Increase In Stroke Volume Index Research Articles

Predicting fluid responsiveness in spontaneously breathing parturients undergoing caesarean section via carotid artery blood flow and velocity time integral measured by carotid ultrasound: a prospective cohort study

BackgroundPresent evidence suggests that the Doppler ultrasonographic indices, such as carotid artery blood flow (CABF) and velocity time integral (VTI), had the ability to predict fluid responsiveness in non-obstetric patients. The purpose of this study was to assess their capacity to predict fluid responsiveness in spontaneous breathing parturients undergoing caesarean section and to determine the effect of detecting and management of hypovolemia (fluid responsiveness) on the incidence of hypotension after anaesthesia.MethodsA total of 72 full term singleton parturients undergoing elective caesarean section were enrolled in this study. CABF, VTI, and hemodynamic parameters were recorded before and after fluid challenge and assessed by carotid artery ultrasonography. Fluid responsiveness was defined as an increase in stroke volume index (SVI) of 15% or more after the fluid challenge.ResultsThirty-one (43%) patients were fluid responders. The area under the ROC curve to predict fluid responsiveness for CABF and VTI were 0.803 (95% CI, 0.701–0.905) and 0.821 (95% CI, 0.720–0.922). The optimal cut-off values of CABF and VTI for fluid responsiveness was 175.9 ml/min (sensitivity of 74.0%; specificity of 78.0%) and 8.7 cm/s (sensitivity of 67.0%; specificity of 90.0%). The grey zone for CABF and VTI were 114.2-175.9 ml/min and 6.8–8.7 cm/s. The incidence of hypotension after the combined spinal-epidural anaesthesia (CSEA) was significantly higher in the Responders group 25.8% (8/31) than in the Non-Responders group 17.1(7/41) (P < 0.001). The total incidence of hypotension after CSEA of the two groups was 20.8% (15/72).ConclusionsUltrasound evaluation of CABF and VTI seem to be the feasible parameters to predict fluid responsiveness in parturients undergoing elective caesarean section and detecting and management of hypovolemia (fluid responsiveness) could significantly decrease incidence of hypotension after anaesthesia.Trial registrationThe trial was registered at the Chinese Clinical Trial Registry (ChiCTR) (www.chictr.org), registration number was ChiCTR1900022327 (The website link: https://www.chictr.org.cn/showproj.html?proj=37271 ) and the date of trial registration was in April 5, 2019. This study was performed in accordance with the Declaration of Helsinki and approved by the Research Ethics Committee of Women’s Hospital, Zhejiang University School of Medicine (20,180,120).

CAROTID ARTERY ULTRASOUND FOR ASSESSING FLUID RESPONSIVENESS IN PATIENTS UNDERGOING MECHANICAL VENTILATION WITH LOW TIDAL VOLUME AND PRESERVED SPONTANEOUS BREATHING.

Objective : This study aimed to investigate whether changes in carotid artery corrected flow time (ΔFTc bolus ) and carotid artery peak flow velocity respiratory variation (Δ V peak bolus ) induced by the fluid challenge could reliably predict fluid responsiveness in mechanically ventilated patients with a tidal volume < 8 mL/kg Predicted Body Weight while preserving spontaneous breathing. Methods : Carotid artery corrected flow time, Δ V peak, and hemodynamic data were measured before and after administration of 250 mL crystalloids. Fluid responsiveness was defined as a 10% or more increase in stroke volume index as assessed by noninvasive cardiac output monitoring after the fluid challenge. Results : A total of 43 patients with acute circulatory failure were enrolled in this study. Forty-three patients underwent a total of 60 fluid challenges. The ΔFTc bolus and Δ V peak bolus showed a significant difference between the fluid responsiveness positive group (n = 35) and the fluid responsiveness negative group (n = 25). Spearman correlation test showed that ΔFTc bolus and Δ V peak bolus with the relative increase in stroke volume index after fluid expansion ( r = 0.5296, P < 0.0001; r = 0.3175, P = 0.0135). Multiple logistic regression analysis demonstrated that ΔFTc bolus and Δ V peak bolus were significantly correlated with fluid responsiveness in patients with acute circulatory failure. The areas under the receiver operating characteristic curves of ΔFTc bolus and Δ V peak bolus for predicting fluid responsiveness were 0.935 and 0.750, respectively. The optimal cutoff values of ΔFTc bolus and Δ V peak bolus were 0.725 (sensitivity = 97.1%, specificity = 84%) and 4.21% (sensitivity = 65.7%, specificity = 80%), respectively. Conclusion : In mechanically ventilated patients with a tidal volume < 8 mL/kg while preserving spontaneous breathing, ΔFTc bolus and Δ V peak bolus could predict fluid responsiveness. The predictive performance of ΔFTc bolus was superior to Δ V peak bolus .

Effects of canagliflozin on cardiac remodeling and hemodynamic parameters in patients with type 2 diabetes mellitus

Sodium-glucose cotransporter type 2 (SGLT2) inhibitors have demonstrated to reduce cardiovascular risk in patients with type 2 diabetes mellitus (T2DM) in large trials independent of glycemic control. The mechanisms of this cardioprotective property remain uncertain. Evidence suggests positive hemodynamic changes and favorable cardiac remodeling contributing to the clinical outcomes but results were conflicting. We aim to investigate the potential impact on hemodynamic parameters, cardiac structure and functions. This prospective observational study included T2DM patients receiving canagliflozin 100 mg per day in addition to their antidiabetic treatment. We analyzed hemodynamic parameters assessed by echocardiographic measurements and impedance cardiography (ICG) to evaluate systolic and diastolic functions from baseline to 24 weeks after treatment. A total of 47 patients (25 males and 22 females) averaging 64.6 ± 10.9 years had a significant reduction in HbA1c, body weight, and systolic blood pressure. Hematocrit increased significantly, while NT-proBNP remained unchanged. E/e′, left atrium (LA) volume, and LA stiffness were reduced, while left ventricle (LV) global longitudinal strain (GLS) and LA strain rates increased at 24 weeks by conventional and speckle tracking echocardiography. LV mass and ejection fraction showed no differences. ICG suggested significant improvement in hemodynamic parameters with increased stroke volume index and cardiac output index and decreased systemic vascular resistance index at 12 and 24 weeks. Canagliflozin improved hemodynamic parameters and had a favorable impact on LA and LV reverse remodeling. These changes may explain the beneficial effect on cardiovascular outcomes in large clinical trials.

Canagliflozin improves hemodynamic parameters by impedance cardiography and left ventricular diastolic function in patients with type 2 diabetes mellitus

Abstract Background Sodium-glucose cotransporter type 2 (SGLT2) inhibitors have been shown to reduce cardiovascular risk in patients with type 2 diabetes mellitus (T2DM) in large trials, independent of glycemic control. The mechanisms behind this cardioprotective effect remain uncertain, although evidence suggests that positive hemodynamic changes and favorable cardiac remodeling may contribute to the clinical outcomes. However, results have been conflicting. The aim of this study was to investigate the potential impact of canagliflozin on hemodynamic parameters, cardiac structure, and function. Methods This prospective observational study included T2DM patients receiving canagliflozin 100mg per day in addition to their antidiabetic treatment. We analyzed hemodynamic parameters assessed by impedance cardiography (ICG) and echocardiographic measurements to evaluate systolic and diastolic functions from baseline to 24 weeks after treatment. Results A total of 47 patients (25 males and 22 females) with an average age of 64.4±10.8 years experienced a significant reduction in HbA1c, hematocrit, body weight, and systolic blood pressure. NT-proBNP levels remained the same. ICG suggested significant improvement in hemodynamic parameters, with increased stroke volume index and cardiac output index and decreased systemic vascular resistance index at 12 and 24 weeks. E/e’, left atrial (LA) volume, and LA stiffness were reduced, while left ventricular (LV) global longitudinal strain (GLS) and LA strain rates increased at 24 weeks, as measured by conventional and speckle tracking echocardiography. LV mass and ejection fraction showed no differences. Conclusions Canagliflozin improved hemodynamic parameters and had a favorable impact on LA and LV reverse remodeling. These changes may explain the beneficial effect on cardiovascular outcomes seen in large clinical trials.

Abstract 14195: Right Ventricular Outflow Tract Diameter Increase With the Low-Moderate Workload: A Prospective Simultaneous Exercise Echocardiography and Invasive Cardiopulmonary Exercise Testing Study

Background: While cardiac output at rest can be estimated non-invasively with echocardiogram, change in left ventricular or right ventricular outflow tract diameter (RVOTd) with exercise makes the cardiac output estimation inaccurate. Hypothesis: RVOTd increases with exercise proportionally with an incremental workload and is determined by stroke volume augmentation. Aims: 1. Define a workload-based change in RVOTd in subjects undergoing invasive cardiopulmonary exercise test (iCPET). 2. Correlate RVOTd at exercise stages with iCPET metrics. Methods: 20 subjects undergoing simultaneous echocardiogram and iCPET were enrolled in a prospective study. Exercise datapoints were acquired at 25 W (n=20), 50W (n=16), 75W (n=14), 100W (n=6). Three hemodynamic groups included: HFpEF (n=12), PAH (n=5), controls (n=3). Utilizing iCPET-based direct Fick cardiac output and stroke volume, RVOTd was reverse engineered with RVOT velocity time integral, per ASE guidelines. Pearson correlation was used to assess correlation of RVOTd with hemodynamic metrics. p&lt;0.05* Results: In overall cohort, age was 64±12 years, BMI 31.2±4.9 Kg/m 2 , female 60%, peak VO 2 13.7±5.7 mL/Kg.min -1 and V E /VCO 2 37±8. Increase in RVOTd with exercise is represented in the Figure. In comparison to rest, RVOTd increased significantly even at low-25W (+4.1±13.6%*) and moderate-50W (+7.6±17.2%*) workloads. Overall, RVOTd increased by 4-5% every 25W. At high workload (100W), the diameter increased by 24% (n=6). There were no differences in RVOT diameter between subgroups. RVOTd at four exercise stages (25W, 50W, 75W, 100W) correlated significantly with stroke volume index (r=0.68*, 0.80*, 0.23, 0.64) and cardiac output (r=0.50*, 0.80*, 0.08, 0.68), but non-significantly with heart rate (r=-0.15, 0.19, -0.10, 0.68). Conclusion: RVOTd increases by 4-5% every 25W on an incremental workload protocol. This behavior is predominantly associated with an increase in stroke volume index with exercise.

Respiratory variation in the internal jugular vein does not predict fluid responsiveness in the prone position during adolescent idiopathic scoliosis surgery: a prospective cohort study

BackgroundRespiratory variation in the internal jugular vein (IJVV) has not shown promising results in predicting volume responsiveness in ventilated patients with low tidal volume (Vt) in prone position. We aimed to determine whether the baseline respiratory variation in the IJVV value measured by ultrasound might predict fluid responsiveness in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF) with low Vt.MethodsAccording to the fluid responsiveness results, the included patients were divided into two groups: those who responded to volume expansion, denoted the responder group, and those who did not respond, denoted the non-responder group. The primary outcome was determination of the value of baseline IJVV in predicting fluid responsiveness (≥15% increases in stroke volume index (SVI) after 7 ml·kg-1 colloid administration) in patients with AIS undergoing PSF during low Vt ventilation. Secondary outcomes were estimation of the diagnostic performance of pulse pressure variation (PPV), stroke volume variation (SVV), and the combination of IJVV and PPV in predicting fluid responsiveness in this surgical setting. The ability of each parameter to predict fluid responsiveness was assessed using a receiver operating characteristic curve.ResultsFifty-six patients were included, 36 (64.29%) of whom were deemed fluid responsive. No significant difference in baseline IJVV was found between responders and non-responders (25.89% vs. 23.66%, p = 0.73), and no correlation was detected between baseline IJVV and the increase in SVI after volume expansion (r = 0.14, p = 0.40). A baseline IJVV greater than 32.00%, SVV greater than 14.30%, PPV greater than 11.00%, and a combination of IJVV and PPV greater than 64.00% had utility in identifying fluid responsiveness, with a sensitivity of 33.33%, 77.78%, 55.56%, and 55.56%, respectively, and a specificity of 80.00%, 50.00%, 65.00%, and 65.00%, respectively. The area under the receiver operating characteristic curve for the baseline values of IJVV, SVV, PPV, and the combination of IJVV and PPV was 0.52 (95% CI, 0.38–0.65, p=0.83), 0.54 (95% CI, 0.40–0.67, p=0.67), 0.58 (95% CI, 0.45–0.71, p=0.31), and 0.57 (95% CI, 0.43–0.71, p=0.37), respectively.ConclusionsUltrasonic-derived IJVV lacked accuracy in predicting fluid responsiveness in patients with AIS undergoing PSF during low Vt ventilation. In addition, the baseline values of PPV, SVV, and the combination of IJVV and PPV did not predict fluid responsiveness in this surgical setting.Trail registrationThis trial was registered at www.chictr.org (ChiCTR2200064947) on 24/10/2022. All data were collected through chart review.

Ambulatory Monitoring of Cerebrovascular Responses to Upright Posture and Walking in Older Adults With Heart Failure

BackgroundInsufficient cardiac output in individuals with heart failure (HF) limits daily functioning and reduces quality of life. Although lower cerebral perfusion, secondary to limitations in cardiac output, has been observed during moderate-intensity efforts, individuals with HF also may be at risk for lower perfusion during even low-intensity ambulatory activities. MethodsWe determined whether HF is associated with an altered cerebrovascular response to low-intensity activities representative of typical challenges of daily living. In this study, we monitored central hemodynamics and middle cerebral artery blood velocity (MCAv) and cerebral tissue oxygenation (near-infrared spectroscopy) in 10 individuals with HF (aged 78 ± 4 years; left ventricular ejection fraction 20%-61%) and 13 similar-aged controls (79 ± 8 years; 52%–73%) during 3 randomized transitions, as follows: (i) supine-to-standing; (ii) sitting-to-slow-paced over-ground walking; and (iii) sitting-to-normal-paced over-ground walking. ResultsThroughout supine, sitting, standing, and both walking conditions, individuals with HF had lower cardiac index and cerebral tissue oxygenation than controls (P < 0.05), and MCAv was lower across the range of blood pressure in HF patients (P = 0.051) and during walking only (P = 0.011). Individuals with HF had an attenuated increase in stroke volume index and cardiac index during normal-paced walking, compared to controls (P < 0.01). ConclusionsThe indices of cerebral perfusion from MCAv and cerebral oxygenation were lower during ambulatory activities in individuals with HF; however, relationships between MCAv and blood pressure were not different between those with HF and controls, indicating no difference in static cerebral autoregulation.

AATS 2023: Left ventricular restoration with scar exclusion in the surgical treatment for ischemic heart failure

ObjectivePost-infarction myocardial scar as detected by cardiac magnetic resonance (CMR) is associated with adverse left ventricular (LV) remodeling and negatively affects the prognosis. We sought to analyze the impact of left ventricular restoration (LVR) with asynergic scar exclusion on long-term outcomes for patients with ischemic heart failure (IHF). MethodsFrom January 2005, 134 consecutive patients with IHF underwent scar-exclusive LVR. Among the 131 survivors, 108 patients had paired late gadolinium enhancement (LGE)-CMR preoperatively and one year after, and represent the study population. Patients were divided into two groups according to whether their post-LVR residual percentage of scarred LV perimeter was <35% (%Scar <35; n = 55) or more (%Scar ≥35; n = 53). We compared the two groups, by looking at LGE-CMR outcomes, and at long-term survival and cardiac event (hospitalization for cardiac causes)-free survival. ResultsPostoperative LV end-systolic volume index decreased significantly and ejection fraction increased with significant increase in stroke volume index (P < 0.05 for both). LV diastolic function of the left atrial volume index was significantly improved in patients with residual %Scar <35 than in those with %Scar ≥35 (P interaction = 0.005). Median survival in patients with residual %Scar <35 and ≥ 35 were 8.3 (4.5–12.2) years and 6.8 (1.8–11.8) years respectively (P = 0.106). Median cardiac event-free survival in patients with %Scar <35 and ≥ 35 were 8.0 (3.9–12.1) years and 4.8 (0.8–8.8) years respectively (P < 0.001). ConclusionsScar-exclusive LVR yielded sustainable improvement in LV function and favorable long-term survival regardless of the extent of residual scar. The LVR should be performed to attain scar exclusion in the surgical treatment for IHF, which in turn might protectively affect LV diastolic function and cardiac event-free survival.

Diagnostic accuracy of the peripheral venous pressure variation induced by an alveolar recruitment maneuver to predict fluid responsiveness during high-risk abdominal surgery

BackgroundIn patients undergoing high-risk surgery, it is recommended to titrate fluid administration using stroke volume or a dynamic variable of fluid responsiveness (FR). However, this strategy usually requires the use of a hemodynamic monitor and/or an arterial catheter. Recently, it has been shown that variations of central venous pressure (ΔCVP) during an alveolar recruitment maneuver (ARM) can predict FR and that there is a correlation between CVP and peripheral venous pressure (PVP). This prospective study tested the hypothesis that variations of PVP (ΔPVP) induced by an ARM could predict FR.MethodsWe studied 60 consecutive patients scheduled for high-risk abdominal surgery, excluding those with preoperative cardiac arrhythmias or right ventricular dysfunction. All patients had a peripheral venous catheter, a central venous catheter and a radial arterial catheter linked to a pulse contour monitoring device. PVP was always measured via an 18-gauge catheter inserted at the antecubital fossa. Then an ARM consisting of a standardized gas insufflation to reach a plateau of 30 cmH2O for 30 s was performed before skin incision. Invasive mean arterial pressure (MAP), pulse pressure, heart rate, CVP, PVP, pulse pressure variation (PPV), and stroke volume index (SVI) were recorded before ARM (T1), at the end of ARM (T2), before volume expansion (T3), and one minute after volume expansion (T4). Receiver-operating curves (ROC) analysis with the corresponding grey zone approach were performed to assess the ability of ∆PVP (index test) to predict FR, defined as an ≥ 10% increase in SVI following the administration of a 4 ml/kg balanced crystalloid solution over 5 min.Results∆PVP during ARM predicted FR with an area under the ROC curve of 0.76 (95%CI, 0.63 to 0.86). The optimal threshold determined by the Youden Index was a ∆PVP value of 5 mmHg (95%CI, 4 to 6) with a sensitivity of 66% (95%CI, 47 to 81) and a specificity of 82% (95%CI, 63 to 94). The AUC’s for predicting FR were not different between ΔPVP, ΔCVP, and PPV.ConclusionDuring high-risk abdominal surgery, ∆PVP induced by an ARM can moderately predict FR. Nevertheless, other hemodynamic variables did not perform better.

Prognostic Impact of the Get-with-the-Guidelines Heart-Failure Risk Score (GWTG-HF) after Transcatheter Aortic Valve Replacement in Patients with Low-Flow–Low-Gradient Aortic Valve Stenosis

This study examined the prognostic value of the get-with-the-guidelines heart-failure risk score (GWTG-HF) on mortality in patients with low-flow-low-gradient aortic valve stenosis (LFLG-AS) after transcatheter aortic valve implantation (TAVI). Data on feasibility of TAVI and mortality prediction in the LFLG-AS population are scarce. Clinical risk assessment in this particular population is difficult, and a score has not yet been established for this purpose. A total of 212 heart failure (HF) patients with real LFLG-AS were enrolled. Patients were classified into low-risk (n = 108), intermediate-risk (n = 90) and high-risk (n = 14) groups calculated by the GWTG-HF score. Clinical outcomes of cardiovascular events according to Valve Academic Research Consortium (VARC-2) recommendations and composite endpoint of death and hospitalization for heart failure (HHF) were assessed at discharge and 1 year of follow-up. Baseline parameters of the groups showed a median age of 81.0 years [77.0; 84.0] (79.0 vs. 82.0 vs. 86.0, respectively p < 0.001), median EuroSCORE II of 6.6 [4.3; 10.7] (5.5 vs. 7.2 vs. 9.1, p = 0.004) and median indexed stroke volume of 26.7 mL/m2 [22.0; 31.0] (28.2 vs. 25.8 vs. 25.0, p = 0.004). The groups significantly differed at follow-up in terms of all-cause mortality (10.2 vs. 21.1 vs. 28.6%; p < 0.035). There was no difference in intrahospital event rate (VARC). Postprocedural mean gradients were lower in high-risk group (7.0 vs. 7.0 vs. 5.0 mmHg, p = 0.011). No differences in postprocedural aortic valve area (1.9 vs. 1.7 vs. 1.9 cm2, p = 0.518) or rate of device failure (5.6 vs. 6.8 vs. 7.7%, p = 0.731) could be observed. After adjustment for known predictors, the GWTG score (HR 1.07 [1.01-1.14], p = 0.030) as well as pacemaker implantation (HR 3.97 [1.34-11.75], p = 0.013) turned out to be possible predictors for mortality. An increase in stroke volume index (SVI) was, in contrast, protective (HR 0.90 [0.83-0.97]; p = 0.006). The GWTG score may predict mortality after TAVI in LFLG-AS HF patients. Interestingly, all groups showed similar intrahospital event and mortality rates, independent of calculated mortality risk. Low SVI and new conduction disturbances associated with PPI after THV implantation had negative impact on mid-term outcome in post-TAVI HF-patients.

Phenotypes of hemodynamic response to fluid challenge during anesthesia: a cluster analysis.

The fluid challenge (FC) response is usually evaluated as binary, which may be inadequate to describe the complex interactions between heart function and vascular tone response after fluid administration. We applied a clustering approach to assess the different phenotypes of cardiovascular responses to FC administration, considering the associations of all the baseline variables potentially influencing pressure and flow response to a FC. Secondarily, we evaluated the reliability of baseline hemodynamic variables in discriminating fluid responsiveness, which is considered the standard approach at the bedside. Five merged datasets from elective surgical patients receiving a FC dose ≥4 mL/kg, infused over 10 minutes. In a principal component approach, hierarchical clustering was used to define hemodynamic phenotypes of response to FC administration. Hierarchical cluster analysis with Ward linkage was carried out to define similar patient groups using the Gower distance for the mixed combination of continuous and categorical variables. No a priori criteria of fluid responsiveness were applied. The area (AUC) under the pre-FC variables' receiver operating characteristic curves (ROC) was also built to predict fluid responsiveness, defined as SVI ≥10% after FC. We analyzed 223 patients. The cluster analysis identified three hemodynamic clusters of patients: cluster 1 (98 patients, 44.0%) showed an average increase of mean arterial pressure (MAP) and Stroke Volume Index (SVI) of 17.3% (11.9-23.1) and 13.1% (0.5-23.4) at the end of FC, respectively. These patients showed baseline flow and pressure variables slightly below physiological ranges, with high pulse pressure variation (PPV). Cluster 2 (68 patients, 30.5%) showed no increase of MAP and SVI at the end of FC. These patients showed baseline flow and pressure variables within physiological ranges, with low hear rate (HR) and PPV. Cluster 3 (57 patients, 25.5%) showed no MAP increase and an SVI increase of 13.1 (2.1-19.6). These patients showed baseline pressure variables within physiological ranges, low flow variables associated to high HR and PPV. The pulse pressure variation (PPV) showed an AUC of 0.82 (0.03), with a grey zone ranging from 6% to 12%, including 86 (38.5%) patients. Clustering analysis identified three hemodynamic clusters with different response phenotypes to FC. This promising approach may enhance the ability to detect fluid responsiveness at the bedside, by considering the specific association of parameters and not the presence of a single one, such as the PPV. In fact, in our cohort the reliability of the PPV was limited, showing high sensibility and specificity only above 12% and below 6%, respectively, and a grey zone including 38.5% of patients.

Short-term effects of transcatheter aortic valve replacement on blood pressure and cardiac function in elderly patients with severe aortic stenosis.

Transcatheter aortic valve replacement (TAVR) is a standard treatment for elderly and high-risk patients with aortic valve stenosis (AS); however, its short-term effects on blood pressure (BP) and cardiac function are not clear. Therefore, we aimed to determine the short-term effects of TAVR in elderly patients (>75 years), who reflect the clinical situation in Japan. Twenty-eight consecutive elderly patients with severe AS and hypertension who underwent TAVR under general anesthesia were retrospectively investigated. All patients had hypertension that was well controlled with antihypertensive drugs. Serum brain natriuretic peptide level and peak velocity in the aortic valve were significantly reduced. TAVR induces an increase in BP that requires additional antihypertensive agents. There was no correlation between the change rate of SBP and stroke volume index (SVI), but there was a positive correlation between the rate of change in pulse pressure (PP) and SVI. This tendency was particularly observed in patients with low brachial-ankle pulse wave velocity (baPWV). We observed post-TAVR hypertension and required additional antihypertensive drugs. The increases in SVI and PP after TAVR resulted in post-TAVR hypertension. Moreover, post-TAVR hypertension is less likely to occur in elderly patients with a high baPWV, which indicates advanced arteriosclerosis.

Abstract 15165: Dobutamine Stress Echocardiography in Patients With Low Flow, Low Gradient Aortic Stenosis and Preserved Lvef

Introduction: Guidelines recommend the use of Dobutamine stress echocardiography (DSE) in case of low flow low gradient aortic stenosis (LFLG AS) when left ventricular ejection fraction (LVEF) &lt;50%, but few data support this threshold as most studies have tested DSE when LVEF &lt;35%. Hypothesis: To examine the feasibility of DSE in patients with LFLG AS, and the possible interaction between LVEF and accuracy of projected aortic valve area (AVA proj ) in correctly classifying severe AS defined by Cardiac Computer Tomography (C-CT). Methods: Patients with LFLG AS (aortic mean gradient &lt;40 mmHg &amp; AVA &lt;1.0 cm 2 &amp; stroke volume index (SV i ) &lt;35ml/m 2 ) undergoing DSE were identified from two prospective cohorts, and stratified according to LVEF (&lt;35%, 35-50% and &gt;50%). Severe AS was defined as AVC score ≥2000 AU in males, and ≥1200 AU in females on C-CT. Results: Of 214 patients, 65 (30%) presented with LVEF &lt;35%, 58 (27%) with LVEF 35-50%, and 91 (43%) with LVEF &gt;50%. 97 patients presented with severe AS (32 vs 21 vs 44, p=0.26). An inverse relationship was seen between LVEF and left ventricular diameter (60±10mm vs 54±7mm vs 47±6mm, p&lt;0.01). Although resting SV i was different between groups (26.4±6.4mL vs 27.3±5.6 vs 29.6±5.7, p&lt;0.01), no significant differences in SV i change was seen during DSE (7.3±5.9mL vs 5.5±6.2mL vs 6.7±6.7mL, p=0.30), and patients with LVEF &lt;35% were more likely to demonstrate flow-reserve, defined as an increase in SVi &gt;20%; 39 (63%) vs 21 (36%) vs 44 (49%), p=0.01. AVA proj provided similar AUCs (p=0.31) (Figure 1) and cut-off points in classifying severe AS across LVEF groups: LVEF&lt;35%: 1.02 cm 2 /accuracy 74%, vs LVEF 35-50%: 0.82cm 2 /accuracy 72% vs LVEF &gt;50%: 0.9cm 2 /accuracy 65%. Conclusion: DSE leads to similar increases in stroke volume index (SV i ) in patients with LVEF &gt;50% compared with LVEF ≤50%. Furthermore, the projected aortic valve area (AVA proj ) provides good accuracy for identification of true-severe AS, regardless of LVEF stratum.

Carotid doppler indices do not predict fluid responsiveness in mechanically ventilated patients undergoing coronary artery bypass grafting surgery.

This study aimed to determine the predictive value of carotid artery blood flow (CABF), corrected carotid flow time (CFT), and respiratory variation in carotid peak systolic velocity (DVPeakCA) for fluid responsiveness in mechanically ventilated patients undergoing coronary artery bypass grafting (CABG) surgery. It also aimed to correlate each of these indices with changes in stroke volume index (SVI) after a fluid bolus. This prospective, interventional, before-after study recruited 45adult patients undergoing CABG. Following induction of anesthesia, a fluid challenge of 6 ml/kg of a crystalloid solution was delivered over 10 min. Mean arterial pressure (MAP), heart rate (HR), central venous pressure (CVP), CABF, CFT, and DVPeakCA were recorded before and following the intervention. Patients with an increase in SVI of >15% from baseline were considered responders. We had 22 responders and 23 nonresponders. Areas under the receiver operating characteristic (AUROC) curves for the studied indices (CABF, 0.516, CFT, 0.502, and DVPeakCA, 0.671) did not suggest any strong predictive value to detect fluid responsiveness. Similarly, the r values for correlation of these carotid doppler-derived indices, both baseline and as % change from baseline with the % alteration of SVI were all <0.2, which demonstrates a very weak correlation between these variables. Carotid doppler indices are unreliable to assess fluid responsiveness, and cannot replace invasive methods of analyzing preload optimization. There was no significant correlation between carotid doppler-derived indices and alterations in SVI before and after the fluid bolus.

Pressure response to fluid challenge administration in hypotensive surgical patients: a post-hoc pharmacodynamic analysis of five datasets.

In this study weevaluated the effect of fluid challenge (FC) administration in elective surgical patients with low or normal blood pressure. Secondarily, we appraised the pharmacodynamic effect of FC in normotensive and hypotensive patients. We assessed five merged datasets of patients with a baseline mean arterial pressure (MAP) above or below 65mmHg and assessed the changes of systolic, diastolic, mean and dicrotic arterial pressures, dynamic indexes of fluid responsiveness and arterial elastance over a 10-min infusion. The hemodynamic effect was assessed by considering the net area under the curve (AUC), the maximal percentage difference from baseline (dmax), the time when the maximal value was observed (tmax) and change from baseline at 5-min (d5) after FC end. A stroke volume index increase > 10% with respect to the baseline value after FC administration indicated fluid response. Two hundred-seventeen patients were analysed [102 (47.0%) fluid responders]. On average, FC restored a MAP [Formula: see text] 65mmHg after 5min. The AUCs and the dmax of pressure variables and arterial elastance of hypotensive patients were all significantly greater than normotensive patients. Pressure variables and arterial elastance changes in the hypotensive group were all significantly higher at d5 as compared to the normotensive group. In hypotensive patients, FC restores a MAP [Formula: see text] 65mmHg after 5min from infusion start. The hemodynamic profile of FC in hypotensive and normotensive patients is different; both the magnitude of pressure augmentation and duration is greater in the hypotensive group.

Corrected flow time and respirophasic variation in blood flow peak velocity of radial artery predict fluid responsiveness in gynecological surgical patients with mechanical ventilation

BackgroundRecent evidence suggests that ultrasound measurements of carotid and brachial artery corrected flow time (FTc) and respirophasic variation in blood flow peak velocity (ΔVpeak) are valuable for predicting fluid responsiveness in mechanical ventilated patients. We performed the study to reveal the performance of ultrasonic measurements of radial artery FTc and ΔVpeak for predicting fluid responsiveness in mechanical ventilated patients undergoing gynecological surgery.MethodsA total of eighty mechanical ventilated patients were enrolled. Radial artery FTc and ΔVpeak, and non-invasive pulse pressure variation (PPV) were measured before and after fluid challenge. Fluid responsiveness was defined as an increase in stroke volume index (SVI) of 15% or more after the fluid challenge. Multivariate logistic regression analyses and receiver operating characteristic (ROC) curve were used to screen multivariate predictors of fluid responsiveness and identify the predictive abilitie of non-invasive PPV, ΔVpeak and FTc on fluid responsiveness.ResultsForty-four (55%) patients were fluid responders. Multivariate logistic regression analysis showed that radial artery FTc, ΔVpeak, and non-invasive PPV were the independent predictors of fluid responsiveness, with odds ratios of 1.152 [95% confidence interval (CI) 1.045 to 1.270], 0.581 (95% CI 0.403 to 0.839), and 0.361 (95% CI, 0.193 to 0.676), respectively. The area under the ROC curve of fluid responsiveness predicted by FTC was 0.802 (95% CI, 0.706–0.898), and ΔVpeak was 0.812 (95% CI, 0.091–0.286), which were comparable with non-invasive PPV (0.846, 95%CI, 0.070–0.238). The optimal cut-off values of FTc for fluid responsiveness was 336.6 ms (sensitivity of 75.3%; specificity of 75.9%), ΔVpeak was 14.2% (sensitivity of 88.2%; specificity of 67.9%). The grey zone for FTc was 313.5–336.6 ms and included 40 (50%) of the patients, ΔVpeak was 12.2–16.5% and included 37(46%) of the patients.ConclusionsUltrasound measurement of radial artery FTc and ΔVpeak are the feasible and reliable methods for predicting fluid responsiveness in mechanically ventilated patients.Trial registrationThe trial was registered at the Chinese Clinical Trial Registry (ChiCTR)(www.chictr.org), registration number ChiCTR2000040941.

Passive Leg Raise Stress Echocardiography in Severe Paradoxical Low-Flow, Low-Gradient Aortic Stenosis

Dobutamine stress echocardiography is used to increase transvalvular flow in patients with low-flow, low-gradient aortic stenosis (AS). Dobutamine fails to increase the stroke volume index (SVI) in one third of patients. The aim of this study was to test whether passive leg raise (PLR) added to dobutamine could increase SVI and transvalvular flow in patients with severe paradoxical low-flow, low-gradient AS. Forty-five patients with apparent severe low-flow, low-gradient AS on the basis of traditional measurements were included. Twenty-five were categorized as belonging to the paradox group (left ventricular ejection fraction [EF]≥50%) and 20 to the low EF group (left ventricular EF&lt;50% or "classical" low-flow, low-gradient AS) for comparison. A four-step stress echocardiographic examination was performed: resting conditions (rest), PLR alone (PLR), maximal dobutamine infusion rate (Dmax), and a combination of Dmax and PLR (Dmax+PLR). Aortic valve area, SVI, and mean transvalvular flow were calculated using both the velocity-time integral (VTI) of left ventricular outflow tract and the Simpson method. Changes compared with rest and between the stress maneuvers were analyzed. In the paradox group, compared with rest, left ventricular end-diastolic volume was significantly decreased with Dmax but was completely restored with Dmax+PLR (rest vs Dmax vs Dmax+PLR: 61±15 vs 49±18mL [P&lt;.001] vs 61±18mL [P= NS]). The smallest increase in SVI in the paradox group was observed during Dmax (PLR vs Dmax vs Dmax+PLR: VTI, 38±4mL/m² [P&lt;.001] vs 36±7mL/m² [P=.019] vs 41±7mL/m² [P&lt;.001]; Simpson, 28±6mL/m² [P&lt;.001], 21±7mL/m² [P= NS], 27±7mL/m² [P= NS]). Compared with Dmax, Dmax+PLR was able to achieve a higher SVI (VTI, 36±7 vs 41±7mL/m² [P&lt;.001]; Simpson, 21±7 vs 27±7mL/m² [P&lt;.001]) and transvalvular flow with the Simpson method only (179±56 vs 219±56mL/sec, P&lt;.001), as well as a higher mean gradient (34±10 vs 39±12mm Hg, P=.003) and AVA with the Simpson method (0.64±0.21 vs 0.73±0.21cm², P=.026). In the low EF group, only SVI VTI (31±8 vs 35±7mL/m², P=.034) and mean gradient (29±12 vs 34±14mm Hg, P=.003) were higher with Dmax+PLR. The proportion of patients with SVI VTI ≥ 35mL/m² and increases of SVI VTI of &gt;20% compared with rest was highest with Dmax+PLR in both groups. Dobutamine decreases preload in paradoxical low-flow, low-gradient AS. Adding PLR counteracts this effect, resulting in increased SVI and flow (in one method). The combined stress maneuver allowed reclassification of some patients from severe to moderate AS and may therefore be useful in selected cases in this population in which severity is uncertain.

Hemodynamic changes during aortic valve surgery among patients with aortic stenosis

Introduction. Patients with severe aortic stenosis (AS) undergoing surgery are at increased risk of hypotension and hypoperfusion. Although treatable with inotropic agents or fluid, little is known about how these therapies affect central hemodynamics in AS patients under general anesthesia. We measured changes in central hemodynamics after dobutamine infusion and fluid bolus among patients with severe AS and associated these changes with preoperative echocardiography. Methods. We included 33 patients with severe AS undergoing surgical AVR. After induction of general anesthesia, hemodynamic measurements were obtained with a pulmonary artery catheter, including Cardiac index (CI), stroke volume index (SVi) and pulmonary capillary wedge pressure (PCWP). Measurements were repeated during dobutamine infusion, after fluid bolus and lastly after sternotomy. Results. General anesthesia resulted in a decrease in CI and SVi compared to preoperative values. During dobutamine infusion CI increased but mean SVi did not (38 ± 12 vs 37 ± 13 ml/m2, p = .90). Higher EF and SVi before surgery and a larger decrease in SVi after induction of general anesthesia were associated with an increase in SVi during dobutamine infusion. After fluid bolus both CI, SVi (48 ± 12 vs 37 ± 13 ml/min/m2, p < .0001) and PCWP increased. PCWP increased mostly among patients with a larger LA volume index. Conclusion. In patients with AS, CI can be increased with both dobutamine and fluid during surgery. Dobutamine’s effect on SVI was highly variable and associated with baseline LVEF, and an increase in CI was mostly driven by an increase in heart rate. Fluid increased SVi at the cost of an increase in PCWP.

Study of cardiovascular dysfunction in chronic liver disease in a tertiary care hospital in eastern India

Background: Chronic liver disease (CLD) exhibits characteristic hemodynamic changes along with pathological changes in the myocardium. Compensated by the decreased systemic vascular resistance, overt heart failure is usually not seen, and thus cardiac pathology is frequently overlooked. Aims and Objectives: The objectives of the study were to study the presence, types, and severity of cardiovascular (CV) dysfunction in patients of CLD. Materials and Methods: An observational cross-sectional study on 50 patients of CLD at Calcutta National Medical College and Hospital, with all relevant investigations. Results: Out of a sample of 50 patients, of which 14.3% were mild, 34.3% moderate and 51.4% severe CLD (by Child-Pugh Class), 28.6% had a high normal heart rate (90 to 100/min), 45.7% had increased stroke volume index, and 42.9% increased cardiac index, reflecting hyperdynamic circulation. In 42% cases, left ventricular ejection fraction was increased more than 65%, reflecting hyperdynamic circulation, but decreased &lt;55% in 23% cases, which may be an indicator of cirrhotic cardiomyopathy. Ejection fraction is significantly (P=0.016) increased after paracentesis in 33.3% patients, reflecting the mechanical effect of ascites on cardiac function. Diastolic dysfunction was present in 60% (P=0.012) and left ventricular mass index was increased in 45.7% cases. All the parameters correlated with increasing Child-Pugh Class severity of CLD. Conclusion: A high level of awareness is needed to take into account the presence of CV dysfunction and cirrhotic cardiomyopathy in patients of CLD and predict the risk of adverse cardiac events. Specific treatment modalities need further study to improve prognosis in these patients.

Effects of different crystalloid resuscitation on renal function in septic shock rabbits under the guidance of pulse indicator continuous cardiac output

To study the effect of different crystalloid resuscitation on renal function in septic shock rabbits, and to provide a theoretical basis for the choice of crystalloid for clinical fluid resuscitation. Thirty-six healthy male New Zealand white rabbits were divided into six groups by random number table: control group, model group, and four crystalloid groups including normal saline (NS) group, lactate Ringer solution (LR) group, acetate Ringer solution (AR) group, and sodium potassium magnesium calcium glucose injection (SPMCG) group, with 6 rabbits in each group. Rabbits were infused with Escherichia coli lipopolysaccharide (LPS) 500 μg/kg via the marginal ear vein (infused at a constant speed within 20 minutes), and then continued to infuse in an increase of 300 μg/kg every 10 minutes, the maximum dose was 2 mg/kg, until the mean arterial pressure (MAP) dropped to 60% of the basal value, the septic shock model was considered to be successfully reproduced. The rabbits in the control group were not injected with LPS, and other operations were the same as in the model group. Different crystalloid groups were given crystal solution immediately after modeling for resuscitation (predetermined fluid volume 60 mL/kg, transfusion within 3 hours). The volume stress test was performed every hour to guide the fluid volume, and the stroke volume index increase rate (ΔSVI) < 15% was the end point of resuscitation. The control group and the model group were given NS 4 mL×kg-1×h-1 to maintain the physiological requirement. All groups were given tracheotomy and mechanical ventilation, and the hemodynamic changes were monitored by pulse-indicated continuous cardiac output (PiCCO). The dynamic changes of hemodynamic indexes, arterial blood gas analysis, electrolytes, blood glucose and renal function biomarkers were monitored before modeling, immediately after modeling and 3, 6, and 12 hours after resuscitation. (1) Hemodynamic indicators: after modeling, the MAP in the model group and the four fluid resuscitation groups decreased significantly, the cardiac index (CI) increased, and the systemic vascular resistance index (SVRI), global end-diastolic volumn index (GEDVI) decreased. After different crystalloid resuscitation at different time points, MAP, SVRI, and GEDVI increased in the four crystalloid groups. (2) Arterial blood gas analysis, electrolytes, blood glucose: blood lactic acid (Lac) in the model group and the four fluid resuscitation groups increased after model success. After fluid resuscitation, the Lac of each crystalloid group began to decrease and reached to the lowest at 12 hours. Compared with the LR, AR and SPMCG groups, the pH value decreased in the NS group at 6 hours and 12 hours of fluid resuscitation (6 hours: 7.29±0.00 vs. 7.40±0.02, 7.35±0.02, 7.37±0.02; 12 hours: 7.27±0.02 vs. 7.38±0.02, 7.39±0.02, 7.35±0.01; all P < 0.05). After fluid resuscitation, blood Cl- levels at 3, 6, and 12 hours in the NS group were significantly higher than those in the LR, AR and SPMCG groups (mmol/L: 113.4±0.6 vs. 101.4±3.6, 108.0±1.1, 106.0±0.8 at 3 hours; 115.1±2.0 vs. 101.1±2.7, 109.0±2.2, 105.3±0.6 at 6 hours; 116.9±0.1 vs. 104.2±4.4, 107.6±1.7, 108.7±0.6 at 12 hours; all P < 0.05). There was no significant difference in blood glucose at each time point among the four crystalloid groups. (3) Biomarkers of renal function: blood and urine neutrophil gelatinase associated lipocalin (NGAL) and cystatin C (Cys C) were significantly increased in the model group and four fluid resuscitation groups. After fluid resuscitation, blood, urine NGAL and Cys C decreased. There was no significant difference in blood, urine NGAL and Cys C at all the time points among the different fluid resuscitation groups. In the rabbit model of septic shock induced by Escherichia coli LPS, hyperchloremia and acidosis occurred after NS resucitation, but did not occur during the recovery of LR, AR and SPMCG. There was no difference in the effects of different crystalloid resuscitation on renal function in septic shock rabbits.