Pulse Contour Research Articles

Effect of omega-3 fatty acid ethyl esters on postprandial arterial elasticity in patients with familial hypercholesterolemia

Impaired arterial elasticity reflects increased risk of atherosclerotic cardiovascular disease in patients with familial hypercholesterolemia (FH). Treatment with omega-3 fatty acid ethyl esters (ω-3FAEEs) in FH patients has been shown to improve postprandial triglyceride-rich lipoprotein (TRL) metabolism, including TRL-apolipoprotein(a) [TRL-apo(a)]. Whether ω-3FAEE intervention also improves postprandial arterial elasticity in FH has not been demonstrated. We carried out an 8-week open-label, randomized, crossover trial to test the effect of ω-3FAEEs (4g/day) on postprandial arterial elasticity in 20FH subjects following ingestion of an oral fat load. Fasting and postprandial large (C1) and small (C2) artery elasticity at 4 and 6h were measured by pulse contour analysis of the radial artery. The area under-the-curves (AUCs) (0-6h) for C1, C2, plasma triglycerides and TRL-apo(a) were determined using the trapezium rule. Compared with no treatment, ω-3FAEEs significantly increased fasting (+9%, P<0.05) and postprandial C1 at 4h (+13%, P<0.05) and at 6h (+10%, P<0.05), with improvement in the postprandial C1 AUC (+10%, P<0.01). ω-3FAEEs also decreased postprandial triglyceride and TRL-apo(a) AUCs (-17% and-19%, respectively, P<0.05). ω-3FAEEs had no significant effect on fasting and postprandial C2. The change in C1 AUC was inversely associated with the changes in the AUC of triglycerides (r=-0.609, P<0.01) and TRL-apo(a) (r=-0.490, P<0.05). High-dose ω-3FAEEs improves postprandial large artery elasticity in adults with FH. Reduction in postprandial TRL-apo(a) with ω-3FAEEs may contribute to the improvement in large artery elasticity. However, our findings need to be confirmed in a larger population. https://www. com/NCT01577056.

Treatment of septic shock in two pediatric patients with severe diabetic ketoacidosis using invasive hemodynamic monitoring: a case report

BackgroundDiabetic ketoacidosis (DKA) is a life-threatening complication of diabetes mellitus. DKA associated with shock is a rare condition that occurs due to the fluid deficit or septic shock. It is not easy to differentiate these two conditions by clinical judgment and laboratory findings. Although the fluid therapy is the mainstay in DKA treatment, it looks like a double-edged sword—underhydration may result in organ failure whereas overhydration may lead to pulmonary and cerebral edema (CE).Case presentationHerein, we report on two pediatric patients presenting with DKA and septic shock. The first patient was an 8-year-old boy newly diagnosed with type 1 diabetes mellitus (T1DM) who presented with DKA and septic shock. We used a device for continuous hemodynamic monitoring (proAQT) to estimate his volume status. The patient was extubated 48 hours of hospitalization; the DKA was resolved after 52 hours of admission. He was discharged home in good condition on the 5th day. The second patient was a 13-year-old girl, a known case of T1DM, who presented with mixed DKA- hyperosmolar-hyperglycemic state (HHS) and septic shock. She was intubated and treated according to the data derived from pulse Contour Cardiac Output (PiCCO). After 3 days, she was extubated and transferred to the ward in good condition.ConclusionUsing invasive hemodynamic monitoring in critically ill children with severe DKA and hypotension might guide the physicians for hydration and selecting the most appropriate inotrope.

New Hemodynamic Parameters in Peri-Operative and Critical Care-Challenges in Translation.

Hemodynamic monitoring technologies are evolving continuously-a large number of bedside monitoring options are becoming available in the clinic. Methods such as echocardiography, electrical bioimpedance, and calibrated/uncalibrated analysis of pulse contours are becoming increasingly common. This is leading to a decline in the use of highly invasive monitoring and allowing for safer, more accurate, and continuous measurements. The new devices mainly aim to monitor the well-known hemodynamic variables (e.g., novel pulse contour, bioreactance methods are aimed at measuring widely-used variables such as blood pressure, cardiac output). Even though hemodynamic monitoring is now safer and more accurate, a number of issues remain due to the limited amount of information available for diagnosis and treatment. Extensive work is being carried out in order to allow for more hemodynamic parameters to be measured in the clinic. In this review, we identify and discuss the main sensing strategies aimed at obtaining a more complete picture of the hemodynamic status of a patient, namely: (i) measurement of the circulatory system response to a defined stimulus; (ii) measurement of the microcirculation; (iii) technologies for assessing dynamic vascular mechanisms; and (iv) machine learning methods. By analyzing these four main research strategies, we aim to convey the key aspects, challenges, and clinical value of measuring novel hemodynamic parameters in critical care.

Serum pro-B-type natriuretic peptide levels and cardiac index as adjunctive tools of blunt cardiac injury

BackgroundBlunt cardiac injury (BCI) has a variety of symptoms that may be a potentially life-threatening injury that can lead to death. Depending on the diagnosis of BCI, treatment direction and length of stay may vary. In addition, the utility of other diagnostic tests for cardiac disease as diagnostic tools for BCI remain unclear. The purpose of this study was to investigate the competence of N-terminal pro-B-type natriuretic peptide (NT pro-BNP) and cardiac index (C.I) as adjunctive diagnostic tools for BCI.MethodsFrom January 2018 to March 2020, severe trauma patients with sternum fracture who were admitted to the traumatic intensive care unit (TICU) were included this study. Patients with sternum fracture, 18 years of age or older, and with an injury severity score > 16 who required intensive care were included. Invasive measurement for the analysis of the pulse contour for C.I monitoring and intravenous blood sampling for NT pro-BNP measurement were performed. Sampling and 12-lead electrocardiogram were performed at different time points as follows: immediately after TICU admission and at 24 h and 48 h after trauma.ResultsAmong 103; 33 patients with factors that could affect NT pro-BNP were excluded; therefore, 63 patients were included in this study. According to the American Association for the Surgery of Trauma Cardiac Injury Scale, 33 patients were diagnosed with non-BCI, and 30 patients constituted with BCI. The median ages of the patients were 58 (52–69), and 60 (45–69) years in the non-BCI and BCI groups, respectively (p = 0.77). The median NT pro-BNP values were higher in the BCI group on admission, hospital day (HD) 2, and HD 3, however, no statistical difference was observed (125 (49–245) vs. 130 (47–428) pg/mL, p = 0.08, 124 (68–224) vs. 187 (55–519) pg/mL, p = 0.09, and 121(59–225) vs. 133 (56–600) pg/mL, p = 0.17, respectively). On the contrary, significantly lower values were observed in the median C.I measurement on admission and HD 3 in the BCI group (3.2 (2.8–3.5) vs. 2.6 (2.3–3.5) L/min/m2, p < 0.01 and 3.2 (3.1–3.9) vs. 2.9 (2.4–3.2) L/min/m2, p < 0.01, respectively); however, no significant difference was observed on HD 2 (3.4 (3.0–3.7) vs. 2.6 (2.4–3.4) L/min/m2, p = 0.17), Furthermore, The median lactate levels in the BCI group upon admission, HD 2, and HD 3 were significantly higher than those in the non-BCI group (1.8 (1.1–2.6) vs. 3.1 (2.1–4.4) mmol/L, p < 0.01; 1.3 (0.8–2.3) vs. 3.0 (2.2–4.7) mmol/L, p < 0.01; and 1.5 (0.9–1.5) vs. 2.2 (1.3–3.7) mmol/L, p < 0.01, respectively).ConclusionConsecutive values of NT pro-BNP and C.I show no correlation with ECG-based BCI diagnosis. However, lactate level measurement may help in the early recognition of BCI as an adjunctive tool. It should be noted that this is a hypothesis-generating study for BCI diagnosis. Further studies should be conducted in larger populations with a prospective approach.

Study of the accuracy of a radial arterial pressure waveform cardiac output measurement device after cardiac surgery

BackgroundLess invasive monitoring, such as radial arterial pulse contour analysis (ProAQT® sensor), represents an alternative when hemodynamic monitoring is necessary to guide postoperative management and invasive monitoring is not technically feasible. The aim of the study is to evaluate the accuracy of the ProAQT® sensor cardiac output measurements in comparison with Pulmonary Artery Catheter (PAC) during the postoperative course of patients who underwent cardiac surgery with cardiopulmonary bypass.Case presentationProspective observational study in a Surgical Intensive Care Unit of a tertiary university hospital. Ten patients with a mean age of 73.5 years were included. The main comorbidities were hypertension, diabetes, dyslipidemia and the preoperative left ejection fraction was 43.8 ± 14.5%. Regarding the type of surgery, six patients underwent valve surgery, two underwent coronary artery bypass grafting and two underwent aortic surgery. The cardiac index measured simultaneously by the ProAQT® sensor was compared with the PAC. The parameters were evaluated at predefined time points during the early postoperative courses (6 h, 12 h, 24 h, 48 h and 72 h). The degree of agreement with the cardiac index between the PAC and the ProAQT® sensor along the time points was measured using the concordance correlation coefficient, Bland–Altman analysis, and four-quadrant plot. Sixty-three pairs of measurements were analyzed. We showed that measurements of cardiac index were slightly higher with PAC (β ̂ = − 0.146, p-value = 0.094). The concordance correlation coefficient for the additive model of cardiac index was 0.64 (95% Confidence Interval: 0.36, 0.82), indicating a high concordance between both sensors. Bland-Altmann analysis showed a mean bias of 0.45 L·min−1·m−2, limits of agreement from − 1.65 to 2.3 L·min−1·m−2, and percentage of error was 82.5%. Four-quadrant plot of changes in cardiac index showed a good concordance rate (75%), which increases after applying the exclusion zone (87%).ConclusionsIn patients undergoing cardiac surgery, the ProAQT® sensor may be useful to monitor cardiac index during the postoperative period, especially when more invasive monitoring is not possible.

Changes of cardiac output and velocity time integral in blood return at the end of renal replacement therapy predict fluid responsiveness in critically Ill patients with acute circulatory failure

ObjectivesTo observe if blood return, also defined as the blood infusion test (BIT) could predict fluid responsiveness in critically ill patients with acute circulatory failure and renal replacement therapy (RRT).MethodsThis was a single-center, prospective, diagnostic accuracy study. Before BIT, the passive leg raise test (PLRT) was performed to record the change of cardiac output (ΔCO) by pulse contour analysis, and ΔCO > = 10% was defined as the fluid responder. Meanwhile, the change in velocity time integral (ΔVTI) was recorded by ultrasound. Later, the ΔCO and ΔVTI during BIT were recorded 5–10 min after PLRT. The receiver-operating characteristic curves of ΔCO and ΔVTI of BIT were performed in predicting the fluid responder defined by PLRT.ResultsA total of 43 patients with acute circulatory failure undergoing RRT were enrolled in the present study, and 25 patients (58.1%) were recognized as responders during PLRT. According to the receiver-operating characteristic curves, the cutoff value of ΔCO was 10% and ΔVTI was 9% during BIT with the area under curve of 0.96 and 0.94, respectively.ConclusionsBIT in RRT could identify fluid responsiveness in critically ill patients with shock.Trial registrationChiCTR-DDD-17010534. Registered on 30/01/2017 (retrospective registration).

The Impact of Recirculation on Extracorporeal Gas Exchange and Patient Oxygenation during Veno-Venous Extracorporeal Membrane Oxygenation-Results of an Observational Clinical Trial.

Recirculation during veno-venous extracorporeal membrane oxygenation reduces extracorporeal oxygen exchange and patient oxygenation. To minimize recirculation and maximize oxygen delivery (DO2) the interaction of cannulation, ECMO flow and cardiac output requires careful consideration. We investigated this interaction in an observational trial. In 19 patients with acute respiratory distress syndrome and ECMO, we measured recirculation with the ultrasound dilution technique and calculated extracorporeal oxygen transfer (VO2), extracorporeal oxygen delivery (DO2) and patient oxygenation. To assess the impact of cardiac output (CO), we included CO measurement through pulse contour analysis. In all patients, there was a median recirculation rate of approximately 14-16%, with a maximum rate of 58%. Recirculation rates &gt;35% occurred in 13-14% of all cases. In contrast to decreasing extracorporeal gas exchange with increasing ECMO flow and recirculation, patient oxygenation increased with greater ECMO flows. High CO diminished recirculation by between 5-20%. Extracorporeal gas exchange masks the importance of DO2 and its effects on patients. We assume that increasing DO2 is more important than reduced VO2. A negative correlation of recirculation to CO adds to the complexity of this phenomenon. Patient oxygenation may be optimized with the direct measurement of recirculation.

Experimental evaluation of a pressure recording analytical method (PRAM), a pulse contour analysis method, for monitoring cardiac output in dogs

Introduction: The PRAM has been evaluated in dogs under steady-state hemodynamic conditions, and this study evaluated PRAM under dynamic circulatory conditions, created by infusion of sympathomimetic drugs.

Current status and training needs of trainee anesthesiologists in lung transplantation anesthesia in China: A single-center survey

BackgroundPerioperative management involving anesthesiologists plays an important role in prognosis of recipients after lung transplantation. Since the development of lung transplantation, the demand for specialized anesthesiologists continues to increase. As the largest lung transplant center in China, the Wuxi People's Hospital was tasked with trainee anesthesiologists throughout the country in lung transplantation anesthesia. This study aimed to evaluate the current status and training needs of anesthesiologists for the anesthetic management of lung transplantation in Wuxi People's Hospital between 2015 to 2020. MethodsOverall, 53 trainee anesthesiologists for lung transplantation from 35 hospitals were investigated anonymously in our survey. The questionnaire included the anesthesiologists' demographic information, level of satisfaction, training needs and current status in their hospitals. We divided the doctors into two groups depending on the trainee anesthesiologists’ seniority and professional title: intermediate and senior. Survey data were compared between the groups. ResultsSignificantly more doctors in senior-level positions had clinical research experience than did doctors in intermediate-level positions (P = 0.041). All doctors were highly or very highly satisfied with the training received. Doctors in intermediate-level positions preferred training periods of 4–6 months, while those in senior-level positions preferred 1–3 months of training (P = 0.044). Most doctors considered theoretical courses to be lacking (69.0%), followed by a lack of scenario simulation teaching (54.8%). The most desirable programs were transesophageal echocardiography (TEE, 71.4%) and extracorporeal membrane oxygenation (ECMO, 64.3%). ECMO technology was available in the hospitals of 95.2% of respondents; however, only 2.4% of doctors said the anesthesiology department took charge of perioperative ECMO. Significantly more senior-level doctors chose calibrated pulse contour analysis (P = 0.018) and significantly more intermediate-level ones chose TEE (P = 0.049). Disappointingly, 21.4% doctors reported a lack of certification evaluation for trainee anesthesiologists at their hospitals. ConclusionsDifferent training programs should be set up according to the trainee anesthesiologists’ level of seniority and training needs. Theoretical courses and scenario simulation training must be added to improve the training program. Moreover, the training of TEE and ECMO requires greater attention. Finally, a standardized completion assessment is required for trainee anesthesiologists.

Blood pressure estimation by spatial pulse-wave dynamics in a facial video.

We propose a remote method to estimate continuous blood pressure (BP) based on spatial information of a pulse-wave as a function of time. By setting regions of interest to cover a face in a mutually exclusive and collectively exhaustive manner, RGB facial video is converted into a spatial pulse-wave signal. The spatial pulse-wave signal is converted into spatial signals of contours of each segmented pulse beat and relationships of each segmented pulse beat. The spatial signal is represented as a time-continuous value based on a representation of a pulse contour in a time axis and a phase axis and an interpolation along with the time axis. A relationship between the spatial signals and BP is modeled by a convolutional neural network. A dataset was built to demonstrate the effectiveness of the proposed method. The dataset consists of continuous BP and facial RGB videos of ten healthy volunteers. The results show an adequate estimation of the performance of the proposed method when compared to the ground truth in mean BP, in both the correlation coefficient (0.85) and mean absolute error (5.4 mmHg). For comparison, the dataset was processed using conventional pulse features, and the estimation error produced by our method was significantly lower. To visualize the root source of the BP signals used by our method, we have visualized spatial-wise and channel-wise contributions to the estimation by the deep learning model. The result suggests the spatial-wise contribution pattern depends on the blood pressure, while the pattern of pulse contour-wise contribution pattern reflects the relationship between percussion wave and dicrotic wave.

Noninvasive evaluation of the hemodynamic status in patients after heart transplantation or left ventricular assist device implantation.

IntroductionHemodynamic assessment is crucial after heart transplantation (HTX) or left ventricular assist device (LVAD) implantation. Gold-standard is invasive assessment via thermodilution (TD). Noninvasive pulse contour analysis (NPCA) is a new technology that is supposed to determine hemodynamics completely noninvasive. We aimed to validate this technology in HTX and LVAD patients and conducted a prospective single-center cohort study.MethodsPatients after HTX or LVAD implantation underwent right heart catheterization including TD. NPCA using the CNAP Monitor (V.5.2.14; CNSystems Medizintechnik AG, Graz, Austria) was performed simultaneously. Three TD measurements were compared with simultaneous NPCA measurements for hemodynamic assessment. To describe the agreement between TD and NPCA, Bland–Altman analysis was done.ResultsIn total, 28 patients were prospectively enrolled (HTX: n = 10, LVAD: n = 18). Bland-Altman analysis revealed a mean bias of +1.05 l/min (limits of agreement ± 4.09 l/min, percentage error 62.1%) for cardiac output (CO). In LVAD patients, no adequate NPCA signal could be obtained. In 5 patients (27.8%), any NPCA signal could be detected, but was considered as low signal quality.ConclusionIn conclusion, according to our limited data in a small cohort of HTX and LVAD patients, NPCA using the CNAP Monitor seems not to be suitable for noninvasive evaluation of the hemodynamic status.

Dynamic changes of pulse pressure but not of pulse pressure variation during passive leg raising predict preload responsiveness in critically ill patients with spontaneous breathing activity

PurposeTo evaluate whether the changes in arterial pulse pressure (PP) and/or pulse pressure variation (PPV) during passive leg raising (PLR) can be used to evaluate preload responsiveness in patients with spontaneous breathing activity. Materials and methodsPatients ventilated with pressure support mode or totally spontaneously breathing were prospectively included. The values of PP and PPV were recorded before and at the end of PLR. The changes in cardiac index (CI) or the velocity-time integral (VTI) of the left ventricular outflow tract during PLR were tracked by the pulse contour analysis or transthoracic echocardiography. Patients exhibiting an increase in CI ≥ 10% or VTI ≥ 12% during PLR were defined as preload responders. ResultsAmong 33 patients included, 28 (80%) received norepinephrine and 14 were preload responders. The increase in PP > 2 mmHg in absolute value (4% in percentage) during PLR (PLRPP) predicted preload responsiveness with an area under the receiver operating characteristic (AUROC) of 0.76 ± 0.09 (p = 0.003 vs. AUROC of 0.5). The changes in PPV during PLR, however, failed to predict preload responsiveness (p = 0.82 vs. AUROC of 0.5). ConclusionIn patients with full spontaneous breathing activity, PLR-induced changes in PP had a fair ability to assess preload responsiveness even when norepinephrine was administered.Registration number:ClinicalTrials.gov (NCT04369027).

Evaluation of Pulse Contour Markers using an A-Mode Ultrasound: Association with Carotid Stiffness Markers and Ageing.

Vascular ageing is directly associated with the blood vessel wall structural and functional abnormalities. Pulse morphology carries information on these abnormalities, and pulse contour analysis (PCA) identifies key amplitudes and timing information on the pulse waveforms that has a prognostic value towards cardiovascular risk stratification. PCA markers derived from second derivative waveforms represent the accelerative and decelerative phase of an arterial pulse. In this work, second derivative diameter waveforms of central arteries such as carotid artery are obtained using an A-mode ultrasound device. The derived PCA markers (b/a, c/a, d/a, e/a, (b-c-d-e)/a) from diameter waveform is investigated for its association with central stiffness markers and aging. An observational and cross-sectional study on 106 subjects (51 male/55 females) was conducted for this investigation. The highest correlation (r = 0.5, P < 0.001) was observed between c/a and PWV, and the lowest correlation was between c/a and AC. Group average values of PCA markers for each age decade group were correlated strongly (r > 0.9, p < 0.001) with age. A change > 19% was observed between the group average values of PCA markers of the normotensive and hypertensive population. The applicability of aforesaid PCA markers on central pulse waveforms, measured using a noninvasive device in resource-limited field settings, would accelerate such large scale vascular screening that is essential to understanding the cardiovascular risks at a population level. Clinical Relevance- This study provides an investigation into using second derivative diameter waveforms obtained from the carotid artery to find its associations with arterial stiffness and ageing.

Association of Local Arterial Stiffness and Windkessel Model Parameters with Ageing in Normotensives and Hypertensives.

Computation of arterial stiffness is a well-established, widely accepted method for estimating vascular age. Although carotid-femoral pulse wave velocity is typically used for vascular age assessment, most recent studies have reported the need to consider a combination of local and regional stiffness indices possessing distinct association with the vascular structure and/or function for better prediction of early vascular ageing syndrome. In this work, we investigate the association of clinically validated local stiffness (obtained using biomechanical relations), global stiffness (obtained from 3-element Windkessel modelling), and pulse contour indices from the aorta with ageing and their distribution in normotensives and hypertensives. The analysis was performed on 420 (virtual) subjects (age: 65 ± 11 years) with an equal proportion of hypertensive (age: 65 ± 11 years) and normotensive (age: 65 ± 11 years) subjects. Multivariate linear regression analysis revealed an independent association of each of the indices with age (Adjusted r = 0.75 p < 0.01). Specific stiffness index (r = 0.67, p < 0.001), Augmentation index (r = 0.55, p< 0.001) and total arterial compliance (r = -0.50, p < 0.001) depicted highest correlation with age. There was a significant difference (> 16%, p < 0.001) in mean values of the measured indices between hypertensive and normotensive subjects. The study findings further emphasize the need to combine multiple non-invasive vascular markers to capture the unique aspects of age-induced arterial wall remodelling for reliable monitoring and management of the early vascular ageing syndrome. Clinical Relevance- This study demonstrates an independent and combined predictive role of local/global stiffness and pulse contour indices in ageing.

The Application of PiCCO-guided Fluid Resuscitation in Patients With Traumatic Shock.

The aim of this study was to evaluate the application of pulse contour cardiac output (PiCCO) in patients with traumatic shock. Seventy-eight patients with traumatic shock were included and grouped. The control group (CG, n = 39) underwent fluid resuscitation through transthoracic echocardiography (TTE) monitoring, and the research group (RG, n = 39) received PiCCO-guided fluid resuscitation. The mechanical ventilation time, duration of vasoactive drug use, and duration of stay in the intensive care unit were lower in the RG compared to the CG (P < .05). At 72h after fluid resuscitation, the mean arterial pressure and central venous pressure in the RG were higher than those in the CG (P < .05). The stroke volume variation and distensibility index of the inferior vena cava were lower at 72h after fluid resuscitation, but the levels of extravascular lung water, global end-diastolic volume index, and intrathoracic blood volume index were higher in the RG (P < .05). The levels of endothelial 1, nitrogen monoxide, tumor necrosis factor-α, procalcitonin, C-reactive protein, and partial pressure of carbon dioxide at 72h after fluid resuscitation in the RG were lower than those in the CG (P < .05). PiCCO-guided liquid resuscitation may help to accurately evaluate the volumetric parameters, alleviate symptoms of ischemia and hypoxia, regulate hemodynamics and blood gas analysis, reduce inflammatory reactions, improve endothelial functions, and effectively guide the usage of vascular active drugs.

To identify normovolemia in humans: The stroke volume response to passive leg raising vs. head-down tilt.

Volume responsiveness can be evaluated by tilting maneuvers such as head‐down tilt (HDT) and passive leg raising (PLR), but the two procedures use different references (HDT the supine position; PLR the semi‐recumbent position). We tested whether the two procedures identify “normovolemia” by evaluating the stroke volume (SV) and cardiac output (CO) responses and whether the peripheral perfusion index (PPI) derived from pulse oximetry provides similar information. In randomized order, 10 healthy men were exposed to both HDT and PLR, and evaluations were made also when the subjects fasted. Central cardiovascular variables were derived by pulse contour analysis and changes in central blood volume assessed by thoracic electrical admittance (TEA). During HDT, SV remained stable (fasted 110 ± 16 vs. 109 ± 16 ml; control 113 ± 16 vs. 111 ± 16 ml, p > 0.05) with no change in CO, TEA, PPI, or SV variation (SVV). In contrast during PLR, SV increased (fasted 108 ± 17 vs. 117 ± 17 ml; control 108 ± 18 vs. 117 ± 18 ml, p < 0.05) followed by an increase in TEA (p < 0.05) and CO increased when subjects fasted (6.7 ± 1.5 vs. 7.1 ± 1.5, p = 0.007) with no change in PPI or SVV. In conclusion, SV has a maximal value for rest in supine men, while PLR restores SV as CBV is reduced in a semi‐recumbent position and the procedure thereby makes healthy volunteers seem fluid responsive.

Associations of plasma omega-3 and omega-6 pufa levels with arterial elasticity: the multi-ethnic study of atherosclerosis.

Literature examining the relationship of circulating omega-3 and omega-6 polyunsaturated fatty acids [n-3(ω-3) and n-6 (ω-6) PUFAs] and arterial elasticity in large cohort-based populations are lacking. We investigated the association of circulating ω-3and ω-6 PUFAs with large artery elasticity (LAE) and small artery elasticity (SAE) in participants from the Multi-Ethnic Study of Atherosclerosis (MESA). A total of 6124 participants (mean age 61.9; 52% female; 38% White, 27% Black, 22% Hispanic, and 13% Chinese-American) with plasma phospholipid PUFAs and arterial elasticity measured at baseline were included. LAE and SAE were derived from pulse contour analysis of the radial artery in all subjects in a supine position using tonometry. Linear regression models were used to determine associations for levels of (1) each circulating fatty acid, (2) total ω-3PUFAs, and (3) total ω-6 PUFAs with log-transformed LAE and SAE. Each standard deviation (SD) increment in circulating levels of total ω-3 PUFAs, eicosapentaenoic acid, and docosahexaenoic acid were associated with a 0.017 ml/mmHg, 0.017 ml/mmHg, and 0.015 ml/mmHg higher LAE respectively (p values all <0.01). No significant trends were observed for ω-3 PUFAs levels with SAE.22 Similarly, no significant trends were observed for ω-6 PUFA levels with either LAE or SAE. In a multi-ethnic cohort of individuals free of baseline cardiovascular disease, higher plasma levels of total and individual ω-3 PUFAs were associated with an increased LAE. Further understanding into differential associations of ω-6 PUFAs with LAE and SAE is needed.

P76: Simulating aortic flow and radial pressure waveforms using a mock circulatory loop for testing pulse contour cardiac output monitoring systems

P76: Simulating aortic flow and radial pressure waveforms using a mock circulatory loop for testing pulse contour cardiac output monitoring systems

P232 EXERTIONAL BREATHLESSNESS IN HYPERTROPHIC CARDIOMYOPATHY: OBSTRUCTION–INDEPENDENT SYMPTOMS IN A “PARADOXICAL” RESPONSE TO EXERCISE

Abstract A 66–y.o. man with hypertrophic cardiomyopathy presented with residual exertional dyspnea NYHA III a few years after surgical myectomy, mitral valve repair and ICD implantation. Echocardiography showed residual mild septal hypertrophy and mitral regurgitation (MR), and a variable obstruction of left ventricular outflow tract (LVOT), witnessed by a pressure gradient ranging from 15 to 50–70 mmHg (Figure 1). Exercise echocardiography did not suggest exercise–induced LVOT obstruction (LVOTO) or functional MR. We thus performed a thorough invasive hemodynamic evaluation at rest and during exercise. LVOTO was present at rest, with a maximum pressure gradient of 90–100 mmHg and typical “spike–and–dome” configuration of the aortic pulse contour (Figure 2), with LV end–diastolic pressure (LVEDP) at the upper limit of normal (15 mmHg) and normal pulmonary hemodynamics. During exercise, we observed a paradoxical reduction of the LVOTO (30–40 mmHg at peak, Figure 2). Pulmonary hypertension developed during exercise, due to LV diastolic dysfunction, witnessed by a marked increase in pulmonary artery wedge pressure and LVEDP (up to 25 mmHg and 30 mmHg at peak, respectively). Cardiac output (CO) reserve was at the lower limits of normal, mainly due to chronotropic incompetence, responsible for a mildly reduced exercise capacity (peak oxygen consumption was 20 mL/Kg/min, 75% of predicted). Thus, cardiac catheterization confirmed the presence of a relevant LVOTO at rest, that was not directly related to exertional symptoms. These latter were mainly attributable to LV diastolic dysfunction and reduced CO reserve. These findings helped us driving treatment decision in a tailored way: beta–blockers were not uptitrated, because of their negative inotropic effect, and high–risk septal reduction therapies were excluded, since exertional symptoms were unrelated to LVOTO. However, an attempt to reduce LVOTO was done by DDD sequential pacing through the ICD. Pacing could induce mechanical dyssynchrony and reduce LVOTO by increasing the end–systolic LVOT diameter. The simultaneous echocardiographic monitoring highlighted an acute reduction of LVOT gradient from 50–70 mmHg to 20–30 mmHg (Figure 3). This case suggests that, in well–selected cases, patients’ management based on pathophysiological reasoning may help to define the etiopathogenetic mechanism underlying symptoms, and to drive treatment decision in a patient–centered way.

Haemodynamic changes during radical nephrectomy with inferior vena cava thrombectomy: A pilot study.

Haemodynamic changes during radical nephrectomy with inferior vena cava thrombectomy: A pilot study.