LVOT VTI Research Articles

High Central Venous Pressure and Right Ventricle Size Are Related to Non-decreased Left Ventricle Stroke Volume After Negative Fluid Balance in Critically Ill Patients: A Single Prospective Observational Study.

Background: Optimal adjustment of cardiac preload is essential for improving left ventricle stroke volume (LVSV) and tissue perfusion. Changes in LVSV caused by central venous pressure (CVP) are the most important concerns in the treatment of critically ill patients.Objectives: This study aimed to clarify the changes in LVSV after negative fluid balance in patients with elevated CVP, and to elucidate the relationship between the parameters of right ventricle (RV) filling state and LVSV changes.Methods: This prospective cohort study included patients with high central venous pressure (CVP) (≥8 mmHg) within 24 h of ICU admission in the Critical Medicine Department of Peking Union Medical College Hospital. Patients were classified into two groups based on the LVSV changes after negative fluid balance. The cutoff value was 10%. The hemodynamic and echo parameters of the two groups were recorded at baseline and after negative fluid balance.Results: A total of 71 patients included in this study. Forty in VI Group (LVOT VTI increased ≥10%) and 31 in VNI Group (LVOT VTI increased <10%). Of all patients, 56.3% showed increased LVSV after negative fluid balance. In terms of hemodynamic parameters at T0, patients in VI Group had a higher CVP (p < 0.001) and P(v-a)CO2 (p < 0.001) and lower ScVO2 (p < 0.001) relative to VNI Group, regarding the echo parameters at T0, the RVD/LVD ratio (p < 0.001), DIVC end−expiratory (p < 0.001), and ΔLVOT VTI (p < 0.001) were higher, while T0 LVOT VTI (p < 0.001) was lower, in VI Group patients. The multifactor logistic regression analysis suggested that a high CVP and RVD/LVD ratio ≥0.6 were significant associated with LVSV increase after negative fluid balance in critically patients. The AUC of CVP was 0.894. A CVP >10.5 mmHg provided a sensitivity of 87.5% and a specificity of 77.4%. The AUC of CVP combined with the RVD/LVD ratio ≥0.6 was 0.926, which provided a sensitivity of 92.6% and a specificity of 80.4%.Conclusion: High CVP and RVD/LVD ratio ≥0.6 were significant associated with RV stressed in critically patients. Negative fluid balance will not always lead to a decrease, even an increase, in LVSV in these patients.

Assessment of Left Ventricular Outflow Tract Velocity Time Integral in Pediatric Patients with Vasovagal Syncope

Background Syncope is an important and common clinical condition, and the neurally mediated syncope is the most frequent type of syncope. Head up tilt testing is considered as a first line diagnostic test. The aim of this study was to assess the left ventricular outflow tract velocity time integral in echocardiography of pediatric patients with vasovagal syncope. Materials and Methods: In this case-control study, between January 2019 and December 2020 92 patients who referred in in Mofid Children Hospital in Tehran, Iran, for vasovagal syncope in the case group and 92 healthy children with maximum matching of sex and age in the control group were included in the study. Demographic, clinical and para-clinical data were recorded for each patient in the respective checklists, and HUTT and echocardiography were reviewed, then the results of two groups were compared. Results: The mean age of the patients with vasovagal syncope was 12.12 ±5.18 years. 66.3% of patients in the case group were female. There was a statistically significant relationship between LVOT-VTI and positive result of HUTT (p <0.001). There was no relationship between LVOT VTI in case and control groups (p=0.14). Conclusion The mean LVOT VTI index in patients with negative tilt test is higher than patients with positive tilt test. Although echocardiographic indices in children with vasovagal syncope are in normal range, accurate measurement of LVOT-VTI can be helpful in predicting a positive HUTT result.

A Practical Risk Score for Prediction of Early Readmission after a First Episode of Acute Heart Failure with Preserved Ejection Fraction.

Background: The first admission for acute heart failure with preserved ejection fraction (HFpEF) drastically influences the short-term prognosis. Baseline characteristics may predict repeat hospitalization or death in these patients. Methods: A 103 patient-cohort, admitted for the first acute HFpEF episode, was monitored for six months. Baseline characteristics were recorded and their relation to the primary outcome of heart failure readmission (HFR) and secondary outcome of all-cause mortality was assessed. Results: We identified six independent determinants for HFR: estimated glomerular filtration rate (eGFR) (p = 0.07), hemoglobin (p = 0.04), left ventricle end-diastolic diameter (LVEDD) (p = 0.07), E/e’ ratio (p = 0.004), left ventricle outflow tract velocity-time integral (LVOT VTI) (p = 0.045), and diabetes mellitus (p = 0.06). Three of the variables were used to generate a risk score for HFR: LVEDD, E/e’, LVOT VTI -DEI Score = − 28.763 + 4.558 × log (LVEDD (mm)) + 1.961 × log (E/e’ ratio) + 1.759 × log (LVOT VTI (cm)). Our model predicts a relative amount of 20.50% of HFR during the first 6 months after the first acute hospitalization within the general population with HFpEF with a DEI Score over −0.747. Conclusions: We have identified three echocardiographic parameters (LVEDD, E/e’, and LVOT VTI) that predict HFR following an initial acute HFpEF hospitalization. The prognostic DEI score demonstrated good accuracy.

A multicentric quality-control study of exercise Doppler echocardiography of the right heart and the pulmonary circulation. The RIGHT Heart International NETwork (RIGHT-NET)

PurposeThis study was a quality-control study of resting and exercise Doppler echocardiography (EDE) variables measured by 19 echocardiography laboratories with proven experience participating in the RIGHT Heart International NETwork.MethodsAll participating investigators reported the requested variables from ten randomly selected exercise stress tests. Intraclass correlation coefficients (ICC) were calculated to evaluate the inter-observer agreement with the core laboratory. Inter-observer variability of resting and peak exercise tricuspid regurgitation velocity (TRV), right ventricular outflow tract acceleration time (RVOT Act), tricuspid annular plane systolic excursion (TAPSE), tissue Doppler tricuspid lateral annular systolic velocity (S’), right ventricular fractional area change (RV FAC), left ventricular outflow tract velocity time integral (LVOT VTI), mitral inflow pulsed wave Doppler velocity (E), diastolic mitral annular velocity by TDI (e’) and left ventricular ejection fraction (LVEF) were measured.ResultsThe accuracy of 19 investigators for all variables ranged from 99.7 to 100%. ICC was > 0.90 for all observers. Inter-observer variability for resting and exercise variables was for TRV = 3.8 to 2.4%, E = 5.7 to 8.3%, e’ = 6 to 6.5%, RVOT Act = 9.7 to 12, LVOT VTI = 7.4 to 9.6%, S’ = 2.9 to 2.9% and TAPSE = 5.3 to 8%. Moderate inter-observer variability was found for resting and peak exercise RV FAC (15 to 16%). LVEF revealed lower resting and peak exercise variability of 7.6 and 9%.ConclusionsWhen performed in expert centers EDE is a reproducible tool for the assessment of the right heart and the pulmonary circulation.

Usefullness of peak mitral regurgitation velocity to left ventricular outflow tract time velocity integral ratio as a new prognostic marker for one year and long term mortality in failing heart

Abstract Background and aim Systemic vascular resistance (SVR) is useful for risk estimation and therapy guidance in HF. It has been showed that the ratio of peak mitral regurgitation velocity (MRV) to left ventricular outflow tract velocity-time integral (LVOT VTI) correlated positively with SVR. We aimed to assess the association of MRV/LVOT VTI ratio with established prognostic markers and its prognostic role for predicting one year and long term composite end-points in patients with HF and reduced ejection fraction (HFrEF). Material and methods We prospectively enrolled a total of 72 patients with HFrEF and 10 control subjects. Patients were followed up patients for median 40.5 months. Primary composite endpoint (CEP) was defined as any of these outcomes including requiring mechanical circulatory support, cardiac transplantation and all-cause mortality. Results CEP(+) patients had higher MRV/LVOT VTI ratio than others (0.48±0.15 vs. 0.39±0.18 p=0.012). MRV/LVOT VTI ratio was positively correlated with functional status (β=0.539, p=0&amp;lt;001), serum BNP level (β=0.479, p&amp;lt;0.001),troponin I (β=0.415, p&amp;lt;0.001), and Uric acid level (β=0.235 p=0.018) and negatively correlated with SEATTLE score derived life expectancy (β=−0.248, p=0.032). Adjusted with other parameters, every 0.1 increase in MRV/LVOT VTI ratio increased the one-year CEP risk by 27% and long-term CEP risk by 24.6%. In Kaplan Meier analysis, patients with MRV/LVOTVTI ratio ≥0.39 had more long-term CEP compared to others. Conclusion MRV/LVOT VTI ratio seemed to be useful predictor of poor prognosis associated with other established HF prognostic markers. Figure 1 Funding Acknowledgement Type of funding source: None

Left heart Impella-device to bridge acute mitral regurgitation to MitraClip-procedure: a novel implementation of percutaneous mechanical circulatory support

Abstract Background Acute mitral regurgitation (MR) is an emergency, often requiring urgent surgery. Severe acute MR presenting with hemodynamic collapse is usually caused by papillary muscle rupture or dysfunction after acute myocardial infarction (AMI) or chordal rupture, resulting in flail mitral leaflet(s). Preoperative stabilization is complex due to concomitant hemodynamic collapse and hypoxic respiratory failure. Finding the right balance between both preload and inotropic support is challenging. When patients are too sick for immediate surgical intervention, mechanical circulatory support can be considered because of its ability to both unload and reduce of cardiac work while increasing coronary perfusion and cardiac output. Nevertheless, even after initial stabilization, surgical risk remains high in critically ill acute severe MR patients and transcatheter treatments such as MitraClip are increasingly being explored. Methods Between August 2017 and September 2019, patients presenting with acute severe mitral regurgitation and considered too ill for immediate surgical intervention (EURO-II score &amp;gt;11.2% plus pulmonary oedema necessitating mechanical ventilation and/or hemodynamic instability), were selected for an Impella-assisted LV unloading technique as bridge to MitraClip-procedure. Five patients were selected for the combined left Impella/MitraClip-procedure in two tertiary cardiac ICUs. Results The mean age was 72 years. The cause of MR was ischemic in 20% and all patients presented in cardiogenic shock state, necessitating mechanical ventilation. The overall cardiac operative risk assessment (Euro-II) score predicted a 35% chance of in-hospital mortality. Cardiac output was severely impaired (mean LVOT VTI 8.2 cm). All patients were on inotropic support and supported by an Impella-CP pVAD (mean flow 2.5 Liter per minute; mean 6.3 days of support). In all cases, we managed to reduce the LVEDP below 15 mmHg using the combination of medical therapy (afterload reduction, inotropes), mechanical ventilation and pVAD-therapy. The MR was significantly reduced by a MitraClip-procedure in each Impella supported patient. The overall survival at discharge was 80%. One patient with late referral and multiple organ failure at presentation deceased due to refractory cardiogenic shock. Overall, severe MR was reduced to grade 1+ and all four patients survived 6 months after discharge with only one readmission for decompensated heart failure. Conclusions A combined strategy of Impella and MitraClip appears to be a novel, feasible alternative for patients presenting with acute, severe MR unable to proceed to a corrective surgical procedure at presentation due to severe left ventricular forward flow failure. In these cases, the early initiation of pVAD-support may reduce the risk of development of irreversible end- organ damage and dysfunction. Exploration in a larger, randomised population is warranted to investigate this strategy further. Funding Acknowledgement Type of funding source: None

Non-invasive Hemodynamic Monitoring of Fluid Resuscitation in Cirrhotic Patients with Acute Kidney Injury

BACKGROUND: Fluid management of patients with liver cirrhosis and acute kidney injury (AKI) is a complex problem requiring accurate assessment of the intravascular volume status and the cause of the AKI. Echocardiography used in various hemodynamic monitoring as a quick, easy, bedside, and non-invasive tool with great sensitivity.&#x0D; AIM: This study aims to evaluate echocardiography as a non-invasive hemodynamic monitoring tool for the assessment of volume status and cardiac function before and after volume expansion in patients with liver cirrhosis presented by AKI.&#x0D; PATIENTS AND METHODS: This study included 120 patients with liver cirrhosis and AKI. All patients were subjected to clinical evaluation, laboratory assessment of kidney and liver functions, and echocardiographic assessment of inferior vena cava (IVC) collapsibility index, left ventricular outflow tract velocity time integral (LVOT VTI) variability index, and cardiac output (CO).&#x0D; RESULTS: Comparison between responders and non-responders to volume resuscitation regarding the echocardiographic data showed that responders had significantly higher IVC collapsibility index, LVOT VTI variability index, and % of CO increase. IVC collapsibility index and LVOT VTI variability index showed good predictive value of fluid responsiveness.&#x0D; CONCLUSIONS: The use of echocardiography is a good tool for hemodynamic monitoring of fluid resuscitation in cirrhotic patients with AKI. The use of echocardiography has limited the use of central venous line only to patients with hemodynamic instability requiring vasoactive support.

1234 Constrictive Pericarditis, an unlikely cause of Central Sleep Apnea

Abstract Introduction Central sleep apnea (CSA) and Cheyne stokes respiration (CSR) is a well-recognized complication of heart failure across multiple New York Heart Association functional classes. We present a case of CSA associated with constrictive pericarditis and normal systolic function. Report of Case 43-year-old male with past medical history of severe obstructive sleep apnea noted to have high residual apnea-hypopnea index (AHi) while using automatic continuous positive airway pressure, suspected to be central events. The patient also had progressive dyspnea on exertion, chest pain, and bilateral transudative pleural effusions. Pulmonary function testing was normal. He underwent a split night PSG which demonstrated severe OSA with AHi 81/hour during baseline. With CPAP titration, AHi was 30/hr, with predominately central events. Transthoracic echocardiogram demonstrated reduced stroke volume (LVOT VTI .085), dilated IVC, and EF 55%, septa! bounce, and annulus reversus (possible constriction). Right and left heart catheterization showed equalization of the diastolic pressures (RA 35 mm Hg, RV 48/30, PA 49/30, PCWP 29, Cl 1.6, SVR 1118 dynes, PVR 216 dynes), no coronary disease, and codominant system. Technetium 99 pyrophosphate scan demonstrated symmetric uptake in left and right ventricles, but abnormal thickening of pericardium suspicious for constrictive pericarditis. His symptoms progressed despite aggressive medical therapy and he was ultimately taken to surgery for pericardiectomy where it was noted his pericardium was extremely thickened and densely adhered to the myocardium, consistent with constrictive pericarditis. There was immediate improvement in hemodynamic status post-operatively. At post discharge follow up, he was NYHA class I, with resolution of all signs of heart failure. Repeat polysomnogram demonstrated persistent OSA, but resolution of CSA at baseline and with CPAP. Conclusion Constrictive pericarditis has not previously been reported as a cause of CSA or CSR. This patient had complete resolution of his heart failure symptoms with definitive resection of his pericardium.

Prospective investigation of immunotherapy-induced fatigue by rest and stress echocardiography.

e24060 Background: Immune checkpoint inhibitors (ICI) effect durable responses in cancer patients (pts). Myocarditis is rare but fatigue is commonly reported, and whether ICI-induced fatigue is due to subclinical cardiac toxicity is unknown. We hypothesized that pts on ICI develop changes on rest and stress echocardiogram (echo) that correlate with fatigue. Methods: A prospective observational study was performed to monitor cardiac function in pts receiving ICI. Our cohort consisted of pts (n = 10) with stage III/IV melanoma, ECOG 0-1, deemed safe to exercise, without unstable cardiac symptoms. ICI-naïve pts received anti-PD1 alone or in combination with anti-CTLA-4, in adjuvant or metastatic setting. Rest transthoracic echo and dynamic staged exercise stress echo testing was conducted at baseline (prior to ICI) and at 3 and 6 months (mo) following ICI. Various echo parameters at rest and stress were compared. irAEs were detailed and surveys administered at baseline and post-follow up. Results: 10 pts (9 men, mean age 56 yrs) completed baseline cardiac testing of whom 7 completed follow up testing at 6 mo (6 anti-PD1 monotherapy, 1 metastatic combination therapy). Of these 7 pts, 5 (71%) reported increased fatigue per CTCAE at 3 or 6 mo follow up and all 7 had irAEs (3 rash, 1 colitis, 1 diarrhea, 1 hypophysitis, 1 arthralgia, 1 xerostomia). Among resting echo parameters, left ventricular outflow tract velocity time integral (LVOT VTI) was significantly reduced at 6 mo compared to baseline (22.6 ± 3.4 vs 20.0 ± 2.5, p = 0.0047), albeit still within normal range. No other resting echo parameters changed. Among exercise echo parameters, there was no difference in METs achieved, time of exercise, blood pressure or heart rate between time points. Of note, of 7 subjects who completed 6 mo testing, 2 (29%) were unable to achieve previous peak stage of exercise during testing. Conclusions: Though no echo parameter significantly correlating with fatigue was reported, nearly one-third of a small cohort of pts were unable to achieve peak exercise 6 mo after starting ICI. This combined with the statistical reduction in LVOT VTI suggests functional limitation and warrants further study. Post-follow up surveys are pending and may further inform issues important in ICI survivorship. [Table: see text]

QRS Duration as a Predictor of Left Ventricular Outflow Tract Velocity Time Integral in Patient with Cardiac Resynchronization Therapy.

Background:Cardiac resynchronization therapy (CRT) has a morbidity and mortality benefits in moderate to severe heart failure. It reduces mortality and hospitalization and improves cardiac function. It can be used according to the European guidelines in severely depressed left ventricular ejection fraction (i.e., ≤35%) and complete left bundle branch block. However, 30% of patients may show no benefit from CRT therapy. Therefore, prediction of CRT response seems to be an important subject for study in the current researches. We aimed to study the correlation between Surface ECG QRS complex duration (QRS) duration and cardiac output measured by ventricular outflow tract velocity time integral (LVOT VTI) as a predictor of response in patients with CRT implantation.Methods:We studied 100 consecutive patients prospectively with biventricular pacing system. The patients were studied at the pacemaker follow-up clinic. Each patient was subjected to: Full medical history, general and local examination, a 12 lead electrocardiogram and QRS duration in ms was measured. All patients were subjected to a focused transthoracic echocardiographic examination in which a parasternal long axis view was obtained to measure the diameter of the LVOT diameter in mid-systole. The LVOT VTI was measured by pulsed-wave Doppler in the LVOT using a 2-mm sample volume positioned just proximal to the aortic valve in the apical five chamber view.Results:We found a statistically significant difference between CRT responders and nonresponders as regards age, body surface area (BSA), time since CRT implantation and smoking status (P = 0.018, 0.039, 0.002, <0.001). There was negative significant correlation between QRS duration and LVOT VTI and stroke volume index. The optimal cut off values for optimal response to CRT using receiver operating characteristics curves were 130 ms for postimplant QRS duration and 17.1 cm for LVOT VTI. We also found a significant difference between responders and nonresponders as regard CO. It was higher in responders (5.97 vs. 3.34, P < 0.001).Conclusion:CRT response is more in patients with lower BSA, and without previous history of ischemic heart disease or smoking. There is a significant negative correlation between QRS duration and LVOT VTI.

Study on Image Acquisition of Transthoracic Echocardiography in Mechanically Ventilated ICU Patients

Objective This study aimed to determine which parameters in transthoracic echocardiography (TTE) are more likely to be affected when applied in a critical care setting with mechanical ventilation.Methods Ninety mechanically ventilated ICU patients were enrolled into the study group. The control group consisted of 90 patients who underwent interventional therapy. All patients had bedside TTE for parametric measurements including the right ventricular size, septal kinetics and left ventricular ejection fraction (LVEF) by eyeballing (visual assessment), the tricuspid annular plane systolic excursion (TAPSE), mitral annular plane systolic excursion (MAPSE) by M-mode sonography, the right ventricular outflow tract velocity-time integral (RVOT VTI) and left ventricular outflow tract velocity-time integral (LVOT VTI) by pulse-Doppler, the right ventricular fraction of area change (FAC) and left ventricular ejection fraction (LVEF Simpson) by endocardium tracing. We compared the differences in the frequency of optimal image acquisition in assessments of these parameters between the two groups, as well as the differences in acquisition rates of parameter measurements in ventilated ICU patients.Results There were significantly fewer patients in the study group than in the control group who had optimal images acquisitions for parameter assessments with M-mode method, pulse Doppler method and endocardium-tracing method (P<0.05); no significant difference was obsered in the number of patients with optimal images for RV eyeballing and LVEF eyeballing between the two groups. In the study group, significantly fewer optimal images were acquired for FAC than for TAPSE (22.2% vs. 72.2%, χ2=45.139, P<0.001) and RVOT VTI (22.2% vs. 71.1%, χ2=43.214, P<0.001); there were also fewer optimal images acquired for LVEF Simpson than for MAPSE (37.8% vs. 84.4%, χ2=41.236, P<0.001) and LVOT VTI (37.8% vs. 85.6%, χ2=43.455, P<0.001).Conclusions Images acquisition of optimal TTE images tend to be difficult in mechanically ventilated ICU patients, but eyeballing method for functional evaluation could be an alternative method. For quantitative parameters measurements, M-mode based longitudinal function evaluation and pulse Doppler-based VTI were superior to the endocardium-tracing based parameter assessments.

107 Low-flow low-gradient aortic stenosis: aortic valve area estimated by continuity equation versus simplified method of projected aortic valve area

Abstract Introduction The evaluation of real severity of "low-flow low-gradient" aortic stenosis (LFLG AS) is particularly challenging. TOPAS study demonstrated that projected aortic valve area at a normal transvalvular flow rate (AVAproj) derived from dobutamine stress echocardiography (DSE) is superior to the traditional Doppler indices to discriminate true severe-AS and pseudosevere-AS. Purpose To compare two echocardiographic methods to estimate severity of LFLG AS with DSE (aortic valve area (AVA) estimated by continuity equation (AVA-CE) and simplified method of AVAproj) in patients (pts) with low transvalvular flow rate (&amp;lt;250mL/seg). Methods Unicentric, retrospective study, that included pts with LFLG AS undergoing DSE with low dose dobutamine protocol, during Nov 2013-Dec 2018 period. Evaluation at rest and peak DSE of vital signs, mean transaortic gradient, aortic VTI, LVOT VTI and VTI ratio, valvulo-arterial impedance (ZVA), AVA-CE, simplified method of AVAproj and global longitudinal strain (GLS). Results A total of 27 DSE were performed in 23 different pts, mean age of 76 ± 8 years, 82% male. At rest 55% in sinus rhythm, mean heart rate (HR) was 76 ± 12 bpm, mean systolic arterial pressure (SAP) was 122 ± 22 mmHg, mean ZVA 4.3 ± 2 mmHg/ml/m2; mean diameter of LVOT was 21,7 ± 2,6cm, mean of mean aortic gradients 21 ± 7 mmHg, 67% of pts had a VTI ratio at rest compatible with severe AS and remaining compatible with moderate AS. Estimated mean AVA-CE was 0.86 ± 0.29 cm2 with 67% of pts classified as severe AS. Mean left ventricular ejection fraction at rest was 31 ± 9%, systolic volume index 28,7 ± 8 mL/m2 and GLS -5,9%. During low dose perfusion protocol of dobutamine 100% patients remained asymptomatic, mean HR was 110 ± 25 bpm, mean SAP was 123 ± 26 mmHg, mean ZVA 3.6 ± 1.7 mmHg/mL/m2, mean of mean aortic gradients 28 ± 9mmHg, 37% of pts presented VTI ratio compatible with severe AS and remaining compatible with moderate AS. Mean flow reserve was 16 ± 16% and mean GLS-7.2%. AVA-CE was 1,06 ± 0,35 cm2 with 56% of pts classified as severe AS and mean projected AVA was 1.01 ± 0.22cm2, without significant difference in AVA estimated by the two methods (p = 0.344). Projected AVA allowed re-classification of AS in 22% of pts (5 patients), with 31% of severe AS reclassified as moderate AS while AVA-CE allowed re-classification in 13% (3 patients), with 19% of severe AS reclassified as moderate AS. Considering medium follow up of 24 months, 6 patients were submitted aortic valve replacement surgery and another 6 patients to transcatheter aortic valve replacement. The simplified projected valve area calculation show no significant therapeutic impact in the selection of this patients. Conclusion The simplified projected valve area calculation is technically feasible and accessible. This study shows a good correlation in pts with low cardiac flow. If AVAproj method had been used 2 extra patients would have been reclassified during DSE.

P1766 Comparison of left ventricular stroke volume in healthy adults among regions around the world: results from the World Alliance of Societies of Echocardiography (WASE) Normal Values Study

Abstract Funding Acknowledgements WASE Normal Values Study is sponsored by American Society Echocardiography Foundation. OnBehalf the WASE Investigators Background The American Society of Echocardiography (ASE) and the European Association of Cardiovascular Imaging (EACVI) chamber quantification guidelines provide normal reference values for a variety of size and function parameters. While used worldwide, these were predominantly obtained from American and European Caucasian populations and may not represent individuals from other regions around the world. Accordingly, ASE in collaboration with its International Alliance Partners conducted the World Alliance of Societies of Echocardiography (WASE) Normal Values Study to establish and compare normal echocardiographic values across races, ethnicities and countries worldwide. While most previous studies focused on left ventricular (LV) size and ejection fraction, LV stroke volume (SV) in healthy normal subjects has not been well defined. In this report, we aim to examine similarities and differences in normal LV SV indexed by body surface area (SVI) among regions around the world. Methods WASE Normal Values Study is a multinational, observational, cross-sectional study. Individuals free from known cardiac, lung and renal disease were prospectively enrolled with even distribution among age groups and gender. Echocardiographic images were acquired following a standardized protocol. LV SV was assessed by Doppler-derived (LVOT diameter and VTI) and two-dimensional (2D) biplane Simpson’s methods. LV SVI was calculated to account for differences in body size. These measurements were analyzed (TOMTEC) in a single core laboratory following ASE/EACVI Guidelines. Results As of May 2019, LV SV has been analyzed in 1164 cases from 13 countries, representing 8 distinct regions worldwide. In this population, age, body surface area and 2D LV ejection fraction were 47 ± 17 years old (range 18-87 years old), 1.76 ± 0.22 m² (range 0.95-2.44 m²) and 63.2 ± 2.9 % (range 52.7-73.7 %), respectively. LV SV and SVI by Doppler were larger than those obtained by 2D method in all regions. LV SV and SVI in both methods had significant differences among regions (p&amp;lt; 0.0001, Kruskal-Wallis test). LV SV and SVI in South Asia (India) were smallest in both methods and were also significantly smaller than other Asian regions (Figure). North America and Europe had largest LV SV and SVI by Doppler method, while Oceania had largest values by 2D. Conclusions The WASE Normal Values Study shows geographical variability in LV SVI across continents and countries. This information should be considered when determining normative values for SV and SVI. Abstract P1766 Figure.

P4382O2-pulse measure obtained by gas exchange analysis is an accurate esteeme of stroke volume?

Abstract Background It is axiomatic that exercise performances depends on cardiac output increase. Among several methods for noninvasively estimating stroke volume, O2 pulse (i.e. the ratio of VO2/HR) is generally used during gas exchange analysis, but its accuracy has never been well investigated. Purpose To test the validity and the accuracy of O2 pulse as a measure of stroke volume (SV) in comparison with the echocardiographic methods. Methods From 22nd of August 2016 to 30th of April 2018 our laboratory performed 259 cardiopulmonary exercise tests (CPET) combined with echo. The group of patients was characterized by a heterogeneous spectrum of diseases: 70 coronary artery disease, 10 heart failure with preserved ejection fraction, 13 heart failure with middle ejection fraction, 26 heart failure with reduced ejection fraction, 29 Fabry disease, 7 hypertrophic cardiomyopathy, 10 dilated cardiomyopathy, 30 aortic stenosis, 16 aortic regurgitation, 8 mitral stenosis, 76 mitral regurgitation, 6 tricuspid regurgitation, 7 congenital heart diseases. The median age was 65 yr (52,5; 74,5) and 61,5% of patients was male. In our group are present 20 healthy subjects with normal heart. O2 pulse was measured at rest, at 2 minutes, 4 minutes, 6 minutes and at maximum of stress. In some cases the maximum of stress correspond to 4- or 6-minutes of stress. All the echocardiographic images were taken with Epiq7C, Philips. The left ventricle SV was measured as SV = LVOT area x LVOT VTI, all the measures and the images where acquired by the same operator to reduce at minimum the external error introduce by the operator. Results As first step we analysed the absolute value of O2-pulse and SV at rest and during the different steps of exercise to see if and how they behave. In the figure attached is possible to see that both the values increased during the exercise with a small reduction at the maximum that may be explained by a premature interruption of the exercise. Secondly we analysed the correlation between O2 pulse and LVOT-SV at rest and during 2-, 4-, 6- minutes of exercise and at maximum which was respectively: r=0,23 (p&lt;0,0001), r=0,36 (p&lt;0,0001), r=0,30 (p&lt;0,0001), r=0,25 (p&lt;0,0001) and r=0,51 (p&lt;0,0001) (see figure 2). The analysis has been possible in 259 patients at rest, in 246 at 2-minutes of stress, in 221 at 4-minutes of stress and in 149 patients at 6-minutes of stress. At maximum of exercise, the analysis has been carried out in 229 patients, but we need to keep in mind that maximum of stress includes both 4- and 6-minutes of exercises according to the capability of each patients. Conclusion In our analysis we show an incremental trend during exercise of O2-Pulse value and of LVOT-SV. At rest and during exercise it is present a good correlation between O2-pulse and LVOT-SV. These data reinforce the concept that O2 pulse reflects an estimation of SV and may explain its reported prognostic validity in prospective studies.

P928Pseudo-discordance mimicking low-flow low-gradient AS in TAVR patients with severe symptomatic aortic stenosis

Abstract Background The combination of a small aortic valve area valve area (AVA) and a low mean gradient (MG) severity pose a serious clinical challenge in the diagnosis of severe aortic stenosis (AS). While this discordance is frequently labeled “low-flow low-gradient AS”, there are two additional potential causes: underestimation of MG and underestimation of AVA. Purpose To investigate prevalence and root causes of discordant echocardiographic findings in symptomatic patients with AS and normal LV function by comparing Doppler data, invasive hemodynamic data, CT LV outflow tract size and calcium score. Methods and results We studied 67 severely symptomatic patients with AS and an LVEF&gt;50%. Thirty patients (45%) had discordant echocardiographic findings (MG&lt;40 mmHg, AVA≤1cm2). Of those, 16 had also discordant findings by invasive measurements (True Discordants), compatible with low-gradient severe AS. In 14, catheterization data were actually concordant and hence discrepant to the echocardiographic findings (False Discordants): In 7 of them, the echocardiographic MG was &gt;35 mmHg; in 5 it was &gt;30 mmHg and only in 2 between 25 and 29 mmHg. In 6 of the 14 patients with underestimated MG, no right parasternal Doppler examination had been performed, LVOT VTI tracings were clearly suboptimal in 3 patients and 1 case was deemed inadequate due to poor imaging quality. LVOT area by echocardiography or by CT could not differentiate between Concordants and Discordants (p=0.3 and p=0.8 respectively) or between True and False Discordants (p=0.5 and p=0.6 respectively). While calcium score was similar in Concordants (2711±1159 AU) and False Discordants (2692±1136AU, p=0.96), it tended to be higher in Concordants (2711±1159 AU), when compared to True Discordants (1906±1284 AU, p=0.07). In patients with concordant echocardiographic findings calcium score levels of &gt;3000 AU in men and &gt;1600 AU in female had a positive predictive value (PPV) of 90% for the correct diagnosis of severe aortic stenosis. In patients with discordant findings the PPV was 80%. Conclusions 1) The majority of severely symptomatic AS patients with normal LV systolic function an echocardiographic AVA≤1.0 cm2 and a MG&gt;30mmHg considered for TAVR have severe AS by calcium score. 2) In this patient population, discordant echocardiographic findings are in about half of the cases due to technical factors (“pseudo-discordance”) rather than due to true low flow low-gradient stenosis. 3) Pseudo-discordance is mainly due to mild-moderate underestimation of gradients, caused by a lack of reliable right parasternal tracings, rather than due to underestimation of valve area due to the echocardiographic circularity assumption in the presence of an elliptical LVOT. 4) The diagnosis of true low-flow AS cannot be established without a clear Doppler tracing from the right parasternal window. 5) Absent an adequate right parasternal window, patients should undergo CT assessment of calcium score.

End Tidal Carbon dioxide can track cardiac output changes during fluid challenge in Shocked Mechanically Ventilated Patients

Background: In this study, we investigated the ability of end tidal carbon dioxide pressure (PETCO2) to monitor the changes in cardiac output (CO) induced by fluid challenge and to predict fluid responsiveness. Patients and Methods: We conducted our study upon 38 shocked patients requiring fluid challenge (FC). Hemodynamic variables, central venous pressure (CVP), End-tidal CO2, arterial and venous blood gas analysis and cardiac output were recorded before and after fluid challenges. Fluid responders were identified when cardiac output increased more than 15% after fluid challenge, cardiac output (CO) was estimated by measuring left ventricular outflow tract velocity-time integral (LVOT VTI) by transthoracic doppler echocardiography. Results: Twenty-one (55.3%) patients were fluid responders. Fluid challenge induced increase in CO and PETCO2 was moderately correlated (r = 0.5; P 0.002). The area under receiver operating characteristic (ROC) curve of Δ PETCO2 was 0.89±0.05 CI (81- 98) with an increase ≥ 3.13% in PETCO2 can predict fluid responsiveness with 85.7% sensitivity and 88.3% specificity. No other clinical or hemodynamic variables can predict fluid responsiveness. The area under ROC curve of ΔCVP was 0.48±0.1 CI (32- 64) with an increase ≥ 2cmH2O in CVP can predict fluid responsiveness with 38% sensitivity and 76.5% specificity. Conclusions: Our findings indicate that induced changes in PETCO2 during fluid challenge could be used to monitor changes in cardiac output (CO) for prediction of fluid responsiveness in mechanically ventilated shocked patients, under stationary minute ventilation and steady CO2 production

Echocardiographic Weaning in Temporary Mechanical Circulatory Support: The Role of LVOT VTI

Purpose With ongoing research, there is still absence of robust evidence-based recommendations describing use and clinical impact of daily echocardiographic evaluation for mechanically unloaded patients supported with either temporary micro-axial flow (Impella) or intra-aortic balloon counterpulsation (IABP) pumps. Our hypothesis is that in such patients, adjunct protocolized bedside echocardiographic weaning evaluation offers a reliable surrogate of myocardial performance prior to explant. Methods Our description included retrospective evaluation of a database of patients supported with Impella (CP/5.0) or IABP at the Baystate Medical Center Cardiac ICU from 2014 to 2017. Patients included had 1) clinical and hemodynamic cardiogenic shock, 2) prolonged Impella/IABP support requiring ICU level of care, and 3) serial LVOT VTI and cardiac index (CI) checks during support. We excluded patients with intraprocedural Impella insertion/removal. Results were plotted for a total of 80 LVOT VTI and corresponding CI values recorded spanning the implant-explant time. We plotted 3 correlation graphs for VTI to CI (Fig.1), iVTI (indexed LVOT VTI to patients' body surface area) to CI (Fig.2), and rVTI to rCI (relative LVOT VTI and CI to their initial values recorded following implant) (Fig.3). Results Results showed a positive regression of 0.6 for VTI/CI, 0.58 for iVTI/CI, and 0.77 for rVTI/rCI (p-value Conclusion As our data indicates, we provide a real-world standardized method that objectively focuses on routine evaluation of LVOT VTI as a surrogate of myocardial performance in cardiogenic shock requiring prolonged mechanical unloading. This method should therefore be taken one step further and considered for daily assessment of myocardial performance while weaning the support settings, as illustrated in our example (Fig.4), and be protocolized as a standard weaning parameter in shock centers.

Echocardiographic Characteristics Associated with Left Ventricular Recovery in Donor Hearts

Purpose There is a significant unmet patient need for heart transplantation that is in part driven by low donor heart utilization, with left ventricular (LV) systolic dysfunction the most common reason for non-allocation. Previous studies have shown a significant proportion of donors will have transient LV dysfunction, and these allocated hearts have no difference in post-transplant outcomes. We reviewed our OPO's protocol-driven management at a centralized diagnostic and recovery center to identify echocardiographic features associated with donor LV recovery. Methods A retrospective study of all potential donors managed at a single OPO between 2015-2017 with reduced initial LV ejection fraction (LVEF) ≤ 40%. Donors were divided into (1) LV recovery and (2) no recovery based on if subsequent echocardiogram revealed LVEF ≥ 50%. All donor echocardiograms were read by a single reader, including global longitudinal strain (GLS) analysis, to identify echocardiographic measures associated with recovery. Results 54 donors were included in this analysis, of which 29 (54%) had LV recovery, while 25 (54%) donors did not have LV recovery. Donors with LV recovery had a higher initial LVEF and trended towards having increased fractional shortening (FS) and LVOT VTI; they also had greater overall LVEF improvement. Donors with LV recovery had greater average LV GLS, right ventricle (RV) global and free wall longitudinal strain. However, when normalized for initial LVEF, strain was not independently associated with LV recovery. Conclusion In our experience managing potential donors at a centralized OPO, we found multiple echocardiographic measures were associated with LV recovery, including initial LVEF and both LV and RV GLS. However, strain did not seem to offer additional information, as it was not associated with recovery when normalized for initial LVEF. Additional work will further our ability to predict donors who will recover ventricular function and thus expand the cardiac donor pool.

Emergency department non-invasive cardiac output study (EDNICO): a feasibility and repeatability study

BackgroundThere is little published data investigating non-invasive cardiac output monitoring in the emergency department (ED). We assessed six non-invasive fluid responsiveness monitoring methods which measure cardiac output directly or indirectly for their feasibility and repeatability of measurements in the ED: (1) left ventricular outflow tract echocardiography derived velocity time integral, (2) common carotid artery blood flow, (3) suprasternal aortic Doppler, (4) bioreactance, (5) plethysmography with digital vascular unloading method, and (6) inferior vena cava collapsibility index.MethodsThis is a prospective observational study of non-invasive methods of assessing fluid responsiveness in the ED. Participants were non-ventilated ED adult patients requiring intravenous fluid resuscitation. Feasibility of each method was determined by the proportion of clinically interpretable measurements from the number of measurement attempts. Repeatability was determined by comparing the mean difference of two paired measurements in a fluid steady state (after participants received an intravenous fluid bolus).Results76 patients were recruited in the study. A total of 207 fluid responsiveness measurement sets were analysed. Feasibility rates were 97.6% for bioreactance, 91.3% for vascular unloading method with plethysmography, 87.4% for common carotid artery blood flow, 84.1% for inferior vena cava collapsibility index, 78.7% for LVOT VTI, and 76.8% for suprasternal aortic Doppler. The feasibility rates difference between bioreactance and all other methods was statistically significant.ConclusionOur study shows that non-invasive fluid responsiveness monitoring in the emergency department may be feasible with selected methods. Higher repeatability of measurements were observed in non-ultrasound methods. These findings have implications for further studies specifically assessing the accuracy of such non-invasive cardiac output methods and their effect on patient outcome in the ED in fluid depleted states such as sepsis.

Lack of correlation between left ventricular outflow tract velocity time integral and stroke volume index in mechanically ventilated patients

ObjectiveTo assess the correlation between left ventricular outflow tract velocity time integral (LVOT VTI) and stroke volume index (SVI) calculated by thermodilution methods in ventilated critically ill patients. DesignA prospective, descriptive, multicenter study was performed. SettingFive intensive care units from university hospitals. PatientsPatients older than 17 years needing mechanical ventilation and invasive hemodynamic monitoring were included. InterventionsLVOT VTI was measured by pulsatile Doppler echocardiography. Calculations of SVI were performed through a floating pulmonary artery catheter (PAC) or a Pulse index Contour Cardiac Output (PiCCO®) thermodilution methods. Main variablesThe relation between LVOT VTI and SVI was tested by linear regression analysis. ResultsOne hundred and fifty-six paired measurements were compared. Mean LVOT VTI was 20.83±4.86cm and mean SVI was 41.55±9.55mL/m2. Pearson correlation index for these variables was r=0.644, p<0.001; ICC was 0.52 (CI 95% 0.4–0.63). When maximum LVOT VTI was correlated with SVI, Pearson correlation index was r=0.62, p<0.001. Correlation worsened for extreme values, especially for those with higher LVOT VTI. ConclusionsLVOT VTI could be a complementary hemodynamic evaluation in selected patients, but does not eliminate the need for invasive monitoring at the present time. The weak correlation between LVOT VTI and invasive monitoring deserves additional assessment to identify the factors affecting this disagreement.