Total Arterial Blood Research Articles

Ultrasonographic Assessment of Testicular Biometry and Arterial Blood Flow in Pre- and Postpubertal Miranda Donkeys: Correlations With Semen Quality Parameters.

The main goals of this study were to document and compare the normal ranges of testicular haemodynamic parameters in pre- (aged 8-12 months; n = 4) and postpubertal (aged 24-259 months; n = 16) Miranda donkeys in the breeding season, and to correlate animal biometric data and testicular Doppler indices with basic semen quality parameters of sexually mature jacks. Colour and pulsed-Doppler ultrasonography were employed to assess blood flow in the left and right distal supratesticular artery (DsTA) and their marginal branches (marginal arteries-MA). Peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) and resistive index (RI) were evaluated in both blood vessels, and TAMV (time-averaged mean velocity), TABF (total arterial blood flow) and TABF rate (TABF-R) were calculated for MA. The mean diameter of MA was greater (p < 0.05; 0.24 ± 0.05 vs. 0.19 ± 0.05 cm; mean ± SD) but TABF-R was less (p < 0.05; 0.004 ± 0.004 vs. 0.02 ± 0.01 mL/s/cm3) in sexually mature donkeys compared with prepubertal animals. Apart from RI values for the right testicle of prepubertal donkeys, PI and RI were consistently greater (p < 0.05) in DsTA compared with MA. Significant correlations were found among select biometric and haemodynamic attributes of the testes (height, width and length, TV, TTV and PSV-ST) and ejaculate characteristics (volume, sperm defects-total, head and midpiece) in sexually mature donkeys (n = 8). The present results highlight the importance of scrotal ultrasonography for the reproductive assessment of jacks and provide reference values, based on the available subpopulation of Miranda donkeys that can be used in their clinical and reproductive management and research, or conservation programmes.

Extended period of ventilation before delayed cord clamping augments left-to-right shunting and decreases systemic perfusion at birth in preterm lambs.

Previous studies have suggested that an extended period of ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. However, it is unknown whether this greater rise in PA flow is accompanied by increases in left ventricular (LV) output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale (FO), with decreased systemic arterial perfusion. Using an established preterm lamb birth transition model, this study compared the effect of a short (∼40s, n=11), moderate (∼2min, n=11) or extended (∼5min, n=12) period of initial mechanical lung ventilation before DCC on flow probe-derived perinatal changes in PA flow, LV output, total systemic arterial blood flow, ductal shunting and FO shunting. The LV output was relatively stable during initial ventilation but increased after DCC, with similar responses in all groups. Systemic arterial flow patterns displayed only minor differences during brief and moderate periods of initial ventilation and were similar after DCC. However, an increase in PA flow was augmented with an extended initial ventilation (P < 0.001), owing to an earlier onset of left-to-right ductal and FO shunting (P < 0.001), and was accompanied by a pronounced reduction in total systemic arterial flow (P=0.005) that persisted for 4min after DCC (P ≤ 0.039). These findings suggest that, owing to increased left-to-right shunting and a greater reduction in systemic arterial perfusion, an extended period of ventilation before DCC does not result in greater perinatal circulatory benefits than shorter periods of initial ventilation in the birth transition. KEY POINTS: Previous studies suggest that an extended period of initial ventilation before delayed cord clamping (DCC) augments birth-related rises in pulmonary arterial (PA) blood flow. It is unknown whether this greater rise in PA flow is accompanied by an increased left ventricular output and systemic arterial perfusion or whether it reflects enhanced left-to-right shunting across the ductus arteriosus and/or foramen ovale, with decreased systemic arterial perfusion. Anaesthetized preterm fetal lambs instrumented with central arterial flow probes underwent a brief (∼40s), moderate (∼2min) or extended (∼5min) period of ventilation before DCC. Perinatal changes in left ventricular output were similar in all groups, but extended initial ventilation augmented both perinatal increases in PA flow, owing to earlier onset and greater left-to-right ductal and foramen ovale shunting, and perinatal reductions in total systemic arterial perfusion. Extended ventilation before DCC does not confer a greater perinatal circulatory benefit than shorter periods of initial ventilation.

Changes in Cardiac Structure and Function Following Fistula Ligation in Kidney Transplant Recipients (Cohort Study)

Purpose: International guidelines recommend that haemodialysis access is provided by an arteriovenous fistula (AVF), which enables frequent, reliable access to the circulation, but there are no guidelines to suggest whether these AVFs need to be ligated after kidney transplantation. Cardiovascular morbidity and mortality remain high in recipients of a kidney transplant, the persistence of a patent arteriovenous fistula (AVF) after transplantation may contribute to ongoing maladaptive cardiovascular remodelling. The ability to reverse this maladaptive remodelling by ligation of this AVF is unknown. We conducted this trial to evaluate the effect of AVF ligation on cardiac structure and function in stable kidney transplant recipients. Also we studied the ability of preoperative echocardiographic and non-invasive hemodynamic measurements, including the effects of acute temporary occlusion of the fistula, to predict postoperative left ventricular diameter and mass reduction, by the closure of the fistula.&#x0D; Materials and Methods: Nonrandomized controlled trial. kidney transplant recipients (&gt;12 months after transplantation with stable graft function) were divided into 2 groups. The first referred for surgical arteriovenous fistula closure. The second group didn’t receive Fistula closure (control). Standard echocardiographic parameters, heart rate, and blood pressure were assessed preoperatively (fistula closure) at baseline. These measurements were repeated 6 months after surgical closure.&#x0D; Findings: Seventeen kidney transplant patients were prospectively studied with 11 case and 6 controls with no fistula closure. Surgical fistula closure decreased left ventricular end-diastolic diameter and mass indexes (29.9_2.4to 27.4_2.1 mm/m2, P&lt;0.001, and 141_37 to 132_39 g/m2, P&lt;0.05, respectively), whereas no changes were seen in controls after a similar delay. Postoperative left ventricular end-diastolic diameter and mass reductions correlated best with the increases in total peripheral resistance (r_0.85, P&lt;0.0001) and mean arterial blood pressure (r_0.64, P_0.006), respectively.&#x0D; Conclusions. Surgical closure of arteriovenous fistula reduces left ventricular diameter and mass in kidney transplant recipients. The best predictors of those morphological changes are the rise in blood pressure and total peripheral resistance induced by temporary occlusion of the fistula.&#x0D; Implications to Theory, Practice and Policy: Surgical closure of persistent AV fistula after renal transplantation to correct LV geometry and improve symptoms in terms of exertional dyspnea and palpitations.

Effect of Acute Melatonin Injection on Metabolomic and Testicular Artery Hemodynamic Changes and Circulating Hormones in Shiba Goats under Sub-Tropical Environmental Conditions.

The beneficial effects of melatonin were investigated to mitigate various detrimental effects and toxicity on reproductive performance. The present study aimed, for the first time, to explore the effect of intravenous melatonin injection on testicular artery hemodynamics (TH) and metabolomic changes, reproductive hormones in heat-stressed bucks. Ten bucks were randomly split into two groups (five each): (1) the melatonin group, treated with a single intravenous dose of melatonin solution containing 10 mg melatonin each, and (2) the control group, which was treated with 10 mL of the vehicle without melatonin. Changes in the TH at the level of the supra testicular artery (STA) were assessed by triplex ultrasonography just before (0 h) and at 0.5, 2, 7, 24, and 168 h after melatonin or vehicle administration. Doppler velocity parameters of peak systolic velocity (PSV; cm/s), end-diastolic velocity (EDV; cm/s), and time average maximum velocity (TAMAX; cm/s) were measured. Doppler indices (resistive index; RI and pulsatility index; PI), systole/diastole (S/D) ratio and total arterial blood flow volume (TABFV; ml/minute) were measured. Peripheral concentrations of FSH, LH, inhibin, melatonin, testosterone (T), estradiol (E2), and cortisol were measured just before injection (0 h) and at 0.5, 2, 7, and 24 h and daily up to day 7 post administration in both groups. Results revealed reductions in the RI values and increases in the TABFV in the melatonin group compared to the control one, especially 2 h after administration. Significant increases in concentrations of FSH, T, E2, and melatonin and decreases in cortisol and inhibin in the melatonin group compared to the control one. Plasma metabolomic analysis at 2 h indicated the up-regulation of L-glutamine, L-arginine, sorbitol, D-glucose, ascorbic acid, and ornithine and the down-regulation of D-xylose, D-arabitol, ribitol, and oleic acid in the melatonin versus the control group. In conclusion, acute administration of melatonin (10 mg IV) enhanced testicular artery blood flow and plasma reproductive hormones in the Shiba goat under heat-stress circumstances.

Intracranial arterial flow velocity mapping in quantitative time-of-flight MR angiography using deep machine learning

PurposeTo evaluate the application of deep machine learning (DML) to 3D quantitative time-of-flight (qTOF) magnetic resonance angiography (MRA) to measure blood flow velocity within the intracranial arteries. Materials and methodsIntracranial qTOF MRA was acquired in 15 subjects at 3 T. Blood flow velocity quantitation with qTOF MRA was done using a non-DML computer-vision procedure, and using convolutional DML neural networks. 3D phase contrast (PC) MRA was used as the comparator. Using PC velocity measures as the output target and qTOF two-echo source image data as inputs, DML neural networks were trained to predict component blood flow velocities. Total velocities and peak intracranial arterial blood flow velocities were computed from component velocities. ResultsCompared to non-DML image analysis, DML-based analysis of qTOF MRA image data improved agreement with PC for mean component velocity (intraclass correlation coefficient (ICC) = 0.966 versus 0.939), mean total velocity (ICC = 0.835 versus 0.723), and peak velocity (ICC = 0.816 versus 0.597), as well as narrowed the 95% Bland-Altman limits of agreement for mean component velocity ([−5.16, +4.31]cm/s versus [−6.86, +6.53]cm/s), mean total velocity ([−6.78,+3.59]cm/s versus [−9.39, +7.09]cm/s) and peak velocity ([−13.5,+10.2]cm/s versus [−21.3, +10.2]cm/s). Compared to non-DML analysis, DML image analysis reduced the root-mean-square deviation from PC velocity measures by 28%–36%, and shortened calculation times by 35-fold. ConclusionThe application of DML image analysis to intracranial qTOF MRA for velocity quantitation markedly shortened calculation times, substantially improved the agreement of component, total, and peak arterial blood flow velocities, and provided excellent agreement of hemodynamic measures with respect to 3D PC.

Lower cerebral arterial blood flow is associated with greater serum neurofilament light chain levels in multiple sclerosis patients

Background: Hypoperfusion, vascular pathology, and cardiovascular risk factors are associated with disease severity in multiple sclerosis (MS).1,2 In particular, the total cerebral arterial blood flow (CABF), measured as a sum of all arterial flow in the neck, was associated with the cognitive performance of MS patients.3&#x0D; Objective: To assess relationships between CABF and serum neurofilament light chain (sNfL), as neuronal damage biomarker with good prognostic value and treatment responsiveness.4 If the cerebrovascular changes are an independent pathophysiological factor in MS, a relationship should remain significant after controlling for common MS-based disease measures (i.e., T2 lesion volume and brain volume).&#x0D; Materials and methods: Total CABF was measured in 137 patients (86 clinically isolated syndrome (CIS)/relapsing-remitting (RR) and 51 progressive MS (PMS)) and 48 healthy controls (HCs) using Doppler ultrasound. sNfL was quantitated using a single molecule assay (Simoa). Three point zero T magnetic resonance imaging (MRI) examination allowed quantification of T2 lesion and whole-brain volume (WBV). Multiple linear regression models determined the sNfL associated with CABF after correction for demographic and MRI-derived variables.&#x0D; Results: After adjustment for age, sex and body mass index (BMI), total CABF remained statistically significant and model comparisons showed that CABF explained additional 2.6% of the sNfL variance (β=-0.167, p=0.044). (Table 1) CABF also remained significant in a step-wise regression model (β=0.18, p=0.034) upon the inclusion of T2 lesion burden and WBV effects. The explained sNfL variance improved from 17.4%, 22.7% with the presence of at least 2 CVD variable and 25.8% with both CVD and CABF predictors. Lastly, the disease-modifying therapy was not kept in the final model as an independent predictor of sNfL. Patients in the lowest CABF quartile (CABF≤761 mL/min) had significantly higher sNfL (34.6 pg/mL versus 23.9 pg/mL, adjusted-p=0.042) when compared to the highest quartile (CABF≥1130 mL/min).&#x0D; Conclusions: Lower CABF is associated with increased sNfL in MS patients, highlighting direct and independent relationship between cerebral hypoperfusion and axonal pathology. This relationship remained significant in the CIS/RRMS after adjusting for age, sex, and BMI effects.

Respiratory and heart rate dynamics during peripheral chemoreceptor deactivation compared to targeted sympathetic and sympathetic/parasympathetic (co-)activation.

The importance of peripheral chemoreceptors for cardiorespiratory neural control is known for decades. Pure oxygen inhalation deactivates chemoreceptors and increases parasympathetic outflow. However, the relationship between autonomic nervous system (ANS) activation and resulting respiratory as well as heart rate (HR) dynamics is still not fully understood. In young adults the impact of (1) 100% pure oxygen inhalation (hyperoxic cardiac chemoreflex sensitivity (CHRS) testing), (2) the cold face test (CFT) and (3) the cold pressor test (CPT) on heart rate variability (HRV), hemodynamics and respiratory rate was investigated in randomized order. Baseline ANS outflow was determined assessing respiratory sinus arrhythmia via deep breathing, baroreflex sensitivity and HRV. Baseline ANS outflow was normal in all participants (23±1years, 7 females, 3 males). Hyperoxic CHRS testing decreased HR (after 60±3 vs before 63±3min-1, p=0.004), while increasing total peripheral resistance (1053±87 vs 988±76dyne*s+m2/cm5, p=0.02) and mean arterial blood pressure (93±4 vs 91±4mmHg, p=0.02). HRV indicated increased parasympathetic outflow after hyperoxic CHRS testing accompanied by a decrease in respiratory rate (15±1vs 19±1min-1, p=0.001). In contrast, neither CFT nor CPT altered the respiratory rate (18±1 vs 18±2min-1, p=0.38 and 18±1 vs 18±1min-1, p=0.84, respectively). Changes in HR characteristics during deactivation of peripheral chemoreceptors but not during the CFT and CPT are related with a decrease in respiratory rate. This highlights the need of respiratory rate assessment when evaluating adaptations of cardiorespiratory chemoreceptor control.

Pulmonary arterial pruning is associated with CT-derived bronchiectasis progression in smokers

Loss of small pulmonary arteries measured as the ratio of blood vessel volume in arteries <5 mm2 in cross-section to total arterial blood vessel volume (BV5a/TBVa), with lower values indicating more pruning, was associated with 5-yr progressing CT-derived bronchiectasis in smokers (Odds Ratio (OR) [95% Confidence interval], 1.28 [1.07–1.53] per 5% lower BV5a/TBVa, P = 0.007). Corresponding results in smokers with COPD were: OR 1.45 [1.11–1.89] per 5% lower BV5a/TBVa, P = 0.007. The results support a vascular factor for structural progression of bronchiectasis.

Maternal hemodynamics and computerized cardiotocography during labor with epidural analgesia

PurposeTo analyze the mechanisms involved in the fetal heart rate (FHR) abnormalities after the epidural analgesia in labor.MethodsA prospective unblinded single-center observational study on 55 term singleton pregnant women with spontaneous labor. All women recruited underwent serial bedside measurements of the main hemodynamic parameters using a non-invasive ultrasound system (USCOM-1A). Total vascular resistances (TVR), heart rate (HR), stroke volume (SV), cardiac output (CO) and arterial blood pressure were measured before epidural administration (T0), after 5 min 5 (T1) from epidural bolus and at the end of the first stage of labor (T2). FHR was continuously recorded through computerized cardiotocography before and after the procedure.ResultsThe starting CO was significantly higher in a subgroup of women with low TVR than in women with high-TVR group. After the bolus of epidural analgesia in the low-TVR group there was a significant reduction in CO and then increased again at the end of the first stage, in the high-TVR group the CO increased insignificantly after the anesthesia bolus, while it increased significantly in the remaining part of the first stage of labor. On the other hand, CO was inversely correlated with the number of decelerations detected on cCTG in the 1 hour after the epidural bolus while the short-term variation was significantly lower in the group with high-TVR.ConclusionMaternal hemodynamic status at the onset of labor can make a difference in fetal response to the administration of epidural analgesia.

Morphological and ultrasonographic characterization of the three zones of supratesticular region of testicular artery in Assaf rams

To fully understand the histological, morphometrical and heamodynamic variations of different supratesticular artery regions, 20 mature and healthy Assaf rams were examined through ultrasound and morphological studies. The testicular artery images of the spermatic cord as shown by B-mode analysis indicated a tortuous pattern along its course toward the testis, although it tends to be less tortuous close to the inguinal ring. Doppler velocimetric values showed a progressive decline in flow velocity, in addition to pulsatility and vessel resistivity when entering the testis, where there were significant differences in the Doppler indices and velocities among the different regions. The peak systolic velocity, pulsatility index and resistive index were higher in the proximal supratesticular artery region, followed by middle and distal ones, while the end diastolic velocity was higher in the distal supratesticular region. The total arterial blood flow and total arterial blood flow rate reported a progressive and significant increase along the testicular cord until entering the testis. Histological examination revealed presence of vasa vasorum in the tunica adventitia, with their diameter is higher in the proximal supratesticular zone than middle and distal ones. Morphometrically, the thickness of the supratesticular artery wall showed a significant decline downward toward the testis; meanwhile, the outer arterial diameter and inner luminal diameter displayed a significant increase distally. The expression of alpha smooth muscle actin and vimentin was higher in the tunica media of the proximal supratesticular artery zone than in middle and distal ones.

Decreased Craniocervical CSF Flow in Patients with Normal Pressure Hydrocephalus: A Pilot Study.

Normal pressure hydrocephalus is characterized by systolic peaks of raised intracranial pressure, possibly due to a reduced compliance of the spinal CSF spaces. This concept of a reduced spinal CSF buffer function may be reflected by a low cervical CSF outflow from the cranium. The aim of this study was to investigate craniospinal CSF flow rates by phase-contrast MR imaging in patients with normal pressure hydrocephalus. A total of 42 participants were included in this prospective study, consisting of 3 study groups: 1) 10 patients with normal pressure hydrocephalus (mean age, 74 [SD, 6] years, with proved normal pressure hydrocephalus according to current scientific criteria); 2) eighteen age-matched healthy controls (mean age, 71 [SD, 5] years); and 3) fourteen young healthy controls (mean age, 21 [SD, 2] years, for investigation of age-related effects). Axial phase-contrast MR imaging was performed, and the maximal systolic CSF and total arterial blood flow rates were measured at the level of the upper second cervical vertebra and compared among all study groups (2-sample unpaired t test). The maximal systolic CSF flow rate was significantly decreased in patients with normal pressure hydrocephalus compared with age-matched and young healthy controls (53 [SD, 40] mL/m; 329 [SD, 175] mL/m; 472 [SD, 194] mL/m; each P < .01), whereas there were no significant differences with regard to maximal systolic arterial blood flow (1160 [SD, 404] mL/m; 1470 [SD, 381] mL/m; 1400 [SD, 254] mL/m; each P > .05). The reduced maximal systolic craniospinal CSF flow rate in patients with normal pressure hydrocephalus may be reflective of a reduced compliance of the spinal CSF spaces and an ineffective spinal CSF buffer function. Systolic craniospinal CSF flow rates are an easily obtainable MR imaging-based measure that may support the diagnosis of normal pressure hydrocephalus.

Association of pre-pregnancy body mass index and rate of weight gain during pregnancy with maternal indicators of cardiometabolic risk

Background/objectiveChanges in metabolism and extensive hemodynamic adjustments occur during normal pregnancy. The presence of maternal obesity imposes an overload to these physiological adaptations that may result in increased risk for the development of cardiometabolic complications during and after pregnancy. The aim of this study is to describe total cholesterol (TC), triglycerides (TG), glucose, and arterial blood pressure (BP) trajectories and to analyze the association of these cardiometabolic risk indicators during pregnancy with pre-pregnancy body mass index (pBMI) and monthly gestational weight gain (MGWG).Subjects/methodsA prospective cohort study of pregnant women was conducted in Mexico City. Monthly samples of blood were taken during clinical follow-up and biochemical and blood pressure were measured during each visit. Adjusted linear mixed-effect regression models were fit to describe the trajectories of these biomarkers during pregnancy and to analyze the association with pBMI and MGWG.ResultsSeven hundred and twenty women were included of which 16.6% had pre-gestational obesity, 33.2% had pre-gestational overweight, 45.8% had normal pBMI and 4.4% had pre-gestational underweight. Women with pre-gestational obesity had higher lipids concentrations in the beginning of pregnancy (TC: hat beta = 33.08, p = 0.010; TG: hat beta = 31.29, p = <0.001) but the concentrations increased less than in women with normal pBMI (TC: hat beta = −14.18, p = 0.001; TG: hat beta = −5.42, p < 0.001). By the end of pregnancy, women with pre-gestational obesity had lower concentrations of lipids than women with normal pBMI. By contrast, women with pre-gestational obesity had higher glucose concentrations and higher BP levels than women with normal pBMI over pregnancy.ConclusionspBMI is differentially associated with longitudinal trajectories of maternal biochemical markers of cardiometabolic risk. MGWG did not significantly affect the biochemical indicators or BP trajectories. Our results suggest that pBMI is more relevant to predicting adverse cardiometabolic markers trajectories during pregnancy than MGWG.

Real-time visualization of renal microperfusion using laser speckle contrast imaging.

.Significance: Intraoperative parameters of renal cortical microperfusion (RCM) have been associated with postoperative ischemia/reperfusion injury. Laser speckle contrast imaging (LSCI) could provide valuable information in this regard with the advantage over the current standard of care of being a non-contact and full-field imaging technique.Aim: Our study aims to validate the use of LSCI for the visualization of RCM on ex vivo perfused human-sized porcine kidneys in various models of hemodynamic changes.Approach: A comparison was made between three renal perfusion measures: LSCI, the total arterial renal blood flow (RBF), and sidestream dark-field (SDF) imaging in different settings of ischemia/reperfusion.Results: LSCI showed a good correlation with RBF for the reperfusion experiment (; ) and short- and long-lasting local ischemia (; and ; , respectively). The correlation decreased for low flow situations due to RBF redistribution. The correlation between LSCI and SDF (; ) showed superiority over RBF (; ).Conclusions: LSCI is capable of imaging RCM with high spatial and temporal resolutions. It can instantaneously detect local perfusion deficits, which is not possible with the current standard of care. Further development of LSCI in transplant surgery could help with clinical decision making.

Intraoperative evaluation of the hepatic artery blood flow during pancreatoduodenectomy (HEPARFLOW Study)

Introduction: During pancreatoduodenectomy division of the gastroduodenal artery can disturb liver blood supply and result in liver ischemia in patients with celiac axis stenosis (CAS). We aimed to assess liver blood supply during pancreatoduodenectomy and the associated risk for ischemia. Methods: This prospective observational study included patients undergoing partial or total pancreatoduodenectomy. Blood flow in the proper hepatic, gastroduodenal, additional arteries and in the portal vein was measured using Doppler flowmetry. Preoperative computed tomography was evaluated with focus on anatomic variations and CAS. Liver perfusion and function failure were recorded based on laboratory parameters. Other complications were also assessed. Results: Between 04/2018 and 01/2019, 100 patients undergoing pancreatoduodenectomy were analyzed. Proper hepatic artery flow was 190.7±156.3 ml/min before, 187.4±158.8 ml/min after division of the GDA (P=0.431) and had increased by 60% to 305.6±224.6 ml/min at the end of surgery (P< 0.001). In the presence of replaced or accessory hepatic arteries (n=23) the total arterial blood flow per cubic centimeter of liver parenchyma was significantly higher compared to standard vascular anatomy (n=75) (0.29±0.13 ml/(min.cm3) versus 0.23±0.13 ml/(min.cm3); P=0.044). The presence of CAS (n=35) was associated with lower total flow (0.20±0.11 ml/(min.cm3) versus 0.27±0.14 ml/(min.cm3); P=0.031) and with a trend towards increased severe complications (25.8% versus 10.9%; P=0.07). Conclusion: This is the first study performing systematic intraoperative flow measurement to assess liver blood supply during pancreatoduodenectomy. CAS is a risk factor for reduced hepatic arterial flow and increased morbidity. Additional hepatic arteries increase total arterial flow and may be protective.

Simulations of blood pressure and identification of atrial fibrillation and arterial stiffness using an extended Kalman filter with oscillometric pulsation measurements

Background and ObjectiveThe accuracy of systolic and diastolic blood pressure levels from oscillometric devices is difficult to assess for patients with atrial fibrillation and arterial stiffness; in such cases, changes in these levels from heartbeat to heartbeat can only be known if the actual total waveform during a test can be observed. Variation in these levels affects the accuracy of the algorithms in oscillometric devices where precision is of paramount importance according to the American College of Cardiology and the American Heart Association. Recently issued guidelines lowered the definition of high blood pressure; approximately three-quarters of men over 65 years of age meet the criterion and are diagnosed as hypertensive. A review in 2019 reported that atrial fibrillation affects approximately 3% of the general population in the U.S. and is twice as common in hypertensive patients. The actual shape and details of the arterial blood pressure waveform not only reveal variations in rhythm and in systolic and diastolic levels but has also proven to be valuable in the diagnosis of arterial stiffness and atrial fibrillation which are vital to determining the physiological status of a patient's cardiovascular system. This research pertains to the identification of a patient's total arterial blood pressure waveform using only the measured pulsations in the cuff of an oscillometric device. MethodEmpirically formulated hypothetical arterial blood pressure waveforms were simulated and assumed to be unknown. Oscillometric pulsations corresponding to these simulated unknown waveforms were used as input to a new model-based extended Kalman filter algorithm for identifying the levels, shape and features of the unknown waveforms. ResultsSimulations with hypothetical waveforms with varying systolic and diastolic levels and with variations in heartbeat rhythm associated arterial fibrillation and stiff arteries, demonstrate potential arterial pressure estimate accuracies of 1.5 mmHg with standard deviations on the order of 0.1 mmHg; in addition, variations in heartbeat rhythm were observed and degrees of arterial stiffness identified and quantified. ConclusionsComputational analysis of the oscillometric cuff pulsations with the extended Kalman filter can be used to detect variations in heartbeat rhythm and blood pressure levels associated atrial fibrillation, quantify arterial stiffness, and provide noninvasive continuous blood pressure monitoring without the need for electrocardiogram or photoplethysmography sensors.

Resuscitative endovascular balloon occlusion of the aorta for thoracic trauma in the setting of platelet dysfunction: A translational swine study.

In patients with noncompressible torso hemorrhage, antiplatelet medications may lead to worse outcomes. Resuscitative endovascular balloon occlusion of the aorta (REBOA) may potentially stabilize these patients, but currently, major thoracic bleeding is a contraindication. The goal of this study was to determine if REBOA use for shock with major thoracic bleeding has worse outcomes in the setting of platelet dysfunction (PD). Forty-one male Yorkshire swine (60-80 kg) underwent a 30% hemorrhage and then were randomized to three thoracic injuries, with and without zone 1 REBOA occlusion: pulmonary parenchymal injury (PI), thoracic venous injury (VI), or subclavian artery injury (AI). All animals were given aspirin to produce PD. Following hemorrhage, thoracic injuries were induced (T0) and allowed to bleed freely. Resuscitative endovascular balloon occlusion of the aorta groups had zone 1 occlusion, with deflation at T30. All groups received whole blood resuscitation at T30 and were euthanized at T90. Survival, total blood loss, hemodynamics, and arterial blood gas parameters were analyzed. The PD-VI-REBOA group had 87.5% survival where PD-VI survival was 28.6%. No difference in survival was seen in the PI or AI groups. The PD-VI-REBOA group had total blood loss of 575.0 ± 339.1 mL, which was less than the PD-VI group (1,086.0 ± 532.1 mL). There was no difference in total thoracic blood loss in the PI and AI groups with the addition of REBOA. All groups showed an equivalent decrease in HCO3 and base excess and increase in lactate at the end of the 30-minute prehospital phase. In this study, zone 1 REBOA improved survival and decreased blood loss with major VI, where no differences were seen in parenchymal and subclavian artery injuries. For thoracic bleeding without surgical capability, outcomes may be improved with REBOA, and these findings challenge current guidelines stating the contraindication of REBOA use in this setting.

Repeatability and Reproducibility of Total Retinal Blood Flow Measurements Using Bi-Directional Doppler OCT.

PurposeTo investigate the repeatability and reproducibility of total retinal blood flow measurements using a custom-built dual-beam bidirectional Doppler optical coherence tomography (OCT) system in healthy subjects.MethodsRepeatability and reproducibility were analyzed in 10 and 34 healthy subjects, respectively. For repeatability, measurements were taken twice within 30 minutes, for reproducibility, twice within two to five weeks. Two analysis approaches were compared for calculation of absolute blood velocities: a previously published approach resulting in values for total arterial (QA,abs) and total venous blood flow (QV,abs) and a novel approach taking into account that there is a fixed relation between the phase shift in the two OCT channels (QA,new, QV,new). Repeatability and reproducibility were quantified using intraclass correlation coefficients (ICCs).ResultsFor QA,abs and QV,abs, ICC values between 0.78 and 0.84 were obtained. QA,new and QV,new values revealed better repeatability and reproducibility as compared to the convential appoach. Repeatability ICCs for QA,new and QV,new were between 0.91 and 0.93, and reproducibility ICCs were between 0.87 and 0.91 indicating excellent reproducibility. Good agreement was observed between total retinal blood flow values as measured from retinal arteries and retinal veins.ConclusionsMeasurement of total retinal blood flow using dual-beam Doppler OCT shows excellent reproducibility, which can further be improved by using a novel algorithm for calculating blood velocities in retinal vessels.Translational RelevanceOur data indicate that dual-beam Doppler OCT can be used for longitudinal studies. Hence, quantitative retinal blood flow may be established as a biomarker for progression vascular eye diseases.

The Effects of Concurrent Training Combining Both Resistance Exercise and High-Intensity Interval Training or Moderate-Intensity Continuous Training on Metabolic Syndrome.

To date, there are several knowledge gaps on how to properly prescribe concurrent training to achieve the best dose-response, especially regarding the optimal intensity or volume of the aerobic component. Thus, the objective of this study is to analyze the effects of different aerobic exercise modes and intensities [i.e. aerobic high-intensity interval training (HIIT) versus moderate-intensity continuous aerobic training (MICT) combined with a resistance training (RT) program] on metabolic outcomes in participants with metabolic syndrome (MetS). Thirty-nine men and women (67.0 ± 6.7 years) volunteered to a 12-weeks exercise intervention (3 week–1, 50 min/session) and were randomly assigned to one of three groups: (a) RT plus MICT (RT+MICT) (2 males; 11 females); (b) RT plus HIIT (RT+HIIT) (4 males; 9 females); and (c) control group (CON) – without formal exercise (4 males; 9 females). Intensity was established between 60 and 70% of maximum heart rate (HRmax) in RT+MICT and ranged from 55–65% to 80–90% HRmax in the RT+HIIT group. Dependent outcomes included morphological, metabolic and hemodynamic variables. Both training groups improved waist circumference (RT+MICT: P = 0.019; RT+HIIT: P = 0.003), but not body weight, fat mass or fat-free mass (P ≥ 0.114). RT+HIIT group improved fasting glucose (P = 0.014), low density lipoprotein [LDL (P = 0.022)], insulin (P = 0.034) and homeostatic model assessment (P = 0.028). RT+MICT group reduced triglycerides (P = 0.053). Both exercise interventions did not change high sensitivity C-reactive protein, glycated hemoglobin, high density lipoprotein and total cholesterol, systolic, diastolic or mean arterial blood pressure (P ≥ 0.05). The CON group reduced the LDL (P = 0.031). This trial suggests that short-term exercise mode and intensity may differently impact the metabolic profile of individuals with MetS. Further, our data suggests that both concurrent trainings promote important cardiometabolic gains, particularly in the RT+HIIT. Nonetheless, due to the small-to-moderate effect size and the short-term intervention length, our data suggests that the intervention length also has an important modulating role in these benefits in older adults with MetS. Therefore, more research is needed to confirm our results using longer exercise interventions and larger groups.

Hemodynamic response to low-flow acute supplemental oxygen in idiopathic pulmonary fibrosis and elderly healthy subjects

BackgroundHemodynamic response to supplemental oxygen in idiopathic pulmonary fibrosis (IPF) is still not well known. ObjectiveTo determine and compare the effect of low-flow acute supplemental oxygen on the hemodynamics of IPF patients and matched healthy subjects. MethodsDescriptive and comparative study in 20 IPF-patients and 19 Control-subjects, (60-80 years old) breathing ambient air followed by acute nasal low-flow (3 L/min) supplemental oxygen. Non-invasive methods were used during the supine position to evaluate oxygen saturation, heart rate, stroke volume index, cardiac output index, total peripheral resistance and arterial blood pressure. ResultsBreathing ambient air, IPF (vs. Control) presented lower values in stroke volume index (38.7 [29.4–43.2] vs. 45.4 [38.4–50.9] mL•kg-1•m2; p=0.009) and cardiac output index (2.484 [2.268 – 2.946] vs. 2.857 [2.628 – 3.054] L•min−1•m−2; p=0.028), with higher total peripheral resistance (1644 [1559–2076] vs. 1505 [1366–1784] dyne•s•cm−5; p=0.017). During supplemental oxygen (vs. ambient air), both groups increased oxygen saturation above 94% (p<0.001) while heart rate decreased about 6 to 8% (p<0.001); stroke volume index increased around 7% in the Control-group (p=0.004) but only 1% in the IPF-group (p=0.017). In addition, IPF showed increments in total peripheral resistance (1644 [1559–2076] vs. 1706 [1554–2278] dyne•s•cm−5; p=0.017) with subsequent decrements in cardiac output index (2.484 [2.268 – 2.946] vs. 2.362 [2.139 – 2.664] L•min−1•m−2; p<0.001). ConclusionLow-flow acute supplemental oxygen in IPF causes a meaningful decrement in cardiac output due to greater reduction in heart rate and increment in total peripheral resistance than matched healthy subjects. Knowing the hemodynamic profile of IPF patients may be helpful in determining their management with supplemental oxygen.

Examination of jackass (Equus asinus) accessory sex glands by B-mode ultrasound and of testicular artery blood flow by colour pulsed-wave Doppler ultrasound: Correlations with semen production.

The accessory sex glands play a major role in the production of seminal plasma, and testicular artery blood flow seems to strongly influence testicular function. However, very little ultrasound imaging of these organs has been undertaken in donkeys. The present work reports the results of such examinations in five jackasses along the year. The accessory glands were inspected by B-mode ultrasound while the testicular artery blood flow was assessed by colour pulsed-wave Doppler ultrasound. The testicular artery was examined at pampiniform plexus (PPT), supratesticular area (ST) and capsular artery (CA). Values were recorded for the total arterial blood flow (TABF), peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI) and time average maximum velocity (TAMV). Semen was obtained and assessed for sperm concentration, viability, abnormalities and motility using a CASA system. The bulbourethral glands, prostate and ductus deferens ampullae were relatively larger than in the stallion. Bulbourethral glands and ampullae sizes were inversely correlated with sperm motility. An reduction in blood flow between the level the PPP and the CA was observed, helping to reduce testis temperature and oxygen pressure. Blood flow at the CA showed the strongest correlation with semen production. PI and RI were positively correlated with the CASA motility variable STR (p=.02, p=.06) and sperm viability (p=.01), while sperm concentration (p=.05) correlated inversely with PSV, EDV, TAMV and TABF. EDV also correlated negatively with the CASA variables VSL, LIN, STR and VAP (p≤.05). PI and RI were also negatively correlated with testis length (p=.0093, p=-.0438).