Left Ventricular Outflow Tract Velocity Research Articles

Validation of Epworth Richmond's Echocardiography Education Focused Year.

OBJECTIVES: College of Intensive Care Medicine mandatory training in echocardiography requires a minimum 30 echocardiograms. Trainee echocardiography accuracy following mandatory training is unknown. Our objective was to determine the reliability of ICU trainee echocardiography after our yearlong College of Intensive Care Medicine accredited course. DESIGN: Single-center, prospective observational study. Trainee echocardiograms were compared to independent, blindedexpert echocardiograms, with a target of 37 matched scans per trainee. SUBJECTS: Trainees were eligible to participate on completion of our in-house, mandatory echocardiography training. SETTING: Epworth Richmond is in an Australian, private academic hospital with a critical care echocardiography teaching program. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Reliability was assessed on nine measurements. The primary outcome was agreement on left ventricular function; secondary outcomes included qualitative and quantitative assessments. Agreement was assessed using Cohen's kappa, Fleiss-Cohen weighted kappa, Lin's concordance correlation coefficient, or calculation of sensitivity and specificity as appropriate. Seven trainees performed a total of 270 matched scans. There was excellent agreement between experts and trainees for left ventricular function (Kappa, 0.86; 95% CI, 0.81-0.91). Secondary outcome measures (95% CI) were ventricular size ratio Kappa 0.76 (0.58-0.94), sensitivity 92.3% (64.0-99.8%), specificity 97.2% (94.9-99.1%), pericardial effusion Kappa 0.37 (0.13-0.60), sensitivity 33.3% (13.3-59.0%), specificity 97.6% (94.8-99.1%). Concordance coefficients (95% CI) for the remaining outcomes were left ventricular outflow tract velocity time integral 0.79 (0.74-0.84), left ventricular internal diameter in diastole 0.82 (0.78-0.86), left ventricular outflow tract diameter 0.61 (0.53-0.69), tricuspid annular plane systolic excursion 0.71 (0.64-0.78), tricuspid regurgitation maximum velocity 0.55 (0.44-0.65), and inferior vena cava diameter 0.60 (0.49-0.72). CONCLUSIONS: ICU trainees showed very high overall agreement with experts on left ventricular function and substantial agreement for most secondary outcomes. This is the first study to assess echocardiography accuracy in Australian ICU trainees.

Low left ventricular outflow tract velocity time integral is associated with poor outcomes in acute pulmonary embolism.

The left ventricular outflow tract (LVOT) velocity time integral (VTI) is an easily measured echocardiographic stroke volume index analog. Low values predict adverse outcomes in left ventricular failure. We postulate the left ventricular VTI may be a signal of right ventricular dysfunction in acute pulmonary embolism, and therefore a predictor of poor outcomes. We retrospectively reviewed echocardiograms on all Pulmonary Embolism Response Team activations at our institution at the time of pulmonary embolism diagnosis. Low LVOT VTI was defined as ⩽ 15 cm. We examined two composite outcomes: (1) in-hospital death or cardiac arrest; and (2) shock or need for primary reperfusion therapies. Sixty-one of 188 patients (32%) had a LVOT VTI of ⩽ 15 cm. Low VTI was associated with in-hospital death or cardiac arrest (odds ratio (OR) 6, 95% CI 2, 17.9; p = 0.0014) and shock or need for reperfusion (OR 23.3, 95% CI 6.6, 82.1; p < 0.0001). In a multivariable model, LVOT VTI ⩽ 15 remained significant for death or cardiac arrest (OR 3.48, 95% CI 1.02, 11.9; p = 0.047) and for shock or need for reperfusion (OR 8.12, 95% CI 1.62, 40.66; p = 0.011). Among intermediate-high-risk patients, low VTI was the only variable associated with the composite outcome of death, cardiac arrest, shock, or need for reperfusion (OR 14, 95% CI 1.7, 118.4; p = 0.015). LVOT VTI is associated with adverse short-term outcomes in acute pulmonary embolism. The VTI may help risk stratify patients with intermediate-high-risk pulmonary embolism.

Outcomes After Left Ventricular Outflow Tract Reconstruction With a Tube Graft for Annular Erosion

Aortic annular erosion is a serious complication of aortic valve endocarditis or previous aortic valve replacement. This study examined the outcomes of a technique for left ventricular outflow tract reconstruction using a polyester tube graft, followed by translocation of the aortic valve and coronary arteries. A total of 23 patients with extensive annular erosion resulting from endocarditis or previous aortic valve replacement with or without pseudoaneurysm formation, or occurring after excision of the native valve, underwent suture of a polyester tube graft in the left ventricular outflow tract below the annulus, replacement of the aortic valve and proximal ascending aorta with a composite graft, and reimplantation of the coronary arteries with the use of interposition polyester grafts. The mean age of the patients was 50 years, and 57% were men. There were no hospital deaths. The mean duration of follow-up was 6.5 years and extended to 16 years. Actuarial survival at 1, 5, and 10 years was 86.7%, 82.2%, and 62.6%, respectively. Two patients required reoperation for a graft-graft pseudoaneurysm and for degeneration of a porcine bioprosthesis. Echocardiograms obtained at a mean of 75 months postoperatively in 15 of the 23 patients demonstrated normal left ventricular outflow tract dimensions and velocities and a mean effective valve orifice area of 1.07 cm2/m2. All coronary artery grafts were patent on angiography a mean of 40 months postoperatively in 13 patients. Extended experience with this technique confirms its safety and effectiveness for patients withextensive destruction of the aortic annulus. It represents a suitable alternative to other currently used techniques.

Assessment of myocardial function in obstructive hypertrophic cardiomyopathy cats with and without response to medical treatment by carvedilol

BackgroundInconsistency of treatment response in cats with obstructive hypertrophic cardiomyopathy is well recognized. We hypothesized that the difference in response to beta-blockers may be caused by myocardial functional abnormalities. This study was designed to compare myocardial function in cats with obstructive hypertrophic cardiomyopathy with and without response to beta-blockers. Twenty-one, client-owned, hypertrophic cardiomyopathy cats treated with carvedilol were analyzed. After carvedilol treatment, cats with decreased left ventricular outflow tract velocity were categorized as responders (n = 10); those exhibiting no response (no decrease in the left ventricular outflow tract velocity) were categorized as non-responders (n = 11). The cats were examined using layer-specific assessment of the myocardial function (whole, endocardial, and epicardial layers) longitudinally and circumferentially by two-dimensional speckle-tracking echocardiography, before and after carvedilol treatment.ResultsThe non-responder cats had a significantly higher age, end-diastolic left ventricular posterior-wall thickness, peak velocity of left ventricular outflow tract, and dose of carvedilol than the responders (p = 0.04, p < 0.01, p < 0.01, and p < 0.01, respectively). The circumferential strain in the epicardial layer was lower and circumferential endocardial to epicardial strain ratio was higher in non-responders than responders (p < 0.001 and p = 0.006). According to the multivariate analysis, circumferential strain in the epicardial layer was the only independent correlate of treatment response with carvedilol.ConclusionsMyocardial function, assessed by two-dimensional speckle-tracking echocardiography, differed in cats with hypertrophic cardiomyopathy with and without response to beta-blockers. The determination of layer-specific myocardial function may facilitate detailed pathophysiologic assessment and treatment response in cats with hypertrophic cardiomyopathy.

P2634Prognostic value of admission left ventricular outflow tract velocity time integral in hospitalized heart failure patients with preserved ejection fraction: a report from the JASPER registry

Abstract Background There are little effective treatment strategies for heart failure with preserved ejection fraction (HFpEF) to achieve a reduction of morbidity and mortality. Thus, accurate prognostication of patients with HFpEF could help improve their outcomes by identifying high-risk patients who might potentially benefit from intensive inpatient and outpatient monitoring and early referral for advanced HFpEF therapy. The left ventricular outflow tract velocity time integral (LVOT-VTI) is a representative non-invasive parameter for evaluating stroke volume, which can be a determinant of adverse outcomes in hospitalized patients with heart failure. However, the prognostic implication of admission LVOT-VTI for hospitalized HFpEF patients is undetermined. Purpose The aim of the present study was to investigate whether admission LVOT-VTI could predict poor clinical outcomes in hospitalized patients with HFpEF. Methods We examined consecutive 535 hospitalized HFpEF patients (left ventricular ejection fraction ≥50%) due to acute decompensated heart failure from the JASPER (JApanese heart failure Syndrome with Preserved Ejection fRaction) multicenter registry, obtained between November 2012 and March 2015. Patients without accessible LVOT-VTI data on admission were excluded. Finally, 214 patients were examined. The primary outcome of interest was composite of all-cause death and rehospitalization due to heart failure. Results Mean age was 78±11 years, 100 were male, and median plasma brain-type natriuretic peptide level was 400 (interquartile range [IQR] 223–711) pg/ml. During a median follow-up period of 688 (IQR 162–810) days, adverse events occurred in 83 patients (39%), including 47 (22%) all-cause death, 51 (24%) rehospitalization due to heart failure. The c-index of LVOT-VTI for predicting the composite of adverse events was 0.59 (95% CI 0.51 to 0.67), and the optimal cut-off value of LVOT-VTI was 15.8 cm. Low LVOT-VTI (≤15.8 cm) was significantly associated with higher adverse events compared to high LVOT-VTI (&gt;15.8 cm) (Figure). Multivariable Cox regression analysis revealed that lower LVOT-VTI was an independent determinant of adverse events (HR 0.94, 95% CI 0.91 to 0.98, P=0.005) even after adjustment for pre-specified confounders including age, sex, systolic blood pressure, serum sodium, albumin, plasma brain-type natriuretic peptide and renal function. Figure 1 Conclusions Lower admission LVOT-VTI was an independent determinant of worse clinical outcomes in hospitalized HFpEF patients, indicating that LVOT-VTI on admission could be a useful marker for risk stratification in these patients.

Quantitative Transthoracic Echocardiography of the Response to Dobutamine in Cardiac Surgery Patients With Low Cardiac Output Syndrome

To quantify the acute effects of dobutamine in postoperative low cardiac output syndrome (LCOS) using transthoracic echocardiographic, hemodynamic, and blood biomarker monitoring and to assess its association with clinical outcomes. Observational prospective study. Single university hospital. Patients undergoing elective cardiac surgery. None. Echocardiographic parameters, hemodynamic data, and plasma biomarkers were obtained before and early after inotrope initiation. The diagnostic value of transthoracic echocardiographic parameters and their association with clinical outcome were evaluated. Thirty-eight LCOS patients and 12 control patients were included. The left ventricular outflow tract velocity time integral was significantly lower in LCOS patients (11.75 v 19.08 cm; p < 0.001) and showed a marked improvement after dobutamine administration (∼37% increase). Dobutamine improved left and right ventricular function, increased mean arterial pressure and urine output, and lowered lactate levels. The duration of dobutamine support, but not in-hospital mortality, was associated with echocardiographic estimates of cardiac performance early after dobutamine initiation. Early transthoracic echocardiographic assessment and the acute response to inotropic therapy may provide rapid and highly valuable information in the diagnostic workup and risk evaluation of patients with suspected LCOS after cardiac surgery.

Relation of Systolic Blood Pressure on the Following Day with Post-Discharge Mortality in Hospitalized Heart Failure Patients with Preserved Ejection Fraction.

The clinical scenario, which is based on systolic blood pressure (SBP) upon admission, is useful for classifying and determining initial treatment for acute heart failure (HF). However, the prognostic significance of SBP following the initial treatment is unclear.The Japanese Heart Failure Syndrome with Preserved Ejection Fraction (JASPER) registry is a nationwide, observational, and prospective registration of consecutive Japanese patients hospitalized with HF with preserved ejection fraction (HFpEF) and left ventricular ejection fraction ≥ 50%. We divided 525 patients into three groups based on their SBP on the day following hospitalization: high (SBP > 140 mmHg, n = 72, 13.7%); normal (100 ≤ SBP ≤ 140 mmHg, n = 379, 72.2%); and low (SBP < 100 mmHg, n = 74, 14.1%) groups. This analysis had two primary endpoints: (1) all-cause death and (2) all-cause death or rehospitalization for HF. In the Kaplan-Meier analysis, both of the endpoints were the highest in the low group (Log-Rank < 0.05, respectively). Compared to the normal and high groups, the low group demonstrated a higher prevalence of atrial fibrillation (67.1%, 63.9%, and 47.8%, P = 0.026) and the lowest left ventricular outflow tract velocity time integral determined by echocardiography (16.4 cm, 19.4 cm, and 23.3 cm, P = 0.001). In the multivariable Cox proportional hazard analysis, low SBP on the day following hospitalization was an independent predictor of all-cause death (hazard ratio 1.868, 95% confidence interval 1.024-3.407, P = 0.042) and the composite endpoint (hazard ratio 1.660, 95% confidence interval 1.103-2.500, P = 0.015).Classification based on SBP on the day following initial treatment predicts post-discharge prognosis in hospitalized patients with HFpEF.

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.

Cardiac Effects of a Single Dose of Pimobendan in Cats With Hypertrophic Cardiomyopathy; A Randomized, Placebo-Controlled, Crossover Study.

Background: Pimobendan has been shown to impart a significant survival benefit in cardiomyopathic cats who receive it as part of heart failure therapy. However, use of pimobendan remains controversial in cats with hypertrophic cardiomyopathy (HCM) due to lack of pharmacodynamic data for pimobendan in cats with HCM and due to theoretical concerns for exacerbating left ventricular outflow tract obstructions.Hypothesis/Objectives: Our objective was to investigate the cardiac effects of pimobendan in cats with HCM. We hypothesized that pimobendan would not exacerbate left ventricular outflow tract obstructions and that it would improve echocardiographic measures of diastolic function.Animals: Thirteen purpose-bred cats were studied from a research colony with naturally-occurring HCM due to a variant in myosin binding protein C.Methods: Cats underwent two examinations 24 h apart with complete standard echocardiography. On their first day of evaluation, they were randomized to receive oral placebo or 1.25 mg pimobendan 1 h prior to exam. On their second examination, they were crossed over and received the remaining treatment. Investigators were blinded to all treatments.Results: The pimobendan group had a significant increase in left atrial fractional shortening (pimobendan group 41.7% ± 5.9; placebo group 36.1% ± 6.0; p = 0.04). There was no significant difference in left ventricular outflow tract (LVOT) velocities between the groups (pimobendan group 2.8 m/s ± 0.8; placebo group 2.6 m/s ± 1.0). There were no significant differences between the number of cats with LVOT obstructions between groups (12 in pimobendan group; 11 in placebo group; p = 1.00). There were no detectable differences in any systolic measures, including left ventricular fractional shortening, mitral annular plane systolic excursion, and tricuspid annular plane systolic excursion. Doppler-based diastolic function assessment was precluded by persistent tachycardia.Conclusions: Improved left atrial function in the pimobendan group could explain some of the reported survival benefit for HCM cats in CHF. Pimobendan did not exacerbate LVOT obstructions and thus may not be contraindicated in HCM cats with LVOT obstructions. Future studies are needed to better characterize other physiologic effects, particularly regarding diastolic function assessment, and to better assess safety of pimobendan over a longer time-course.

Correlation between qrs duration and cardiac output measured by left ventricular outflow tract velocity in patient with cardiac resynchronization therapy

Correlation between qrs duration and cardiac output measured by left ventricular outflow tract velocity in patient with cardiac resynchronization therapy

Surgical Treatment for Hypertrophic Obstructive Cardiomyopathy with Concomitant Mitral Valve Abnormalities: A Cohort of 26 Cases.

We sought to analyze the pathological characteristics of hypertrophic obstructive cardiomyopathy (HOCM) with concomitant mitral valve abnormalities and to discuss the surgical treatment strategies. The clinical data of 26 HOCM patients treated from January 2014 to March 2016 were retrospectively analyzed. There were 19 males and 7 females with a mean age of 47 ± 16 years (range, 10-70 years). Echocardiography showed HOCM, systolic anterior motion of the mitral apparatus, and concomitant mitral regurgitation. Modified Morrow procedure with expanded resection area was performed in 21 patients. Concomitant mitral valvuloplasty was performed in 4 patients, coronary artery bypass grafting was performed in one patient, and aortic valve replacement was performed in one patient. Echocardiography was performed intraoperatively at postoperative 1 week and at postoperative 1 year to evaluate the left ventricular obstruction and the mitral regurgitation. The left ventricular outflow tract gradient, left ventricular outflow tract velocity, septal thickness, and mitral regurgitation area decreased significantly at postoperative 1 week and 1 year in comparison with the baseline (all P < .001). The postoperative mitral regurgitation and systolic anterior motion of the mitral apparatus were completely abolished or significantly relieved. Only one patient had moderate mitral regurgitation of 7 cm2 after the surgery. At postoperative 1 year, all patients were asymptomatic, and the quality of life was significantly improved. The New York Heart Association (NYHA) class was I-II. Echocardiography showed good anatomy and function of the mitral valve. Concomitant mitral valve abnormality is not uncommon in HOCM. Septal myectomy can adequately expand the left ventricular outflow tract and abolish mitral regurgitation and systolic anterior motion of the mitral apparatus. Concomitant mitral valvuloplasty is indicated for severe congenital abnormalities or secondary lesions of the mitral valve, and the outcomes are satisfactory.

Bedside Echocardiography and Passive Leg Raise as a Measure of Volume Responsiveness in the Emergency Department.

The aim of this study was to investigate the value of bedside echocardiography with a passive leg raise as a noninvasive marker of volume responsiveness. This work was a prospective observational study of patients with end-stage renal disease presenting to the emergency department. The left ventricular outflow tract (LVOT) velocity time integral (VTI) was obtained. Measurements before and after dialysis as well as before and after the passive leg raise were recorded. Fifty-four patients were enrolled, in whom the mean volume of fluid removed ± SD was 3.89 ± 0.91 L. In the predialysis cohort, the mean LVOT VTI was 28.05 cm (95% confidence interval [CI], 26.55-29.55 cm). After the passive leg raise, the mean VTI was 28.52 cm (95% CI, 26.98-30.07 cm). In the postdialysis cohort, the mean VTI was 30.31 cm (95% CI, 28.92-31.69 cm), and it increased to 34.91 cm (95% CI, 33.11-36.72 cm) after the passive leg raise. The Δ VTI values were 1.83% (95% CI, 0.12%-3.55%) in the predialysis group and 15.05% (95% CI, 12.76%-17.34%) in the postdialysis cohort. When stratified by fluid removal, the mean Δ VTI values after hemodialysis were 12.64% (95% CI, 9.79%-15.49%) and 16.84% (95% CI, 13.47%-20.22%) for patients who had less than 4 L and 4 L or greater removed, respectively. In patients without congestive heart failure, the Δ VTI was 15.28% (95% CI, 12.25%-18.32%), whereas for those with congestive heart failure, the mean change was 14.63% (95% CI, 10.91%-18.35%). The LVOT VTI in conjunction with a passive leg raise seems to correlate with the volume status and volume responsiveness.

Predictors of aortic stenosis severity reclassification using an imaging data fusion method in patients referred for transcatheter aortic valve implantation

The use of imaging data fusion method (IDFM) with multislice computed tomography (MSCT) and two-dimensional transthoracic echocardiography (2D-TTE) in patients with aortic stenosis (AS) may result in reclassification of AS severity from severe to non-severe. We sought to establish potential predictors of AS severity reclassification using the IDFM method. A total of 54 high-risk patients (mean age 79 ± 7.9 years; 40.7% male) with severe AS by 2D-TTE (indexed aortic valve area [AVAi] < 0.6 cm2/m2), referred for transcatheter aortic valve implantation, were included in the analysis. AVAi was subsequently recalculated using IDFM by replacing 2D-TTE left ventricular outflow tract (LVOT) measurements with MSCT LVOT parameters. Imaging data fusion method reclassified 20.4% patients into the potentially non-severe AS group. In a multivariable model including clinical variables, reclassification to non-severe AS by IDFM was independently associated with younger age and diabetes mellitus (DM), (odds ratio [OR] 0.864; 95% confidence interval [CI] 0.76-0.99; p < 0.035 and OR 19.259; 95% CI 2.28-162.41; p < 0.007, respectively). In a multivariable analysis of echocardiographic variables, reclassification was associ-ated with higher LVOT velocity time integral and lower aortic mean gradient (OR 1.402; 95% CI 1.07-1.84; p < 0.014 and OR 0.858; 95%: CI 0.760-0.968; p < 0.013, respectively). In addition, 24.1% of patients were reallocated from low-flow (< 35 mL/m2) to normal-flow AS. Imaging data fusion method reclassified a substantial proportion of patients with severe AS into a potentially moderate AS group and from a low-flow to a normal-flow AS group. Such regrouping calls for increased diagnostic prudence in AS patients, especially those with specific clinical and echocardiographic predictors of reclassification, such as DM or low aortic mean gradient.

Validation of “left ventricular early inflow-outflow index”: A novel echocardiographic method for quantification of mitral regurgitation in an Indian population with special focus on rheumatic etiology

BackgroundQuantification of mitral regurgitation (MR) has always required an “integrated approach” as there is no single gold-standard method. We investigated a new Doppler-derived parameter “left ventricular early inflow-outflow index (LVEIO)” for the quantification of MR and its likelihood to predict severe MR in correlation with already established parameters in an Indian population including a large subset of patients with rheumatic etiology. MethodsA prospective study was performed at a major tertiary care center in western India over a 5-month period. Five hundred patients diagnosed with isolated MR including 260 (52%) patients with rheumatic etiology were included in the study after applying exclusion criteria. We analyzed MR using color flow jet, effective regurgitant orifice area (EROA), and vena contracta (VC) width. LVEIO is a simplification of the regurgitant volume (RV) method, which was calculated as “E velocity divided by LV outflow velocity integrated over the systolic ejection period left ventricular outflow tract velocity time integral” and compared with the established parameters. ResultsLVEIO was 4.65 ± 1.45, 6.56 ± 1.52, and 9.91 ± 3.70 among patients diagnosed with mild, moderate, and severe MR, respectively (p < 0.001). Those with LVEIO ≥8 were the most likely to have severe MR (positive likelihood ratio: 10.42). LVEIO had specificity of 93.25% for diagnosis of severe MR with positive predictive value of 86.36%. There was positive correlation observed between LVEIO and VC width (r = 0.591), RV (r = 0.410), and EROA (r = 0.778) (all p < 0.001) in the Pearson correlation test. The specificity of LVEIO remained consistent in diagnosing severe MR in patients with rheumatic etiology. ConclusionLVEIO is a simple yet specific Doppler echocardiographic parameter for estimation of severity of MR including that of rheumatic etiology.

Accuracy of changing rate of left ventricular outflow tract velocity time integral in predicting fluid responsiveness in septic patients

Objective To evaluate the accuracy of changing rate of the left ventricular outflow tract velocity time integral (△VTI) in predicting fluid responsiveness in septic patients. Methods Twenty patients diagnosed with sepsis or septic shock and received mechanical ventilation, aged more than or equal to 18 yr, in whom the ventilation mode was SIMV plus VC, were enrolled in this study.The left ventricular outflow tract VTI, stroke volume (SV) and cardiac output (CO) were measured using ultrasound.Sodium potassium magnesium calcium and glucose injection 100 ml was intravenously infused over 1 min, ultrasound measurement was completed within 1 min, and then Sodium potassium magnesium calcium and glucose injection 400 ml was intravenously infused over 14 min.Fluid responsiveness was defined as increase in SV or CO more than 15% after infusion of 500 ml colloid solution, and then the patients were divided into responsiveness group and non-responsiveness group.△VTI, △SV and △CO were calculated after fluid replacement with 100 ml solution.The receiver operating characteristic curve was used to assess the accuracy of △VTI, △SV and △CO in predicting fluid responsiveness. Results The areas under the receiver operating characteristic curve of △VTI, △SV and △CO were 0.95, 0.91 and 0.88, respectively.When △VTI≥10% was used as the cut-off point, the sensitivity and specificity of △VTI in predicting fluid responsiveness was 90% and 80%, respectively. Conclusion △VTI can accurately predict the fluid responsiveness in septic patients. Key words: Blood flow velocity; Sepsis; Vascular capacitance

Non-invasive measurement of cardiac output in children with repaired coarctation of the aorta using electrical cardiometry compared to transthoracic Doppler echocardiography

Objective: To evaluate the equivalence of the ICON® electrical cardiometry (EC) haemodynamic monitor to measure cardiac output (CO) relative to transthoracic Doppler echocardiography (TTE) in paediatric patients with repaired coarctation of the aorta (CoA). Approach: A group of n = 28 CoA patients and n = 27 matched controls were enrolled. EC and TTE were performed synchronously on each participant and CO measurements compared using linear regression and Bland–Altman analysis. The CoA group was further subdivided into two groups, with n = 10 and without n = 18 increased left ventricular outflow tract velocity (iLVOTv) for comparison. Main results: CO measurements from EC and TTE in controls showed a strong correlation (R = 0.80, p < 0.001) and an acceptable percentage error (PE) of 28.1%. However, combining CoA and control groups revealed a moderate correlation (R = 0.57, p < 0.001) and a poor PE (44.2%). We suspected that the CO in a subset of CoA participants with iLVOTv was overestimated by TTE. Excluding the iLVOTv CoA participants improved the correlation (R = 0.77, p < 0.001) and resulted in an acceptable PE of 31.2%. Significance: CO measurements in paediatric CoA patients in the absence of iLVOTv are clinically equivalent between EC and TTE. The presence of iLVOTv may impact the accuracy of CO measurement by TTE, but not EC.

Association of Left Atrial Function Index with Atrial Fibrillation and Cardiovascular Disease: The Framingham Offspring Study.

BackgroundLeft atrial (LA) size, a marker of atrial structural remodeling, is associated with increased risk for atrial fibrillation (AF) and cardiovascular disease (CVD). LA function may also relate to AF and CVD, irrespective of LA structure. We tested the hypothesis that LA function index (LAFI), an echocardiographic index of LA structure and function, may better characterize adverse LA remodeling and predict incident AF and CVD than existing measures.Methods and ResultsIn 1786 Framingham Offspring Study eighth examination participants (mean age, 66±9 years; 53% women), we related LA diameter and LAFI (derived from the LA emptying fraction, left ventricular outflow tract velocity time integral, and indexed maximal LA volume) to incidence of AF and CVD on follow‐up. Over a median follow‐up of 8.3 years (range, 7.5–9.1 years), 145 participants developed AF and 139 developed CVD. Mean LAFI was 34.5±12.7. In adjusted Cox regression models, lower LAFI was associated with higher risk of incident AF (hazard ratio=3.83, 95% confidence interval=2.23–6.59, lowest [Q1] compared with highest [Q4] LAFI quartile) and over 2‐fold higher risk of incident CVD (hazard ratio=2.20, 95% confidence interval=1.32–3.68, Q1 versus Q4). Addition of LAFI, indexed maximum LA volume, or LA diameter to prediction models for AF or CVD did not significantly improve model discrimination for either outcome.ConclusionsIn our prospective investigation of a moderate‐sized community‐based sample, LAFI, a composite measure of LA size and function, was associated with incident AF and CVD. Addition of LAFI to the risk prediction models for AF or CVD, however, did not significantly improve their performance.

Change of heart dimensions and function during pregnancy in goats

The study aimed to evaluate the effect of pregnancy on heart diameters and function in goats. Transthoracic echocardiography of 12 female dairy goats of two Polish regional breeds was performed. A Mindray M7 diagnostic ultrasound system with Phased Array transducer was used. Simultaneously, electrocardiography was recorded. All animals were examined four times – at mating season, at the end of the first trimester, at the end of the second trimester and just before kidding. Eleven measurements were taken each time: aortic and left atrial diameter (AoD and LAD), right and left ventricular internal diameter in diastole (RVIDd and LVIDd), left ventricular internal diameter in systole (LVIDs), inter-ventricular septum thickness in diastole and systole (IVSd and IVSd) and left ventricular posterior wall in diastole and systole (LVPWd and LVPWs), maximum left and right ventricular outflow tract velocity (RVOT Vmax and LVOT Vmax). Nine consecutive measurements were derived: the ratio of the left atrial diameter to the aortic diameter (AoD/LAD), left ventricular fractional shortening (FS%), left ventricular ejection fraction (EF%), maximum outflow tract pressure gradients (RVOT PGmax and LVOT PGmax), left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV), stroke volume (SV) and cardiac output (CO). HR, LAD, LVPWs, IVSs increased significantly in the first trimester. AoD and RVIDd were significantly higher around parturition. LVIDd, FS%, EF%, SV and CO rose both in the first and third trimester. No measurement decreased during pregnancy. The study confirms that pregnancy causes changes in the heart size and functioning.

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

To 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. A prospective, descriptive, multicenter study was performed. Five intensive care units from university hospitals. Patients older than 17 years needing mechanical ventilation and invasive hemodynamic monitoring were included. LVOT 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. The relation between LVOT VTI and SVI was tested by linear regression analysis. One 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. LVOT 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.

What is the Utility of the Mitral to Left Ventricular Outflow Tract Velocity Time Integral Ratio as a Non–Geometric Indicator of Differential Flow in Isolated Severe Primary and Secondary Mitral Regurgitation?

What is the Utility of the Mitral to Left Ventricular Outflow Tract Velocity Time Integral Ratio as a Non–Geometric Indicator of Differential Flow in Isolated Severe Primary and Secondary Mitral Regurgitation?