Peripheral Venous Pressure Research Articles

Institutional transition from invasive to non-invasive imaging in children with univentricular heart defects: safety and cost savings.

Patients with univentricular heart defects require lifelong imaging surveillance. Recent advances in non-invasive imaging have enabled replacing these patients' routine catheterisation. Our objective was to describe the safety and cost savings of transition of a tertiary care children's hospital from routine invasive to routine non-invasive imaging of low-risk patients with univentricular heart defects. This single-centre cohort study consists of 1) a retrospective analysis of the transition from cardiac catheterisation (n = 21) to CT angiography (n = 20) before bidirectional Glenn operation and 2) a prospective study (n = 89) describing cardiac magnetic resonance before and after the total cavopulmonary connection in low-risk patients with univentricular heart defects. Pre-Glenn: The total length of CT angiography was markedly shorter compared to the catheterisation: 30 min (range: 20-60) and 125 min (range: 70-220), respectively (p < 0.001). Catheterisation used more iodine contrast agents than CT angiography, 19 ± 3.9 ml, and 10 ± 2.4 ml, respectively (p < 0.001). Controlled ventilation was used for all catheterised and 3 (15%) CT angiography patients (p < 0.001). No complications occurred during CT angiography, while they emerged in 19% (4/21) catheterisation cases (p < 0.001). CT angiography and catheterisation showed no significant difference in the radiation exposure. Pre-/post-total cavopulmonary connection: All cardiac magnetic resonance studies were successful, and no complications occurred. In 60% of the cardiac magnetic resonance (53/89), no sedation was performed, and peripheral venous pressure was measured in all cases. Cost analysis suggests that moving to non-invasive imaging yielded cost savings of at least €2500-4000 per patient. Transition from routine invasive to routine non-invasive pre-and post-operative imaging is safely achievable with cost savings.

Sympathetic vasomotor outflow during low-intensity leg cycling in healthy older males.

What is the central question of this study? Sympathetic vasomotor outflow is reduced during low-intensity dynamic leg exercise in younger individuals: does ageing influence the sympathoinhibitory effect during low-intensity leg cycling? What is the main finding and its importance? Muscle sympathetic nerve activity during low-intensity cycling decreased in older males, as seen in young males. It is possible that cardiopulmonary baroreflex-mediated inhibition of sympathetic vasomotor outflow during dynamic leg exercise is preserved in healthy older males. Muscle sympathetic nerve activity (MSNA) is reduced during low-intensity dynamic leg exercise in young males. It is suggested that this inhibition is mediated by loading of the cardiopulmonary baroreceptors. The purpose of this study was to clarify the impact of age on MSNA during dynamic leg exercise. Nine younger males (YM, mean±SD, 20±1years) and nine older males (OM, 72±3years) completed the study. The subjects performed two 4-min cycling exercises at 10% of their heart rate reserve using a cycle ergometer in a semirecumbent position (MSNA and estimated central venous pressure (eCVP) trials). MSNA was recorded via microneurography of the left radial nerve. The CVP was estimated based on peripheral venous pressure, which was monitored using a cannula in the right large antecubital vein. The magnitude of the increase in mean arterial blood pressure during leg cycling was larger in OM (+9.3±5.5mmHg) compared with YM (+2.8±4.7mmHg). MSNA burst frequency was decreased during cycling in both YM (-8.1±3.8bursts/min) and OM (-10.6±3.3bursts/min), but no significant difference was found between the two groups. The eCVP increased during exercise in both groups, and there was no difference in the changes in eCVP between YM (+1.1±0.4mmHg) and OM (+1.2±0.7mmHg). These data indicate that inhibition of sympathetic vasomotor outflow during low-intensity cycling appears in OM as seen in YM. It is possible that the muscle pump-induced loading of the cardiopulmonary baroreflex is preserved during cycling in healthy older males.

Critical Information from High Fidelity Arterial and Venous Pressure Waveforms During Anesthesia and Hemorrhage.

Peripheral venous pressure (PVP) waveform analysis is a novel, minimally invasive, and inexpensive method of measuring intravascular volume changes. A porcine cohort was studied to determine how venous and arterial pressure waveforms change due to inhaled and infused anesthetics and acute hemorrhage. Venous and arterial pressure waveforms were continuously collected, while each pig was under general anesthesia, by inserting Millar catheters into a neighboring peripheral artery and vein. The anesthetic was varied from inhaled to infused, then the pig underwent a controlled hemorrhage. Pearson correlation coefficients between the power of the venous and arterial pressure waveforms at each pig's heart rate frequency were calculated for each variation in the anesthetic, as well as before and after hemorrhage. An analysis of variance (ANOVA) test was computed to determine the significance in changes of the venous pressure waveform means caused by each variation. The Pearson correlation coefficients between venous and arterial waveforms decreased as anesthetic dosage increased. In an opposing fashion, the correlation coefficients increased as hemorrhage occurred. Anesthetics and hemorrhage alter venous pressure waveforms in distinctly different ways, making it critical for researchers and clinicians to consider these confounding variables when utilizing pressure waveforms. Further work needs to be done to determine how best to integrate PVP waveforms into clinical decision-making.

Association of peripheral venous pressure with adverse post-discharge outcomes in patients with acute heart failure: a prospective cohort study.

Congestion is the major cause of hospitalization for heart failure (HF). Traditional bedside assessment of congestion is limited by insufficient accuracy. Peripheral venous pressure (PVP) has recently been shown to accurately predict central venous congestion. We examined the association between PVP before discharge and post-discharge outcomes in hospitalized patients with acute HF. Bedside PVP measurement at the forearm vein and traditional clinical examination were performed in 239 patients. The association with the primary composite endpoint of cardiovascular death or HF hospitalization and the incremental prognostic value beyond the established HF risk score was examined. The PVP correlated with peripheral oedema, jugular venous pressure, and inferior vena cava diameter, but not with brain-type natriuretic peptide. The 1-year incidence of the primary outcome measure in the first, second, and third tertiles of PVP was 21.4, 29.9, and 40.7%, respectively (log-rank P = 0.017). The adjusted hazard ratio of PVP per 1 mmHg increase for the 1-year outcome was 1.08 [95% confidence interval (1.03-1.14), P = 0.004]. When added onto the Meta-Analysis Global Group in Chronic HF risk score, PVP significantly increased the area under the receiver-operating characteristic curve for predicting the outcome [from 0.63 (0.56-0.71) to 0.70 (0.62-0.77), P = 0.02), while traditional assessments did not. The addition of PVP also yielded significant net reclassification improvement [0.46 (0.19-0.74), P < 0.001]. The PVP at discharge correlated with prognosis. The results warrant further investigation to evaluate the clinical application of PVP measurement in the care of HF. UMIN000034279.

Jugular Venous Pressure Measurement Is Accurate When Performed By Attending Physicians On Internal Medicine Wards

<h3>Introduction</h3> Jugular venous pressure (JVP) is a widely used estimate of central venous pressure (CVP). It is unclear how accurate JVP measurement is by physicians in different stages of clinical practice. We investigated the accuracy of JVP measurement across different levels of medical training by comparing JVP measurements to the peripheral venous pressure (PVP) measurement, which has been shown to have a high degree of correlation to CVP measurements. <h3>Hypothesis</h3> JVP will be better correlated with CVP when measured by physicians of higher level of clinical training. <h3>Methods</h3> A prospective, cross-sectional study in which 82 participants (13 third or fourth-year medical students, 26 interns, 21 residents, and 22 attending internal medicine physicians) measured JVP in patients admitted for acute decompensated heart failure (ADHF) to the general medicine ward. JVP measurements were compared to the PVP measured from a peripheral intravenous catheter by standard technique. <h3>Results</h3> Forty-five patients were enrolled with a mean age of 69±14 years, mean body mass index (BMI) of 31±9 kg/m², mean ejection fraction (EF) of 47±20%, and mean B-type natriuretic peptide (BNP) of 1242±1161 pg/ml. Mean JVP was 8.6 (4-18) cmH₂O for medical students, 8.7 (4-16) cmH₂O for interns, 9.1 (5-20) cmH₂O for residents, and 9.2 (4-15) cmH₂O for attending physicians. Mean PVP was 8.7 (1-20) mmHg. The JVP and CVP were found to have a moderate correlation (r=0.42, p=0.005) for attending physicians and a low correlation for medical students or residents. High-degree correlation among attending physicians was noted in patients with EF < 50% (r=0.60, p=0.009), BMI < 30 (r=0.55, p=0.008) and BNP > 1000 (r=0.56, p=0.01). <h3>Conclusions</h3> JVP is a reliable estimation of volume status in those admitted with ADHF when examined by an attending-level internal medicine physician, specifically in patients with a low BMI, low EF, and a high BNP.

Abstract MP78: Heart Failure And The Subsequent Risk Of Lymphedema In The Community

Background: Lymphedema, abnormal lymphatic fluid accumulation in tissues, results in serious complications such as ulceration and reduces quality of life. Cancer treatment, through damage to lymph nodes and lymphatic vessels, is recognized as the main risk factor of lymphedema. However, understanding other risk factors is crucial for the prevention of lymphedema since there is no established curative treatment. Heart failure (HF) is considered an emerging risk factor for lymphedema through increased central and peripheral venous pressure, but the association of HF with incident lymphedema has not been systematically studied. Methods: In the Atherosclerosis Risk in Communities study, we included 9,895 individuals without prevalent lymphedema and cancer at visit 4 (1996-98) (n=9362 with no HF and n=533 with HF). Lymphedema was defined as two outpatient encounters (at least a week apart) or inpatient diagnoses through 2015 (ICD-9: 457.1 and ICD-10: I89.0). Participants without prevalent HF were categorized into two groups according to NT-proBNP, a marker of cardiac volume overload (&gt;125 vs. ≤125 pg/mL [reference]), to acknowledge potential contribution of subclinical cardiac overload. Results: During a median follow-up of 17.7 (IQI 14.1-18.7) years, 149 participants developed lymphedema. 15-y cumulative incidence was higher in participants with HF and no HF with elevated NT-proBNP than those with no HF and non-elevated NT-proBNP (5.2% vs. 2.0% vs. 0.7%, respectively) ( Figure ). After accounting for potential confounders (e.g., body mass index, blood pressure, diabetes), the associations remained consistent (hazard ratios: 3.07 [95% CI 1.86, 5.08] for HF and 1.95 [1.33, 2.87] for no HF with elevated NT-proBNP). Results were consistent when using HF as a time-varying variable and censoring incident cancer. Conclusions: HF and subclinical elevation of NT-proBNP were associated with incident lymphedema, supporting the contribution of HF to the development of lymphedema.

Peripheral Venous Pressure-Assisted Exercise Stress Echocardiography in the Evaluation of Pulmonary Hypertension During Exercise in Patients With Suspected Heart Failure With Preserved Ejection Fraction.

Identification of elevated pulmonary artery (PA) pressures during exercise may provide diagnostic, prognostic, and therapeutic implications in heart failure with preserved ejection fraction. Although widely performed, exercise stress echocardiography may underestimate true PA pressures due to the difficulty in estimating right atrial pressure (RAP) during exercise. We hypothesized that peripheral venous pressure (PVP) could allow for reliable estimation of RAP, and thus PA pressures during exercise stress echocardiography. In protocol 1, we investigated the accuracy of PVP compared with simultaneously measured RAP at rest and during exercise right heart catheterization in 19 subjects. In protocol 2, we examined whether the addition of PVP to Doppler exercise echocardiography (tricuspid regurgitant velocity) would increase the ability to identify exercise-induced pulmonary hypertension compared with inferior vena cava-based RAP estimation in 60 patients with dyspnea. In protocol 1, PVP was strongly correlated with simultaneously measured RAP at rest and during exercise (r=0.77 and 0.90), with little overestimation of invasively measured RAP (bias 3.4 mm Hg at rest and 1.7 mm Hg during exercise). In protocol 2, PVP increased dramatically during exercise echocardiography (14±5 mm Hg) while an increase in inferior vena cava-based RAP was modest (6±4 mm Hg). Exercise PA pressures calculated from PVP and tricuspid regurgitant velocity were significantly higher than those estimated from inferior vena cava and the use of PVP increased the proportion of patients with exercise-induced pulmonary hypertension from 40% to 68%. PVP may prevent underestimation of PA pressures during exercise echocardiography and could be a preferred approach to identify exercise-induced pulmonary hypertension in patients with suspected heart failure with preserved ejection fraction.

Mechanical support for the failing single ventricle after Fontan

Mechanical support for the failing single ventricle after Fontan

Peripheral Venous Pressure Measurements to Evaluate Congestion in Heart Failure

Accurate bedside assessment of congestion in the management of patients with heart failure remains challenging. As a continuous conduit of circulating fluid, systemic congestion represented by high right atrial pressure (RAP) may be reflected by peripheral venous pressure (PVP). We evaluated the reliability of PVP measurements for assessing congestion beyond conventional clinical assessments. We performed conventional congestion assessments and PVP measurements in 95 patients undergoing pulmonary artery catheterization. PVP was measured via the 22-gauge peripheral venous access placed in the upper extremity. The median RAP and PVP was 7 (interquartile range [IQR]: 5-11) mmHg and 9 (IQR: 7-12) mmHg, respectively, with a mean bias of 1.8 ± 2.6 mmHg. PVP exhibited a strong linear correlation with RAP (Spearman R = 0.81; P < 0.001). PVP demonstrated greater discriminatory power for both RAP ≤ 8 mmHg (area under the curve [AUC]: 0.91 [95% confidence interval: 0.85-0.97]; sensitivity: 75%; specificity: 87%) and RAP > 12 mmHg (AUC: 0.98 [0.95-1.00]; sensitivity: 88%; specificity: 95%) than edema, jugular venous pressure, pulmonary congestion on chest radiograph, B-type natriuretic peptide levels, and inferior vena cava diameter. PVP measured via peripheral venous access strongly correlates with invasively obtained RAP. PVP measurements may improve current bedside assessments of congestion.

Exercise Intolerance, Benefits, and Prescription for People Living With a Fontan Circulation: The Fontan Fitness Intervention Trial (F-FIT)-Rationale and Design.

Background: Despite developments in surgical techniques and medical care, people with a Fontan circulation still experience long-term complications; non-invasive therapies to optimize the circulation have not been established. Exercise intolerance affects the majority of the population and is associated with worse prognosis. Historically, people living with a Fontan circulation were advised to avoid physical activity, but a small number of heterogenous, predominantly uncontrolled studies have shown that exercise training is safe—and for unique reasons, may even be of heightened importance in the setting of Fontan physiology. The mechanisms underlying improvements in aerobic exercise capacity and the effects of exercise training on circulatory and end-organ function remain incompletely understood. Furthermore, the optimal methods of exercise prescription are poorly characterized. This highlights the need for large, well-designed, multi-center, randomized, controlled trials.Aims and Methods: The Fontan Fitness Intervention Trial (F-FIT)—a phase III clinical trial—aims to optimize exercise prescription and delivery in people with a Fontan circulation. In this multi-center, randomized, controlled study, eligible Fontan participants will be randomized to either a 4-month supervised aerobic and resistance exercise training program of moderate-to-vigorous intensity followed by an 8-month maintenance phase; or usual care (control group). Adolescent and adult (≥16 years) Fontan participants will be randomized to either traditional face-to-face exercise training, telehealth exercise training, or usual care in a three-arm trial with an allocation of 2:2:1 (traditional:telehealth:control). Children (<16 years) will be randomized to either a physical activity and exercise program of moderate-to-vigorous intensity or usual care in a two-arm trial with a 1:1 allocation. The primary outcome is a change in aerobic exercise capacity (peak oxygen uptake) at 4-months. Secondary outcomes include safety, and changes in cardiopulmonary exercise testing measures, peripheral venous pressure, respiratory muscle and lung function, body composition, liver stiffness, neuropsychological and neurocognitive function, physical activity levels, dietary and nutritional status, vascular function, neurohormonal activation, metabolites, cardiac function, quality of life, musculoskeletal fitness, and health care utilization. Outcome measures will be assessed at baseline, 4-months, and 12-months. This manuscript will describe the pathophysiology of exercise intolerance in the Fontan circulation and the rationale and protocol for the F-FIT.

Abstract 11838: Isosorbide Dinitrate Effect May Improve Exercise Tolerance, Venous Pressure and Liver Stiffness in Patients With Fontan Circulation (The NEET Clinical Trial)

Introduction: After the Fontan operation, decreased venous capacitance (venoconstriction) and elevated central venous pressure may result in worse clinical outcomes, worse exercise capacity, and increased liver stiffness. This pilot study evaluated the acute effect of isosorbide dinitrate (ISDN), a venodilator, on exercise capacity, peripheral venous pressure (PVP), and liver stiffness in patients with Fontan circulation. Methods: In this prospective single-arm trial, 15 individuals with Fontan circulation were evaluated at baseline and after four weeks of treatment with ISDN. Cardiopulmonary exercise testing was performed to assess exercise tolerance, with a primary outcome of peak oxygen consumption (peak VO 2 ). The secondary outcome included VO 2 at the anaerobic threshold (AT VO 2 ), PVP at rest and peak exercise and liver stiffness measured by ultrasound prior to the exercise test. Repeated measure t-test was used to test for differences in outcomes in response to ISDN. Results: The mean age was 23.5 ± 9.2 years (range 11.2-30.6 years), and 10/15 (67%) were male. There was no statistically significant change in peak VO 2 from baseline (1401±428 to 1428±436 ml/min, p=0.128), but there was an improvement in AT VO 2 (1087 ± 313 to 1115 ±302 mL/min, p= 0.03). Treatment with ISDN was associated with lower peak exercise PVP (22.5 ±4.5 to 20.6 ± 2.99 mmHg, p=0.015) without a notable difference in the resting PVP (p=0.357). There was a trend towards lower liver stiffness with ISDN (2.3 ± 0.4 to 2.1 ± 0.5 m/s, p=0.079). Of the patients completing the trial, mild headache was common (67%), but there were no major adverse events. Conclusions: Treatment with ISDN for 4 weeks is well-tolerated except for headache and appears safe in patients with a Fontan circulation. ISDN therapy was associated with improvements in certain exercise and hemodynamic parameters as well as a trend towards lowering liver stiffness. Larger studies will be necessary to validate these physiologic findings and further evaluate the effects of nitrates on meaningful clinical outcomes.

Correlation of exercise-induced peripheral venous hypertension with exercise intolerance in patients with Fontan circulation.

Owing to the absence of a sub-pulmonary ventricle, the central venous pressure rises in patients with Fontan circulation. During exercise, central venous pressure may rise further to increase the systemic ventricular preload and cardiac output. We performed a single-centre prospective trial of cardiopulmonary exercise test while monitoring peripheral venous pressure which strongly correlates with central venous pressure. The objective of this study was to test the hypothesis that peripheral venous pressure at peak exercise inversely correlates with exercise capacity in patients with Fontan circulation. Seventeen patients following Fontan operation performed cardiopulmonary exercise test while monitoring peripheral venous pressure. Peak oxygen uptake, heart rate reserve, peak oxygen pulse (divided by body surface area), and peripheral venous pressure at peak exercise were measured. Correlations of peripheral venous pressure at peak exercise with the peak oxygen uptake, heart rate reserve, and peak oxygen pulse were evaluated. The peripheral venous pressure at peak exercise inversely correlated with the peak oxygen uptake (R = -0.66, p < 0.01), heart rate reserve (R = -0.6, p < 0.05), and peak oxygen pulse (R = -0.48, p < 0.05). Exercise-induced peripheral venous hypertension correlates with exercise intolerance in patients with Fontan circulation. Peak oxygen uptake is a useful index for evaluating the status of congestion in the daily life of patients with Fontan circulation.

Prospective Cohort Study Assessing the Use of Peripheral Saphenous Venous Pressure Monitoring as a Marker of the Transcaval Venous Pressure Gradient in Liver Transplant Surgery.

Assessment of the transcaval venous pressure gradient, the central venous to inferior vena caval pressure, assists anesthetists and surgeons in management of liver transplant recipients. Traditionally, this entails insertion of a femoral central line with increased patient risk and health care cost. Here, we assessed the ability of a saphenous vein cannula to act as a surrogate for the femoral central line as a means to assess the transcaval pressure gradient in a safer and less invasive manner. A prospective cohort of 22 patients undergoing liver transplant underwent saphenous vein cannulation in addition to insertion of a femoral and internal jugular central venous catheter. Data were collected throughout each phase of surgery to assess the central, femoral, and saphenous vein pressures; results of a range of relevant physiological and ventilatory data were also collected. The primary outcome, the correlation between saphenous and femoral venous pressure throughout surgery, was acceptable (r2 = 0.491, P < .001). During the anhepatic phase of surgery, this correlation improved (r2 = 0.912, P < .001). The correlation between the femoral to central venous pressure and saphenous to central venous pressure gradients was also reasonable throughout surgery (r2 = 0.386, P < .001), and this correlation was significantly stronger during the anhepatic phase (r2 = 0.935, P < .001). Saphenous venous pressure, provided by peripheral cannulation, provided a reliable, less invasive, and safer alternative to femoral central line insertion for determination of the transcaval pressure gradient during the anhepatic phase of liver transplant.

Hemodynamic effects of combined antihypertensive therapy during exercise in men with arterial hypertension and chronic venous diseases

Introduction. Currently, there is insufficient data on the effect of modern antihypertensive therapy (AHT) on venous circulation, especially during physiological stress.Aim of the study – the investigation was to study the hemodynamic effects of a combination of a calcium channel blocker (CCB) and an angiotensin-converting enzyme (ACE) inhibitor during exercise in men with arterial hypertension (AH) and chronic venous diseases (CVD).Material and methods. In 46 men 30–50 years old with AH on the background of AHT, a comparative assessment of the dynamics of SBP, DBP, peripheral venous pressure (PVP), ultrasound parameters of venous blood flow of the left leg in response to physical activity (Ruffier’s test) was performed. The parameters were assessed in 23 patients with hypertension without CVD and 23 patients with hypertension and CVD. We studied the reaction before and after 14 days of combined AHT with the use of CCB (Amlodipine) and an ACE inhibitor (Lisinopril).Results. Before treatment, the response to exercise in patients of both groups was the same and was manifested by a twofold increase in the area of the lumen of the veins and a drop in blood flow velocity. Patients with CVD before treatment with exercise were characterized by an altered systemic hemodynamic response, more frequent cases of venous dilatation and decreased blood flow velocity. After AHT with exercise, both groups showed normalization and identity of SBP. DBP, PVP, a decrease in the severity of venous dilatation and a decrease in blood flow velocity. Patients with CVD after AHT in response to exercise are characterized by more pronounced venous dilatation and higher blood flow velocity.Conclusion. After 14 days of antihypertensive therapy in patients with hypertension without chronic venous disease and in patients with hypertension and chronic venous disease during exercise normalization of systolic blood pressure, diastolic blood pressure, PVP, a decrease in venous dilatation and a decrease in blood flow velocity are noted. Patients with CVD after AHT under load are characterized by varicose veins and accelerated venous blood flow.

Longer sustained Fontan circulation is associated with prolonged hepatic T1 relaxation time on T1 mapping

Abstract Funding Acknowledgements Type of funding sources: None. Background Patients with single ventricle defects may develop Fontan-associated liver disease. T1 mapping has been successfully used for evaluating chronic liver disease in adults. Liver T1 mapping has been also studied in the pediatric patients with single ventricles, and these patients show higher T1 relaxation times compared to the healthy controls. Purpose Our objective was to study the relationship between the cardiac MRI (CMR) T1 mapping relaxation time of the liver and 1) CMR derived hemodynamic parameters, 2) peripheral venous pressure (PVP) measured from a cubital cannula 3) systemic ventricle morphology [LV vs. RV], 4) the age of patient, and 5) alanine transaminase (P-ALAT) levels. Methods This retrospective study included 46 patients with functional single ventricle, which underwent routine CMR at our hospital. Table 1 shows demographic and clinical data of the study population. Statistical analysis were performed with IBM SPSS Statistics v.25 software using independent samples t test, Mann-Whitney U-test or Pearson correlation as appropriate. A p-value less than 0.05 was considered significant. Results The average T1 relaxation time of the liver was longer in patients with RV morphology (p = 0.004). There was a significant moderate positive correlation between the age of the patients and hepatic T1 relaxation time (r = 0.45, p = 0.002), and between hepatic T1 relaxation time and P-ALAT levels (r = 0.5, p = 0.016) (Fig.1). No significant correlations were detected between the T1 times of the liver and hemodynamic parameters of the heart (all tested parameters are listed in the Table1). Ejection fraction and PVP showed a non-significant weak correlation with a hepatic T1 relaxation times (r=-0.3, p = 0,056 and r = 0.3, p = 0,070, respectively). Conclusions T1 mapping times of the liver may reflect Fontan-associated liver disease. We observed connections between the hepatic T1 relaxation times and 1) patients age, 2) systemic ventricle morphology and 3) P-ALAT levels.

Peripheral venous pressure changes during exercise are associated with adverse Fontan outcomes

ObjectiveElevated central venous pressure (CVP) plays an important role in the development of adverse Fontan outcomes. Peripheral venous pressure (PVP) has been validated as a surrogate for CVP in Fontan...

Dimensional disparity between duplex and intravascular ultrasound in the assessment of iliac vein stenosis.

Minimum iliac vein caliber necessary to maintain normal peripheral venous pressure can be derived by the Poiseuille equation. Duplex was compared to intravascular ultrasound (IVUS) in the assessment of iliac vein stenosis in this single center retrospective study. Parallel IVUS and duplex caliber data for common iliac vein (CIV) and external iliac vein (EIV) in 382 limbs were separately compared. One or both segments were stenotic by IVUS criteria in 213 limbs. Neither segment was stenotic by IVUS in 22 limbs. Bland-Altman analyses and Passing-Bablok linear regressions were used. Duplex calibers were dimensionally smaller than corresponding IVUS images of CIV and EIV segments in Bland-Altman comparison by a mean of 54 mm2 and 34 mm2, respectively. Passing-Bablok regression suggested the difference was due to a systematic bias and not proportional. Duplex yields a smaller cross-sectional image of CIV and EIV compared to IVUS. Duplex is not a reliable diagnostic test for iliac vein stenosis.

Anesthetics affect peripheral venous pressure waveforms and the cross-talk with arterial pressure

Analysis of peripheral venous pressure (PVP) waveforms is a novel method of monitoring intravascular volume. Two pediatric cohorts were studied to test the effect of anesthetic agents on the PVP waveform and cross-talk between peripheral veins and arteries: (1) dehydration setting in a pyloromyotomy using the infused anesthetic propofol and (2) hemorrhage setting during elective surgery for craniosynostosis with the inhaled anesthetic isoflurane. PVP waveforms were collected from 39 patients that received propofol and 9 that received isoflurane. A multiple analysis of variance test determined if anesthetics influence the PVP waveform. A prediction system was built using k-nearest neighbor (k-NN) to distinguish between: (1) PVP waveforms with and without propofol and (2) different minimum alveolar concentration (MAC) groups of isoflurane. 52 porcine, 5 propofol, and 7 isoflurane subjects were used to determine the cross-talk between veins and arteries at the heart and respiratory rate frequency during: (a) during and after bleeding with constant anesthesia, (b) before and after propofol, and (c) at each MAC value. PVP waveforms are influenced by anesthetics, determined by MANOVA: p value < 0.01, η2 = 0.478 for hypovolemic, and η2 = 0.388 for euvolemic conditions. The k-NN prediction models had 82% and 77% accuracy for detecting propofol and MAC, respectively. The cross-talk relationship at each stage was: (a) ρ = 0.95, (b) ρ = 0.96, and (c) could not be evaluated using this cohort. Future research should consider anesthetic agents when analyzing PVP waveforms developing future clinical monitoring technology that uses PVP.

Dynamic exercise changes in venous pressure and liver stiffness in Fontan patients: effects of Treprostinil.

Systemic venous hypertension and low cardiac output are believed to be important mediators of liver injury after the Fontan procedure. Pulmonary vasodilators have the potential to improve such haemodynamics. The aim of this study was to assess the acute effects of exercise on liver stiffness and venous pressures and to assess the impact of inhaled Treprostinil on this response. In this prospective, double-blind, placebo-controlled, crossover trial, 14 patients with a Fontan circulation were randomised to inhalation of placebo and Treprostinil. Incremental and constant work rate exercise tests were performed to assess the effect of Treprostinil on exercise tolerance. Venous pressures were measured throughout and liver stiffness at rest and immediately after peak exercise. Mean age was 27.8 ± 7.9 years and 66% were females. Exercise acutely increased liver stiffness by 30% (mean shear wave speed: 2.38 ± 0.71 versus 2.89 ± 0.51 ms, p = 0.02). Peripheral venous pressures increased acutely during both incremental (12.1 ± 2.4 versus 22.6 ± 8.0 mmHg, p < 0.001) and constant work rate exercise (12.5 ± 2.5 versus 23.4 ± 5.2 mmHg, p < 0.001). Overall, Treprostinil failed to attenuate exercise-induced increases in liver stiffness. Compared with placebo, Treprostinil did not significantly impact venous pressure responses, VO2peak, nor exercise endurance times. Peripheral venous pressure increased acutely during exercise by an average of 88% above baseline and was not altered by administration of inhaled Treprostinil. Liver stiffness measured immediately post-exercise increased acutely by an average of 30%, with no attenuation following Treprostinil inhalation.

Hemodynamic reaction to orthostasis in hypertensive men with chronic venous diseases taking a combination of an angiotensin-converting enzyme inhibitor and diuretic

Objective. To assess the hemodynamic reaction to orthostasis in hypertensive men with chronic venous diseases (CVenD) taking a combination of an angiotensin-converting enzyme inhibitor (ACE inhibitor) and a diuretic. Design and methods. We enrolled 44 men aged 30–50 years old with uncontrolled hypertension (HTN) who were taking antihypertensive therapy (AHT). We performed a comparative assessment of the changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, femoral peripheral venous pressure (PVP), diameter and area of the lumen, blood flow velocity in the superficial and deep veins of the left lower limb in response to orthostasis. The patients were divided into two groups: 22 patients with HTN without chronic venous insufficiency, 22 patients with HTN and chronic venous disease. We studied the reaction at 3 minutes of orthostasis before and after 14 days of AHT in a hospital using ACE inhibitors (Perindopril) and a diuretic (Indapamide). Results. Before treatment, the reaction to orthostasis was similar in both groups, we registered a decrease in SBP, PVP, blood flow velocity and an increase in diameter, lumen area of all veins. As a result of treatment, 40 patients reached a level of SBP &lt; 140 mm Hg. Of these, there were 19 patients without CVenD, and 21 patients with CVenD. After treatment, the reaction to orthostasis was similar for the most of the studied parameters. However, there were some differences between the groups. After treatment, patients with HTN and CVenD demonstrated a decrease in SBP, the absence in DBP change, a 4-fold drop in PVP, and orthostatic hypotension was registered in 3 cases. After treatment, in patients with CVenD with orthostasis, SBP and DBP were significantly lower than in patients without CVenD (p = 0,0014 and p = 0,0028, respectively). The difference in SBP between groups after treatment was 12 mm Hg (9%), according to DBP — 6 mm Hg (7%). Conclusions. At baseline and after a 14–15-day use of the combination of ACE inhibitors and a diuretic, the reaction to orthostasis was similar for most of the studied parameters. In patients with HTN and CVenD, the main features of the reaction to orthostasis included a decrease in SBP, the absence of DBP change, a 4-fold drop in PVP, and orthostatic hypotension registered in 3 cases.