility Diagnoses, and Treatment Protocols were statistically the same between both groups and by design, the following parameters were similar: Sperm Morphology; Peak Day 3 FSH; Average Pulsatility Index; Peak E2 at hCG; and Post hCG P4. These parameters earned the designation of Good Prognosis group. Pregnancy rates (PR) and Miscarriage rates (SAB) were statistically improved at the p < 0.05 levels in those patients that received Acupuncture (51% v 36% PR and 8% v 20% SAB in the AC v Non-Ac groups). There were no ectopic pregnancies in the Ac group and 9% in the Non-Ac group, p < 0.008. Finally, Birth rates (BR) per cycle start and per pregnancy were significantly higher in the Ac group, with 23% more births/pregnancy significant at the p < 0.05 level. The use of adjunctive therapies in IVF protocols is gaining popularity. In previously published data, Acupuncture was reserved for Poorer Prognosis patients and enhanced outcomes were observed. In this study, we demonstrated that Good Prognosis patients would also benefit from inclusion of published Acupuncture protocols. This is also the first publication of Birth outcome data in Acupuncture treated IVF patients. Acupuncture significantly increased birth outcomes; it significantly decreased ectopic pregnancies and miscarriage rates. These data uniquely support a definitive role of both Electrostimulation and Traditional combined with Auricular Acupuncture in IVF in Good Prognosis IVF patients.

External cephalic version induced fetal cerebral and umbilical blood flow changes are related to the amount of pressure exerted.

To correlate the applied pressure during external cephalic version with the changes in fetal middle cerebral arterial and umbilical arterial flow before and after the procedure. A prospective observational study over a two-year period. External cephalic version was performed in a university hospital. Sixty-nine women with singleton breech-presenting pregnancy at or above 36 weeks of gestation undergoing external cephalic version. During external cephalic version, the operator wore a pair of pressure-sensing gloves which had thin piezo-resistive sensors positioned on the palmar surface. During each version procedure, real-time pressure readings were recorded from all sensors, and then analysed with a computer program. The amount of pressure applied over time was presented by pressure-time integral. The pulsatility indices of both fetal middle cerebral artery and umbilical artery before and after external cephalic version were measured. The changes of pulsatility indices of both middle cerebral artery and umbilical artery were presented as a ratio of the post-external cephalic version pulsatility indices to pre-external cephalic version pulsatility indices, denoted by middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio, respectively. The statistical correlation between pressure-time integral and middle cerebral artery pulsatility index ratio and umbilical artery pulsatility index ratio are analysed using Pearson's correlation test. Changes in pulsatility indices of fetal middle cerebral and umbilical arteries and fetal heart rate after external cephalic version. The overall success rate of external cephalic version was 77%. There was a significant negative correlation between pressure-time integral and both middle cerebral artery pulsatility index ratio (P= 0.001) and umbilical artery pulsatility index ratio (P= 0.012). When women were categorised according to placental site, pressure-time integral was negatively correlated with middle cerebral artery pulsatility index ratio only when the placenta was posteriorly located (P= 0.003), and with umbilical artery pulsatility index ratio only when the placenta was laterally located (P= 0.03). The greater the force applied during external cephalic version, the greater the reduction in pulsatility indices of middle cerebral artery and umbilical artery, indicating an increase in blood flow through these arteries. The increase in cerebral blood flow after external cephalic version is more prominent when the placenta is lying posteriorly, while the increase in umbilical flow is more prominent when the placenta is lying laterally. These findings suggest that the vascular changes probably represent a direct effect of force exerted on the fetal head and the placenta.

Effect of external cephalic version at term on fetal circulation

Objective: We sought to investigate the subclinical effect of external cephalic version on fetal circulation. Study Design: A prospective observational study was conducted on 136 subjects who had external cephalic version at or beyond 36 weeks of gestation without clinical complication. Doppler ultrasonographic studies of the umbilical and middle cerebral circulations were performed before and after the external cephalic version. The following Doppler indexes were measured: (1) the pulsatility index of the umbilical artery, which represents disturbance of placental circulation, and (2) the pulsatility index of the fetal middle cerebral artery, which represents fetal response. The Wilcoxon signed rank test was used for all statistical analyses. Results: There was no significant difference in pulsatility index of the umbilical artery before and after external cephalic version ( P = .674). There was a statistically significant reduction in the pulsatility index of the middle cerebral artery after external cephalic version ( P = .043), and this difference existed only among multiparous women ( P = .029), among those in whom the external cephalic version was considered to be difficult ( P = .038), and when the placenta was posteriorly located ( P = .028). The reduction in pulsatility index was not related to whether the external cephalic version was successful. In all cases the Doppler indexes remained within the normal ranges, and there were no associated fetal complications. Conclusion: External cephalic version was not associated with any significant disturbance of placental resistance to blood flow. Conversely, external cephalic version was associated with a significant reduction in the pulsatility index of the middle cerebral circulation, especially among the multiparous women, after a difficult procedure or in those with a posterior placenta. This probably represents a normal fetal physiologic response to manipulation of the fetal head. (Am J Obstet Gynecol 2000;182:1239-42.)

Doppler ultrasonographic evaluation of splanchnic blood flow in coeliac disease.

Current knowledge on splanchnic haemodynamics in coeliac disease is limited and incomplete. To evaluate splanchnic arterial and venous blood flow in coeliac disease. In 22 coeliac (13 untreated, nine treated) patients and in nine healthy subjects the following variables were assessed: vessel diameter and mean flow velocity in portal vein, splenic vein, superior mesenteric vein, and superior mesenteric artery. Peak systolic velocity, end diastolic velocity and pulsatility index were also determined in the superior mesenteric artery. Five patients of the untreated group were re-evaluated after nine months on a gluten free diet. Significant differences in haemodynamic variables between the three groups were shown only in the superior mesenteric artery. An increase in both mean flow velocity and end diastolic velocity and a reduction in pulsatility index occurred in untreated patients compared with treated patients (p < 0.002; p < 0.04; p < 0.035) and with healthy controls (p < 0.001; p < 0.025; p < 0.0003). Similar results were obtained for the five patients evaluated before and after treatment (p < 0.03; p < 0.02; p < 0.03), in whom the mean flow velocity in the superior mesenteric vein also decreased after treatment (p < 0.05). No significant differences were noted between treated coeliac patients and healthy controls. In untreated coeliac disease there is a hyperdynamic mesenteric circulation that decreases after treatment.

Reverse end-diastolic flow in the middle cerebral artery: An agonal pattern in the human fetus

Serial Doppler ultrasonography in a severely growth-restricted fetus revealed progressive reduction in pulsatility index of the middle cerebral artery, consistent with brain-sparing effect. At 29 weeks, 1 week before fetal death, the pulsatility index in the middle cerebral artery returned to normal values and became reversed the day before fetal death. This report suggests that reverse flow in the middle cerebral artery is one of the terminal hemodynamic events preceding fetal death. (A M J O BSTET G YNECOL 1996;174:1645-7.)

Chronic cerebral hypotension induces a downward shift of the cerebral autoregulation: a hypothesis based on TCD and OPG-GEE studies in ambulatory patients with occlusive cerebrovascular disease.

In order to establish whether or not the cerebral autoregulation is still effective at blood pressure rates in those who experience a chronic cerebral hypotension 37 patients were subjected to noninvasive CO2 enhanced transcranial Doppler (TCD) and ocular pneumoplethysmographic (OPG-GEE) studies of the middle cerebral and ophthalmic arteries. The patients demonstrating a combination of a unilateral patent internal carotid artery (ICA diameter reduction less than 49%) and a contra-lateral ICA occlusion based on duplex scan examinations were examined. The cerebral blood flow velocities at normocapnia (BFV) and pulsatility indices (PI) were measured by TCD. An equivalent of the reserve capacity of the cerebral autoregulation was estimated by quantification of the CO2 enhanced cerebral vasomotor reactivity (VMR). Cerebral blood pressure equivalents such as the OSP/BSP ratio and the ophthalmo-brachial systolic pressure (OBSP) index were estimated by measuring the ocular systolic blood pressure (OSP) and the systemic systolic blood pressure (BSP). The TCD and OPG-GEE data are both in the normal range distally to a patent ICA (n = 22). If the ICA is occluded the OPG-GEE data show a significant reduction in both OSP/BSP ratio's and OBSP indices. If the VMR was in the normal range, distally to an occluded ICA (n = 25), the pressure drop was mild and the BFV at rest was in the normal range. Nevertheless, the waveforms were more damped as seen from the reduction in pulsatility indices but the reduction did not reach statistical significance when compared to the PI values distally to a patent ICA.(ABSTRACT TRUNCATED AT 250 WORDS)

The blood flow velocity waveform in the fetal descending aorta; its relationship to fetal heart rate pattern, eye and body movements in normal pregnancy at 27–28 weeks of gestation

In 13 normal pregnancies at 27–28 weeks of gestation the blood flow velocity waveform at the lower thoracic level of the fetal descending aorta was studied in relation to fetal heart rate pattern (FHRP), fetal eye movements (FEM) and fetal body movements (FBM). State parameter combinations in which high fetal heart rate (FHR) variability was present, were associated with a significant reduction in pulsatility index (PI) as compared with periods in which low FHR variability was present, irrespective of FEM and FBM, indicating a reduced peripheral vascular resistance. At 27–28 weeks of gestation FHR variability and PI might be linked to baroreceptor sensitivity. PI values derived from combinations FHRP-A, FEM(—), FBM(-) and FHRP-B, FEM(+), FBM(+) showed a significant inverse relationship (P < 0.05) with FHR. FHR and FHR variability should be taken into account when studying flow velocity waveforms in the fetal descending aorta at 27–28 weeks of gestation.