Left Ventricular Outflow Tract Velocity Research Articles

Echocardiographic findings and subsequent risk of native valve endocarditis

Aim: The association of echocardiographic findings and subsequent risk of left-sided native valve endocarditis (LS-NVE) is undefined. The aim of this study was to determine if transthoracic echocardiography (TTE) measurements are associated with the subsequent development of LS-NVE in patients without cardiac predisposing conditions. Methods: Institutional databases were evaluated for adults diagnosed with LS-NVE from 2008 to 2020. Patients with prosthetic valves, cardiovascular implantable electronic devices, intracardiac devices, injection drug use, and predisposing cardiac conditions were excluded. Only patients who had a TTE performed 6 months to 3 years before the development of LS-NVE were included as cases. Controls were patients within the same Mayo location with a TTE report and were matched in a 1:3 ratio according to age, gender, Charlson comorbidity index, and echocardiography date. Results: There were 148 cases and 431 matched controls. As compared to controls, infective endocarditis (IE) cases had a higher prevalence of diabetes mellitus (46.6% vs. 30.4%) and chronic kidney disease (46.6% vs. 28.1%) (P < 0.001). Left ventricular outflow tract velocity (P = 0.017), left ventricular ejection fraction (P = 0.018), and E:e’ ratio (P = 0.050) were associated with LS-NVE. Conclusions: Echocardiographic measurements were associated with subsequent LS-NVE development in this pilot study. A larger cohort of LS-NVE patients, however, is needed to validate these findings.

Association Between Left Ventricular Outflow Tract Velocity Time Integral, Ejection Fraction, and Mortality in an Undifferentiated Cohort of Hospitalised Patients

Association Between Left Ventricular Outflow Tract Velocity Time Integral, Ejection Fraction, and Mortality in an Undifferentiated Cohort of Hospitalised Patients

A combination of left ventricular outflow tract velocity time integral and lung ultrasound to predict mortality in ST elevation myocardial infarction.

Development of ventricular failure and pulmonary edema is associated with a worse prognosis in ST-elevation myocardial infarction (STEMI). We aimed to evaluate the prognostic ability of a novel classification combining lung ultrasound (LUS) and left ventricular outflow tract (LVOT) velocity time integral (VTI) in patients with STEMI. LUS and LVOT-VTI were performed within 24h of admission in STEMI patients. A LUS combined with LVOT-VTI (LUV) classification was developed based on LUS with < or ≥ 3 positive zone scans, combined with LVOT-VTI > or ≤ 14. Patients were classified as A (< 3zones/ > 14cm VTI), B (≥ 3zones/ > 14cm VTI), C (< 3zones/ ≤ 14cm VTI) and D (≥ 3zones/ ≤ 14cm VTI). Primary outcome was occurrence of in-hospital mortality. Development of cardiogenic shock (CS) within 24h was also assessed. A total of 308 patients were included. Overall in-hospital mortality was 8.8%, while mortality for LUV A, B, C, and D was 0%, 3%, 12%, and 45%, respectively. The area under the curve (AUC) for predicting in-hospital mortality was 0.915. Moreover, after exclusion of patients admitted in Killip IV, at each increasing degree of LUV, a higher proportion of patients developed CS within 24h: LUV A = 0.0%, LUV B 5%, LUV C = 12.5% and LUV D = 30.8% (p < 0.0001). The AUC for predicting CS was 0.908 (p < 0.001). In a cohort of STEMI patients, LUV provided to be an excellent method for prediction of in-hospital mortality and development of CS. LUV classification is a fast, non-invasive and very user-friendly ultrasonographic evaluation method to stratify the risk of mortality and CS.

Predicting and Measuring Fluid Responsiveness by Hemodynamic Indices versus Transthoracic Echocardiography in Clinically Shocked Patients

Abstract Background In the last decades dynamic measures had evolved as a better solution to predict fluid responsiveness in clinically shocked patients, out of multiple dynamic parameters we chose transthoracic echocardiographic based measurements of variations of aortic blood flow and inferior vena caval diameter. Aim of the Work to assess accuracy of transthoracic echo measured variation in aortic blood flow and inferior vena caval diameter with limited bolus crystalloid infusion in predicting fluid responsiveness in patients with clinical shock. Patients and Methods This study included 51 selected Patients with acute circulatory failure secondary to clinical shock admitted to ICU. All patients had undergone basic transthoracic echocardiographic (TTE) assessment of aortic blood flow (using left ventricular outflow tract velocity time integral as a surrogate) and inferior vena caval diameter changes with respiratory cycle, these measures were obtained at time of diagnosis of shock and repeated after infusion of 300 ml crystalloid fluid bolus (over fifteen minutes). Results Our results had revealed significant difference between responders and non-responders regarding aortic flow variation after fifteen minutes. Conclusion Based on the results obtained in this study, it was proved that transthoracic echocardiography can be used as an accurate method to predict fluid responsiveness in shocked patient with fluid challenge.

Centhaquine Increases Stroke Volume and Cardiac Output in Patients with Hypovolemic Shock.

Introduction: Centhaquine is a resuscitative agent that acts on α2B adrenergic receptors. Its effect on cardiac output in hypovolemic shock patients has not been reported. Methods: This pilot study was conducted in 12 hypovolemic shock patients treated with centhaquine who participated in an open-label phase IV study (NCT05956418). Echocardiography was utilized to measure stroke volume (SV), cardiac output (CO), left ventricular outflow tract velocity time integral (LVOT-VTI) and diameter (LVOTd), heart rate (HR), left ventricular ejection fraction (LVEF) and fractional shortening (LVFS), and inferior vena cava (IVC) diameter before (0 min) and 60, 120, and 300 min after centhaquine (0.01 mg/kg) iv infusion for 60 min. Results: SV was significantly increased after 60, 120, and 300 min. CO increased significantly after 120 and 300 min despite a decrease in HR. IVC diameter and LVOT-VTI at these time points significantly increased, indicating the increased venous return. LVEF and LVFS did not change, while the mean arterial pressure (MAP, mmHg) increased after 120 and 300 min. Positive correlations between IVC diameter and SV (R2 = 0.9556) and between IVC diameter and MAP (R2 = 0.8928) were observed, which indicated the effects of an increase in venous return on SV, CO, and MAP. Conclusions: Centhaquine-mediated increase in venous return is critical in enhancing SV, CO, and MAP in patients with hypovolemic shock; these changes could be pivotal for reducing shock-mediated circulatory failure, promoting tissue perfusion, and improving patient outcomes. Trial Registration: CTRI/2021/01/030263 and NCT05956418.

Low left ventricular outflow tract velocity time integral predicts normotensive shock in patients with acute pulmonary embolism

Abstract Funding Acknowledgements None. Introduction In patients with intermediate-risk acute pulmonary embolism (PE) outcomes vary widely, with mortality rates ranging from 3-15% and rates of normotensive shock up to 30%.1-3 Current risk models don't fully capture those at higher risk and identify patients who may benefit from advanced therapies. The left ventricular outflow tract (LVOT) velocity time integral (VTI), a surrogate marker of cardiac output, has been associated with increased mortality in acute PE.4 Our objective was to determine the association between LVOT VTI and its predictive value in identifying normotensive shock in this patient population. Methods Patients who underwent percutaneous mechanical thrombectomy (MT) between August 2020 and March 2023 at a large academic public hospital were considered for the study. Inclusion criteria comprised of normotensive patients (SBP ≥ 90 mmHg) with invasive measures of cardiac index (CI). VTI was obtained by pulsed wave doppler at the LVOT in either the apical 3 or apical 5 chamber view. The primary outcome was the association between LVOT VTI and normotensive shock and a cut off of 15 cm was used to examine this association based on prior studies.4 Results A total of 49 patients with intermediate-risk PE underwent MT, 16 patients had incomplete data, resulting in a final cohort of 33 patients (mean age: 57 ± 13yrs; 38% female). Patients with LVOT VTI of &amp;lt;15 cm were younger (53 vs 62 years p=0.02), had lower systolic blood pressure at presentation (122 vs 134 mmHg, p=0.047), higher heart rate (112.6 vs 96.2 beats/min, p=0.008), a higher composite shock score (CPES) (5 vs 3, p=0.012), lower cardiac index (1.9 vs 3.1 L/min/m2, p&amp;lt;0.001), a higher PASP (61.4 vs 48.9 mmHg, p=0.018), and higher rates of elevated lactate (90% vs 42%, p=0.027). LVOT VTI threshold of &amp;lt;15cm effectively identified patients with normotensive shock (90% vs 8% p&amp;lt;0.001). There was no statistically significant difference in the rates of saddle emboli, left ventricular ejection fraction, sPESI and BOVA scores in patients with VTI above or below 15cm. In patients with normotensive shock, 19/20 (95%) had LVOT VTI ≤ 15cm with a median of 13 cm (IQR 12, 14) (Figure). In patients without normotensive shock, 11/13 (84%) had LVOT VTI &amp;gt;15 with a median of 18 (IQR 17, 21). The area under the curve for LVOT VTI ≤ 15 cm in predicting normotensive shock was 0.89. The sensitivity and specificity of LVOT VTI ≤ 15 cm in predicting normotensive shock was 91.6% and 90.4% respectively. Conclusion Our study suggests that LVOT VTI is a reliable surrogate for cardiac output in patients with acute PE and can effectively identify those in the intermediate-risk group who are at risk for normotensive shock. A LVOT VTI &amp;lt;15cm may identify intermediate-risk patients at higher risk for hemodynamic decompensation and further studies are needed to evaluate whether these patients would benefit from upfront catheter-based therapies.

Risk assessment by acute bedside echocardiography prior to acute coronary angiography in patients with ST-elevation myocardial infarction: a feasibility study

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Novo Nordisk Foundation. Background Early risk assessment by hemodynamic measurements in patients with ST-elevation myocardial infarction (STEMI) could be useful for early detection of patients at risk of developing hemodynamic instability after primary percutaneous coronary intervention (pPCI). Anterior STEMI patients have larger infarct size and may be of particular interest. Transthoracic echocardiography (TTE) is a quick, non-invasive, and available tool, however, evidence regarding the use of acute TTE prior to acute coronary angiography (CAG) is limited. Purpose To assess the feasibility of acute bedside hemodynamic assessment in the cath. lab. by TTE in addition to clinical examination, and blood samples in STEMI patients without CS at arrival in the cath. lab. Methods STEMI patients without CS at hospital arrival and treated with pPCI were included in the study during a five week period. Clinical examination (Killip class), blood sampling (lactate, troponin T (TNT), proB-type natriuretic peptide (proBNP), and focused bedside 2D TTE with Doppler were performed prior to the acute CAG. The TTE protocol was focused (approx. 5 minutes) on hemodynamic measurements, infarction related complications, and differential diagnoses e.g. aortic dissection. The TTE was performed during preparation for the acute CAG. Patients were stratified in anterior- vs. non-anterior STEMI based on the culprit artery and prehospital ECG. Feasibility was estimated by all of the following echocardiographic parameters; left ventricular ejection fraction (LVEF), left ventricular outflow tract (LVOT) velocity time integral (VTI), and right ventricular function (tricuspid annular plane systolic excursion (TAPSE)). Results A total of 60 STEMI patients (aged mean 63 years, 18% female) were included, and 47% had an anterior STEMI. No differences in baseline characteristics between the two groups were found including comorbidities, clinical parameters, and time from cath. lab. arrival to first wire over the culprit lesion (median (IQR) 28 (23; 38) vs 32 (24; 40) minutes). Admission biomarkers of blood glucose, lactate, and proBNP plasma concentrations were similar between the two groups. Whereas admission TNT were higher for patients with anterior STEMI (median (IQR) 110 (37; 449) vs. 37 (20; 94) ng/L, p=0.01). The feasibility of TTE-study protocol was 93%. Patients with anterior STEMI had lower LVEF (mean: 36±11 vs. 48±9%, p=0.0003; missing: n=0), and a trend to lower LVOT VTI (19 (6.4) vs. 22 (5.0) cm, p=0.06; missing: n=4). No difference in parameters of diastolic function or TAPSE (missing: n=0) were found. None of the included patients had echocardiographic visible complications related to the infarction. Conclusion Acute TTE is to a high degree feasible and does not delay time to acute revascularization in STEMI patients. Patients with anterior STEMI have significantly higher admission TNT levels, lower LVEF, and a trend to lower LVOT VTI compared with non-anterior STEMI patients.

Association between speckle tracking echocardiography and pressure-volume loops during cardiogenic shock development

BackgroundThe relationship between speckle tracking assessed global longitudinal strain (GLS) and Doppler-based echocardiography with basic physiological markers of cardiac function derived from pressure-volume loops is poorly elucidated.ObjectiveWe aimed to describe...

Low left ventricular outflow tract velocity time integral predicts normotensive shock in patients with acute pulmonary embolism

In this study, we found that a low LVOT VTI (<15 cm), a simple bedside point-of-care measurement, predicts normotensive shock in patients with acute intermediate-risk PE.

Septic cardiomyopathy phenotype in the critically ill may depend on antimicrobial resistance

BackgroundSepsis is a life-threatening organ dysfunction, and septic cardiomyopathy (SCM) may complicate the course of the disease. Infection with multidrug-resistant (MDR) pathogens has been linked with worse outcomes. This study aims to evaluate SCM in patients with infections caused by different antimicrobial-resistant phenotypes. MethodThis retrospective study included patients with sepsis/septic shock, hospitalized, and intubated in the intensive care unit of the University Hospital of Larissa between January 2022 and September 2023 with echocardiographic data during the first two days after infection onset. The patients were divided into two groups: non-MDR-SCM group and MDR-SCM group. The cardiac function was compared between the two groups. ResultA total of 62 patients were included in the study. Forty-four patients comprised the MDR-SCM and 18 the non-MDR-SCM group. Twenty-six patients (41.9%) presented with left ventricular (LV) systolic dysfunction, and ≤35% right ventricular fractional area change (RVFAC) was present in 56.4%. LV systolic function was more severely impaired in the non-MDR-SCM group (left ventricular ejection fraction, 35.8% ±4.9% vs. 45.6%±2.4%, P=0.049; LV outflow tract velocity time integral, [10.1±1.4] cm vs. [15.3±0.74] cm, P=0.001; LV-Strain, –9.02%±0.9% vs. –14.02%±0.7%, P=0.001). The MDR-SCM group presented with more severe right ventricular (RV) dilatation (right ventricular end-diastolic area/left ventricular end-diastolic area, 0.81±0.03 vs. 0.7±0.05, P=0.042) and worse RV systolic function (RVFAC, 32.3%±1.9% vs. 39.6%±2.7%, P=0.035; tricuspid annular plane systolic excursion, [15.9±0.9] mm vs. [18.1±0.9] mm, P=0.165; systolic tissue Doppler velocity measured at the lateral tricuspid annulus, [9.9±0.5] cm/s vs. [13.1±0.8] cm/s, P=0.002; RV-strain, –11.1%±0.7% vs. –15.1%±0.9%, P=0.002). ConclusionSCM related to MDR infection presents with RV systolic dysfunction predominance, while non-MDR-SCM is mainly depicted with LV systolic dysfunction impairment.

The Utility of Echocardiography in Estimating Fluid Responsiveness.

Assessing the volume status in critically ill patients is the key to maintain the stability of the hemodynamics; however, it can be challenging to view the complexity of cases and the diversity of shock etiology. Multiple noninvasive means have been used to study the effectiveness of volume resuscitation, but none of them have been used as gold standard. We aim to illustrate the most used techniques: left ventricular outflow tract velocity time integral versus inferior vena cava compressibility index, and highlight their limitations and strengths. These tools are both operator-dependent and might be affected by several factors including ventilator settings.

A Curious Case of Left Ventricular Outflow Tract Velocity Time Integral Alternans With an Intra-Aortic Balloon Pump: Physiology in Action

A Curious Case of Left Ventricular Outflow Tract Velocity Time Integral Alternans With an Intra-Aortic Balloon Pump: Physiology in Action

Diagnostic accuracy of left ventricular outflow tract velocity time integral versus inferior vena cava collapsibility index in predicting post-induction hypotension during general anesthesia: an observational study.

Point of care ultrasound (POCUS) is being explored for dynamic measurements like inferior vena cava collapsibility index (IVC-CI) and left ventricular outflow tract velocity time integral (LVOT-VTI) to guide anesthesiologists in predicting fluid responsiveness in the preoperative period and in treating post-induction hypotension (PIH) with varying accuracy. In this prospective, observational study on included 100 adult patients undergoing elective surgery under general anesthesia, the LVOT-VTI and IVC-CI measurements were performed in the preoperative room 15 minutes prior to surgery, and PIH was measured for 20 minutes in the post-induction period. The incidence of PIH was 24%. The area under the curve, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the two techniques at 95% confidence interval was 0.613, 30.4%, 93.3%, 58.3%, 81.4%, 73.6% for IVC-CI and 0.853, 83.3%, 80.3%, 57.1%, 93.8%, 77.4% for LVOT-VTI, respectively. In multivariate analysis, the cutoff value for IVC-CI was >51.5 and for LVOT-VTI it was ≤17.45 for predicting PIH with odd ratio [OR] of 8.491 (P=0.025) for IVCCI and OR of 17.427 (P<0.001) for LVOT. LVOT-VTI assessment was possible in all the patients, while 10% of patients were having poor window for IVC measurements. We recommend the use of POCUS using LVOT-VTI or IVC-CI to predict PIH, to decrease the morbidity of patients undergoing surgery. Out of these, we recommend LVOT-VTI measurements as it has showed a better diagnostic accuracy (77.4%) with no failure rate.

The left ventricular outflow tract and carotid artery velocity time integrals

The left ventricular outflow tract velocity time integral (LVOT VTI) is commonly used in the intensive care unit as a measure of stroke volume (SV) and how the SV changes in response to an intervention; therefore, the LVOT VTI is used to guide intravenous fluid management. Various peripheral Doppler surrogates are proposed to infer the LVOT VTI (e.g., measures from the common carotid artery). A recently-described, novel method of insonation has an excellent ability to detect change in the LVOT VTI. This approach raises important facets of Doppler flow and insonation error, as well as the general principles at play when using a peripheral artery to infer changes from the left ventricle. Relating the VTI of a peripheral artery to the LVOT VTI was recently described mathematically and may help clinicians think about the Doppler relationship between central and peripheral flow.

Association between speckle tracking echocardiography and pressure-volume loop derived parameters at increasing levels of myocardial damage in a porcine model of acute cardiogenic shock

Abstract Background Echocardiography is a diagnostic cornerstone in acute cardiovascular care. However, the relationship between speckle tracking assessed global longitudinal strain (LS) and Doppler-based echocardiography with basic physiological markers of cardiac function derived from pressure-volume loops remains poorly elucidated, especially with increasing levels of myocardial damage. Objectives We aimed to describe the association between LS and Doppler-based echocardiography and direct measurements of central hemodynamic parameters from conductance catheter-based pressure-volume loops in an animal model with increasing left ventricular (LV) dysfunction. Methods Twelve Danish landrace pigs weighing 75-80 kg were used. All instrumentations were performed percutaneously, including placement of a conductance catheter in the LV. Progressive LV dysfunction was induced by stepwise embolization trough the left main coronary artery every three minutes until a 50% reduction in cardiac output or mixed venous saturation, compared to baseline, or a mixed venous saturation &amp;lt;30%. Echocardiography was performed through a subxiphoid midline incision, and was done at baseline and 90 seconds after each injection. Results With progressive LV dysfunction, mean cardiac output decreased from 5.6 l/min (SD: 0.9) to 2.1 l/min (SD: 0.9) and mean mixed venous saturation deteriorated from 61.1%(SD: 7.9) to 35.3% (SD: 6.1). Mean LS and LV outflow tract velocity time integral (LVOT VTI) declined from -13.8% (SD 3.0) to -6.1% (SD: 2.0) and 16.9 cm (SD: 2.6) to 7.8 cm (SD: 1.8), respectively (Figure 1). LS and LVOT VTI showed the strongest correlation to stroke work in unadjusted univariate regression (r2=0.53 and r2=0.49, respectively. p&amp;lt;0.01 for both). LS correlated significantly, but modest, with stroke volume (r2=0.46, p&amp;lt;0.01), end-systolic elastance (r2=0.32, p&amp;lt;0.01), systolic blood pressure (r2=0.37, p&amp;lt;0.01), ventriculo-arterial coupling(r2=0.34, p&amp;lt;0.01), and arterial elastance (r2=0.23, p&amp;lt;0.01) (Figure 2). In a multivariate regression analysis, LS showed significant correlation with stroke work, systolic blood pressure, and end-diastolic wall stress (r2=0.60, p&amp;lt;0.01). Conclusion In an animal model of acute progressive LV dysfunction, echocardiographic and conductance catheter-based measurements changed significantly. LS and LVOT VTI displayed the earliest and the largest alterations with increased myocardial damage and LS showed moderate correlations with contractility, arterial elastance and ventriculo-arterial coupling. This indicates that LS is a marker of overall ventricular performance.Echocardiographic changes from baselineScatter plot of LS and hemodynamics

Abstract 12875: Echocardiographic Findings Associated With Subsequent Risk of Native Valve Endocarditis

Introduction: The association of echocardiographic measurements and subsequent risk of left-sided native valve endocarditis (LS-NVE) is undefined. Aim: To determine if transthoracic echocardiographic (TTE) measurements are associated with the subsequent development of LS-NVE in patients without recognized cardiac predisposing conditions. Methods: Institutional databases were evaluated for adults diagnosed with LS-NVE from 2008 to 2020. Patients with prosthetic valves, cardiovascular implantable electronic devices, intracardiac devices, injection drug use, and recognized predisposing cardiac conditions were excluded. Patients with a TTE performed 6 months to 3 years before developing LS-NVE were included as cases. Controls were patients within the same Mayo Clinic location with a TTE report and were matched in a 1:3 ratio according to age, gender, Charlson Comorbidity Index (CCI), and echocardiography date. Multivariate logistic-regression analyses adjusting significant variables between cohort's were performed. A p-value &lt;0.05 was considered significant. Results: There were 148 cases and 431 matched controls. The median age was 63.8 (IQR: 53.6 - 74.6) years, and 329 (56.8%) patients were males. LS-NVE cases had a higher prevalence of diabetes mellitus (46.6% vs. 30.4%) and chronic kidney disease (46.6% vs. 28.1%) when compared with controls (p&lt;0.001 both). The median CCI score was 3 (IQR: 0-6) for cases and 2 (IQR: 0-6) for controls. After performing adjusted analyses, left ventricular outflow tract velocity (p=0.017), left ventricular ejection fraction (p=0.018), and E: e’ ratio (p=0.050) were associated with the development of LS-NVE ( Figure 1) . Conclusions: Echocardiographic measurements were associated with subsequent LS-NVE development in this preliminary investigation. A larger cohort of LS-NVE patients is needed to validate these findings.

Abstract 13250: Establishing Partition Values and Clinical Phenotype for Heart Failure Patients With Abnormal Left Atrial Function Index: A Cross-Sectional Analytical Study

Introduction: Left atrial function index (LAFI) has recently been validated for global estimation of left atrial (LA) function. LA dysfunction is critical to developing overt heart failure (HF), and getting the best tool for assessing its function is critical to HF prevention. This study attempts to establish cut-off values for LAFI among HF patients and identify which HF phenotype is associated with abnormal LAFI. Hypothesis: Is there any association between abnormal LAFI and changes in LV function? Methods: This cross-sectional study was conducted at the Delta State University Teaching Hospital, Nigeria. We recruited 80 hypertensive HF patients and 40 healthy normotensive controls. LAFI = (LAEF x LVOT-VTI)/LAESVI. (LAEF = left atrial emptying fraction; LAESVI = left atrial end-systolic volume index; LVOT-VTI = left ventricular outflow tract velocity time integral). Relationships between variables were determined using an independent student’s t-test, and a P-value of &lt;0.05 was significant. Results: In the control arm, the LAFI reference range was estimated to be 24.07-76.24. Abnormal LAFI was defined as LAFI &lt; 24 and 77.5% of the individuals with HF were found to have abnormal LAFI. There was no difference in age (61.83±7.48 vs. 63.22±6.75, p=0.46), BMI (28.27±4.47 vs. 29.52±5.91, p=0.33) and systolic BP (127.34±19.28 vs. 120.94±19.94, p=0.22) of hypertensive HF patients with LAFI &lt;24 and LAFI ≥24. Those with abnormal LAFI had lower EF (45.04±11.06 vs. 63.73±14.73, p&lt;0.0001), FS (25.75±8.26 vs 32.49±8.64, p=0.003) and SV (57.16±13.30 vs. 64.99±16.94, p=0.02). However, E/E’ (15.62±5.61 vs. 9.2±3.22, p&lt;0.0001) and LAVI (37.22±5.80 vs. 16.48±5.65, p&lt;0.0001) were higher among patients with lower LAFI. Contrarily, E/A (1.87±0.97 vs. 1.87±0.83, p=0.98) and TAPSE (17.87±3.67 vs. 19.54±2.47, p=0.06) did not show any difference among the groups. Conclusions: This study shows that abnormal LAFI was associated with impaired LV function and it is crucial to deploy this non-invasive modality of cardiac assessment in hypertensive patients. Early identification of abnormal left atrial mechanics is pertinent to preventing overt HF, especially in parts of the world where access to advanced cardiovascular care is limited.

Abstract 13550: Prognostic Value of the Global Left Ventricular Contractility Index in Patients With Severe Mitral Regurgitation and Preserved Left Ventricular Ejection Fraction

Introduction: Global left ventricular (LV) contractility index, dσ*/dt max , defined as the maximal rate of change of pressure-normalized LV wall stress, is given by the formula 3(dV/dt) max /2V m where dV/dt max is the product of left ventricular outflow tract (LVOT) velocity and area; and V m , left ventricular mass index (LVMI). In published reports, prediction of clinical outcomes in aortic stenosis were observed. It is unknown if dσ*/dt max would predict clinical outcomes in patients with severe mitral regurgitation (MR). Aim: We studied the association of dσ*/dt max with clinical outcomes in severe MR with preserved LV ejection fraction (EF). Methods: Consecutive patients with severe MR and LVEF ≥50% diagnosed on index echocardiogram at a single centre were retrospectively analyzed. Patients with other valvular lesions of moderate severity or more, or valvular interventions, were excluded. Clinical outcomes were ascertained by review of medical records. The primary outcome was a composite of heart failure hospitalizations and all-cause mortality. Results: 176 patients were included in the analysis. Table 1 depicts the characteristics of the study population. Patients with composite outcomes were older, more likely to be female, had higher LVMI, lower regurgitation volume and dσ*/dt max (2.2 +/- 0.7 vs 2.7 +/- 0.9, p = 0.02). On multivariable Cox regression (Table 2), only age and dσ*/dt max (adjusted HR 0.42, 95% CI: 0.220 - 0.806, p = 0.01) remained independently associated with occurrence of the primary outcome. Conclusions: In patients with isolated severe mitral regurgitation and preserved LVEF, low dσ*/dt max was an independent predictor of adverse clinical outcomes.

Association of Shock Index with Echocardiographic Parameters in Cardiac Intensive Care Unit

BackgroundA high shock index (SI), the ratio of heart rate (HR) to systolic blood pressure (SBP), has been associated with unfavorable outcomes. We sought to determine the hemodynamic underpinnings of an elevated SI using 2-D and doppler Transthoracic Echocardiography (TTE) in unselected cardiac intensive care unit (CICU) patients. MethodsWe included Mayo Clinic CICU admissions from 2007 to 2018 who were in sinus rhythm at the time of TTE. The SI was calculated using HR and SBP at the time of TTE. Patients were grouped according to SI: <0.7, 4012 (64%); 0.7–0.99, 1764 (28%); and ≥ 1.0, 513 (8%). Pearson's correlation coefficient was used to assess associations between continuous variables. ResultsWe included 6289 unique CICU patients, 58% of whom had acute coronary syndrome. The median age was 67.9 years old and 37.8% were females. The mean SI was 0.67 BPM/mmHg. As the SI increased, markers of left ventricular (LV) systolic function and forward flow decreased, including left ventricular ejection fraction (LVEF), fractional shortening, left ventricular outflow tract (LVOT) velocity time integral (VTI), stroke volume, LV stroke work index, and cardiac power output. Biventricular filling pressures increased, and markers of right ventricular function worsened with rising SI. Most TTE measurements reflecting LV function and forward flow were inversely correlated with SI, including LV stroke work index (r = −0.59) and LVOT VTI (r = −0.41), as were both systemic vascular resistance index (r = −0.43) and LVEF (r = −0.23). ConclusionCICU patients with elevated SI have worse biventricular function and systemic hemodynamics, particularly decreased stroke volume and related calculated TTE parameters. The SI is an easily available marker that can be used to identify CICU patients with unfavorable hemodynamics who may require further assessment.

Reliability of point-of-care ultrasound to evaluate fluid tolerance performed by critical care residents

BackgroundPatients with hypotension usually receive intravenous fluids, but only 50% will respond to fluid administration. We aimed to assess the intra and interobserver agreement to evaluate fluid tolerance through diverse ultrasonographic methods.MethodsWe prospectively included critically ill patients on mechanical ventilation. One trained intensivist and two intensive care residents obtained the left ventricular outflow tract velocity–time integral (VTI) variability, inferior vena cava (IVC) distensibility index, internal jugular vein (IJV) distensibility index, and each component of the venous excess ultrasound (VExUS) system. We obtained the intraclass correlation coefficient (ICC) and Gwet’s first-order agreement coefficient (AC1), as appropriate.ResultsWe included 32 patients. In-training observers were unable to assess the VTI-variability in two patients. The interobserver agreement was moderate to evaluate the IJV-distensibility index (AC1 0.54, CI 95% 0.29–0.80), fair to evaluate VTI-variability (AC1 0.39, CI 95% 0.12–0.66), and absent to evaluate the IVC-distensibility index (AC1 0.19, CI 95% − 0.07 to 0.44). To classify patients according to their VExUS grade, the intraobserver agreement was good, and the interobserver agreement was moderate (AC1 0.52, CI 95% 0.34–0.69).ConclusionsPoint-of-care ultrasound is frequently used to support decision-making in fluid management. However, we observed that the VTI variability and IVC-distensibility index might require further training of the ultrasound operators to be clinically useful. Our findings suggest that the IJV-distensibility index and the VExUS system have acceptable reproducibility among in-training observers.