Ventricular Volume Measurements Research Articles

Diagnostic value of three-dimensional contrast-enhanced echocardiography for left ventricular volume and ejection fraction measurement in patients with poor acoustic windows: An echo MRI comparison

Diagnostic value of three-dimensional contrast-enhanced echocardiography for left ventricular volume and ejection fraction measurement in patients with poor acoustic windows: An echo MRI comparison

Impact of Epoetin Alfa on Left Ventricular Structure, Function, and Pressure Volume Relations as Assessed by Cardiac Magnetic Resonance: The Heart Failure Preserved Ejection Fraction (HFPEF) Anemia Trial

Anemia, a common comorbidity in older adults with heart failure and a preserved ejection fraction (HFPEF), is associated with worse outcomes. The authors quantified the effect of anemia treatment on left ventricular (LV) structure and function as measured by cardiac magnetic resonance (CMR) imaging. A prospective, randomized single-blind clinical trial (NCT NCT00286182) comparing the safety and efficacy of epoetin alfa vs placebo for 24 weeks in which a subgroup (n=22) had cardiac magnetic resonance imaging (MRI) at baseline and after 3 and 6 months to evaluate changes in cardiac structure and function. Pressure volume (PV) indices were derived from MRI measures of ventricular volume coupled with sphygmomanometer-measured pressure and Doppler estimates of filling pressure. The end-systolic and end-diastolic PV relations and the area between them as a function of end-diastolic pressure, the isovolumic PV area (PVAiso), were calculated. Patients (75±10 years, 64% women) with HFPEF (EF=63%±15%) with an average hemoglobin of 10.3±1.1 gm/dL were treated with epoetin alfa using a dose-adjusted algorithm that increased hemoglobin compared with placebo (P<.0001). As compared with baseline, there were no significant changes in end-diastolic (-7±8 mL vs -3±8 mL, P=.81) or end-systolic (-0.4±2 mL vs -0.7±5 mL, P=.96) volumes at 6-month follow-up between epoetin alfa compared with placebo. LV function as measured based on EF (-1.5%±1.6% vs -2.6%±3.3%, P=.91) and pressure volume indices (PVAiso-EDP at 30 mm Hg, -5071±4308 vs -1662±4140, P=.58) did not differ between epoetin alfa and placebo. Administration of epoetin alfa to older adult patients with HFPEF resulted in a significant increase in hemoglobin, without evident change in LV structure, function, or pressure volume relationships as measured quantitatively using CMR imaging.

Evaluation of automated measurement of left ventricular volume by novel real-time 3-dimensional echocardiographic system: Validation with cardiac magnetic resonance imaging and 2-dimensional echocardiography

BackgroundTraditional 3-dimensional echocardiography (3DE) with volumetric scanning technique requires several heart cycles for full-volume acquisition and complicated manual contouring of left ventricular (LV) endocardium. The new real-time 3DE (RT3DE) system allows acquisition of an instantaneous full-volume dataset in a single heart cycle and automated measurement of LV volume by the algorithm software. However, it has not been evaluated adequately whether automated measurement by RT3DE has better agreement with cardiac magnetic resonance imaging (CMR) than 2-dimensional echocardiography (2DE) with CMR. PurposeThis study aimed to evaluate the accuracy of automated measurement of LV volume using RT3DE compared with 2DE and CMR. Methods and resultsForty-four consecutive patients who underwent RT3DE, 2DE, and CMR were evaluated in this study. The feasibility of automated measurement by RT3DE was 93.2% and the mean operation time was 6min. LV volume and ejection fraction (EF) from semi-automated measurement [end-diastolic volume: r=0.96, limits of agreement (LOA) −30.5 to 39.3ml; end-systolic volume: r=0.97, LOA −22.6 to 32.7ml; EF: r=0.90, LOA −16.1 to 14.2%, respectively] had better agreement with CMR than those from 2DE (r=0.87, LOA −50.5 to 72.2ml; r=0.93, LOA −34.1 to 65.2ml; r=0.89, LOA −20.9 to 10.0%, respectively). ConclusionSemi-automated measurement by RT3DE has better agreement with CMR than 2DE in LV volume and EF. In addition, it is simple to operate and acceptable in feasibility for the clinical setting although there may be room for further learning required to incorporate small hypertrophic LV into the automated algorithm software.

Interstudy variability in cardiac magnetic resonance imaging measurements of ventricular volume, mass, and ejection fraction in repaired tetralogy of fallot: A prospective observational study

To assess the interstudy variability of cardiac magnetic resonance imaging (CMR) parameters of ventricular size and function in repaired tetralogy of Fallot (TOF). Patients with TOF (n = 30, median age 23.5 years, 43% male) were enrolled prospectively. Each patient underwent two consecutive CMR examinations on the same day. Each examination was analyzed for ventricular size and function by two observers and multiple comparisons were made with assessment of agreement using Bland-Altman analysis and intraclass correlation coefficients (ICC). Agreement for most measures of ventricular size and function was high when a single observer analyzed both studies. Agreement was worse when different observers analyzed sequential studies. This effect was most prominent on measurements of right ventricular (RV) mass and there was slight improvement when mass was measured during systole. Aside from ventricular mass, agreement was similar for RV and left ventricular (LV) parameters. CMR measures of ventricular size and function have acceptable repeatability across serial examinations in patients with repaired TOF. Measurements of RV mass are subject to higher variability. For most parameters, agreement limits are wider when measurements are performed by multiple operators. These results will aid in the interpretation of study-to-study variations in the follow-up of individual patients and in designing future clinical trials.

Improved Cardiac MRI Volume Measurements in Patients with Tetralogy of Fallot by Independent End-Systolic and End-Diastolic Phase Selection

ObjectivesTo investigate to what extent cardiac MRI derived measurements of right ventricular (RV) volumes using the left ventricular (LV) end-systolic and end-diastolic frame misrepresent RV end-systolic and end-diastolic volumes in patients with tetralogy of Fallot (ToF) and a right bundle branch block.MethodsSixty-five cardiac MRI scans of patients with ToF and a right bundle branch block, and 50 cardiac MRI scans of control subjects were analyzed. RV volumes and function using the end-systolic and end-diastolic frame of the RV were compared to using the end-systolic and end-diastolic frame of the LV.ResultsTiming of the RV end-systolic frame was delayed compared to the LV end-systolic frame in 94% of patients with ToF and in 50% of control subjects. RV end-systolic volume using the RV end-systolic instead of LV end-systolic frame was smaller in ToF (median −3.3 ml/m2, interquartile range −1.9 to −5.6 ml/m2; p<0.001) and close to unchanged in control subjects. Using the RV instead of LV end-systolic and end-diastolic frame hardly affected RV end-diastolic volumes in both groups and ejection fraction in control subjects (54±4%, both methods), while increasing ejection fraction from 45±7% to 48±7% for patients with ToF (p<0.001). QRS duration correlated positively with the changes in the RV end-systolic volume (p<0.001) and RV ejection fraction obtained in ToF patients when using the RV instead of the LV end-systolic and end-diastolic frame (p = 0.004).ConclusionFor clinical decision making in ToF patients RV volumes derived from cardiac MRI should be measured in the end-systolic frame of the RV instead of the LV.

Transaxial or short axis right ventricular volume measurements - which method correlates more closely with main pulmonary artery flow values in children aged 9 years?

Background In adults right ventricular (RV) measurements from datasets acquired in the transaxial orientation have been found to be more accurate and reproducible than in the short axis plane. Cardiovascular magnetic resonance imaging (CMRI) in children is prone to image misregistration due to less consistent breath-holding which may be more problematic when imaging in the transaxial plane. This study aimed to determine the most accurate method for RV volume evaluation in children. Methods 216 healthy children aged 9 years underwent CMRI as part of a study of developmental influences on cardiovascular structure and function. Contiguous steady state free precession breath-hold cine images were obtained to cover the RV in both short axis and transaxial planes. RV stroke volumes (SV) were compared with flow data derived from phase contrast velocity flow mapping sequences through the main pulmonary artery (MPA). Results

Comparison of echocardiography with dual-source computed tomography for assessment of left ventricular volume in healthy Beagles

To compare echocardiographic measurements of left ventricular (LV) volume obtained via a modified Simpson or Teichholz method with those obtained via dual-source CT (DSCT). 7 healthy Beagles. Each dog was anesthetized for DSCT; LV volume was determined from contrast-enhanced images of the LV lumen during all phases of contraction. Echocardiography was performed with dogs awake and anesthetized. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume, and ejection fraction were measured via a modified Simpson method and Teichholz method. Each dog was anesthetized twice with a 1-week interval between anesthetic sessions. Results obtained while dogs were anesthetized revealed that the modified Simpson method underestimated LV volume (mean ± SD EDV, 24.82 ± 2.38 mL; ESV, 12.24 ± 1.77 mL), compared with that estimated by the Teichholz method (EDV, 32.57 ± 2.85 mL; ESV, 14.87 ± 2.09 mL) or DSCT (EDV, 34.14 ± 1.57 mL; ESV, 16.71 ± 0.76 mL). Ejection fraction (modified Simpson method, 48.53% ± 4.24%; Teichholz method, 54.33% ± 4.26%; DSCT, 51.00% ± 2.71%) differed significantly among the 3 methods. Echocardiographic results obtained while dogs were awake revealed that EDV, ESV, and stroke volume differed significantly between the modified Simpson and Teichholz methods. LV volume determined via the Teichholz method was more similar to that determined via DSCT than was the LV volume determined via the modified Simpson method. The modified Simpson method underestimated LV volume, compared with that obtained via the Teichholz method, in both anesthetized and awake dogs.

Left ventricular distensibility does not explain impaired exercise capacity in pediatric heart transplant recipients

Despite improved ventricular function after heart transplantation, the aerobic capacity, as measured by peak oxygen consumption (VO(2 peak)) of pediatric heart transplant recipients (HTRs), remains 30% to 50% lower than age-matched healthy individuals. Research in adult HTRs suggests that diastolic dysfunction is a major determinant of exercise intolerance; however, it is unknown whether the impaired VO(2 peak) in younger HTRs is due to reduced left ventricular (LV) distensibility. Eight HTRs (mean age, 15 years; mean time post-transplant, 7 years) and 8 matched healthy controls were studied. To evaluate LV distensibility, echocardiographic measurements of ventricular volumes were obtained in 3 positions: supine, head-up tilt, and head-down tilt. Subsequently, participants underwent exercise stress testing to evaluate VO(2 peak). As expected, VO(2 peak) was 26% lower in HTRs (p<0.05). Ventricular volumes in each position were small in HTRs (p = 0.01); however, the percentage change in LV end-diastolic volume indexed (EDVi) to body surface area after the transition from supine to head-up tilt and from head-up tilt to head-down tilt were similar between HTRs (p = 0.956) and controls (p = 0.801). The change in EDVi during the transition from head-up tilt to head-down tilt (LV distensibility) strongly predicted VO(2 peak) in patients (R(2) = 0.614, p = 0.021) and controls (R(2) = 0.510, p = 0.047). Importantly, the slope of this relationship did not differ between HTRs (1.01) and controls (0.977; p = 0.951). LV distensibility does not appear to be a major determinant of exercise intolerance in young HTR.

Abstract 9089: Impact of Semiautomated Border Tracking on the Analysis Time and the Accuracy of Right Ventricular Volume Measurements Using DICOM Gradient Cine MR Datasets

Background: Right ventricular (RV) volume measurements on MR images require significant time for tracing multiple short axis planes and is subject to errors due to through plane motion of tricuspid plane, which limits routine clinical application. We tested a new 3D method of RV volume estimation using semiautomated border tracking to reduce both errors and analysis time. Methods: We studied 20 latex RV shaped models of different sizes (25-225ml). Each RV model was driven by a calibrated pulsatile pump at 3-5 different stroke volumes (SV, 20-80ml). Motion of the RV model was scanned for gradient cine stacks in multiple short axis, sagittal and coronal planes with a 3T Siemens MR Scanner. Image data was analyzed on an offline RV analysis program embedded in Research Arena VA® (TomTec). Each cine loop was analyzed with manual tracing employing automated border tracking. Datasets were then analyzed for RV volume after manual editing of borders at each short axis level. Results: Semiautomated tracking used 3-5 minutes rather than the manual 30-45 minutes. Both methods overestimated ESV and underestimated SV but showed a positive linear correlation (r = 0.80 &amp; 0.87 for ESV and 0.85 &amp; 0.89 for SV respectively) compared to reference values, and good interobserver variability (r = 0.92 &amp; 0.77 respectively). Bland-Altman analysis showed slightly lower bias for manual editing (3.45±0.80) compared to automated tracking (5.25±1.45) but all data points were within 95% confidence intervals. Conclusions: The new RVMR program is a user friendly semiautomated program that may be used for clinical assessment of RV volumes.

ASSESSMENT OF LEFT VENTRICULAR STRUCTURE AND FUNCTION IN SLEEP APNOEA SYNDROME PATIENTS WITH ECHOCARDIOGRAPHY

ObjectivesIt is well known that sleep apnoea syndrome (SAS) is associated with various medical problems that have an impact on cardiovascular mortality and morbidity. But it is seldom reported that...

Improving the reproducibility of MR-derived left ventricular volume and function measurements with a semi-automatic threshold-based segmentation algorithm

To validate a novel semi-automatic segmentation algorithm for MR-derived volume and function measurements by comparing it with the standard method of manual contour tracing. The new algorithms excludes papillary muscles and trabeculae from the blood pool, while the manual approach includes these objects in the blood pool. An epicardial contour served as input for both methods. Multiphase 2D steady-state free precession short axis images were acquired in 12 subjects with normal heart function and in a dynamic anthropomorphic heart phantom on a 1.5 T MR system. In the heart phantom, manually and semi-automatically measured cardiac parameters were compared to the true end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF). In the subjects, the semi-automatic method was compared to manual contouring in terms of difference in measured EDV, ESV, EF and myocardial volume (MV). For all measures, intra- and inter-observer agreement was determined. In the heart phantom, EDV and ESV were underestimated for both the semi-automatic. As the papillary muscles were excluded from the blood pool with the semi-automatic method, EDV and ESV were approximately 20 ml lower in the patients, whereas EF was approximately 16 % higher. Intra- and inter-observer agreement was overall improved with the semi-automatic method compared to the manual method. Correlation between manual and semi-automatic measurements was high (EDV: R = 0.99, ESV: R = 0.96; EF: R = 0.80, MV: R = 0.99). The semi-automatic method could exclude endoluminal muscular structures from the blood volume with significantly improved intra- and inter-observer variabilities in cardiac function measurements compared to the conventional, manual method, which includes endoluminal structures in the blood volume.

Improved Agreement between Experienced and Inexperienced Observers using a Standardized Evaluation Protocol for Cardiac Volumetry and Infarct Size Measurement

To study the agreement between experienced and inexperienced observers before and after training using a standardized evaluation protocol for cardiac magnetic resonance imaging (CMR) measurements of left ventricular (LV) volumes, mass and infarct size. First, 10 CMR studies from patients with myocardial infarction were analyzed by 2 experienced and 4 inexperienced observers in respect to end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), LV mass and infarct size. Subsequently, the inexperienced observers were trained using a standardized evaluation protocol. Thereafter, all observers analyzed another 10 CMR studies. Before training the relative difference between experienced and inexperienced observers was -4.3±8.2% for EDV, -13.3±14.2% for ESV, 5.9±8.2% for EF, -12.2±10.9% for LV mass and -27.0±29.0% for infarct size in gram. After training, agreement significantly improved to 0.2±8.8% for EDV (p<0.05), -2.1±10.9 for ESV (p<0.01), 1.5±6.9% for EF (p<0.05), and -3.6±17.1% for infarct size (p<0.0001), but no improvement was seen for LV mass (-11.2±7.9, p=0.64). A slice based analysis showed, that the variable inclusion of the most basal and apical slices were mainly responsible for the low agreement of the measurements before training. Training using a standardized evaluation protocol significantly improved the agreement between experienced and inexperienced observers for important CMR parameters. The proposed evaluation protocol can be used for training to improve the reproducibility of CMR measurements.

Left ventricular functional assessment in murine models of ischemic and dilated cardiomyopathy using [18 F]FDG-PET: comparison with cardiac MRI and monitoring erythropoietin therapy

BackgroundWe performed an initial evaluation of non-invasive ECG-gated [18 F]FDG-positron emission tomography (FDG-PET) for serial measurements of left ventricular volumes and function in murine models of dilated (DCM) and ischemic cardiomyopathy (ICM), and then tested the effect of erythropoietin (EPO) treatment on DCM mice in a preliminary FDG-PET therapy monitoring study.MethodsMice developed DCM 8 weeks after injection with Coxsackievirus B3 (CVB3), whereas ICM was induced by ligation of the left anterior descending artery. LV volumes (EDV and ESV) and the ejection fraction (LVEF) of DCM, ICM and healthy control mice were measured by FDG-PET and compared with reference standard results obtained with 1.5 T magnetic resonance imaging (MRI). In the subsequent monitoring study, LVEF of DCM mice was evaluated by FDG-PET at baseline, and after 4 weeks of treatment, with EPO or saline.ResultsLV volumes and the LVEF as measured by FDG-PET correlated significantly with the MRI results. These correlations were higher in healthy and DCM mice than in ICM mice, in which LVEF measurements were somewhat compromised by absence of FDG uptake in the area of infarction. LV volumes (EDV and ESV) were systematically underestimated by FDG-PET, with net bias such that LVEF measurements in both models of heart disease exceeded by 15% to 20% results obtained by MRI. In our subsequent monitoring study of DCM mice, we found a significant decrease of LVEF in the EPO group, but not in the saline-treated mice. Moreover, LVEF in the EPO and saline mice significantly correlated with histological scores of fibrosis.ConclusionsLVEF estimated by ECG-gated FDG-PET significantly correlated with the reference standard MRI, most notably in healthy mice and mice with DCM. FDG-PET served for longitudinal monitoring of effects of EPO treatment in DCM mice.

Assessment of right ventricular volumes and function using cardiovascular magnetic resonance cine imaging after atrial redirection surgery for complete transposition of the great arteries

Cardiovascular magnetic resonance (CMR) imaging is the reference standard for measurement of right ventricular (RV) volumes and function. To date, no study has compared methods of data acquisition and analysis by CMR for adults with a systemic RV. Our objective was to evaluate RV size and function using axial and short axis views in adults post atrial switch (Mustard) surgery. A total of 34 adults (20 male, mean age at CMR 32 ± 6 years) were identified at our centre. Volumes, RV end-diastolic (EDV) and end-systolic (ESV) were measured in short axis and axial orientations by two independent experienced readers, blinded to clinical and CMR data. Intra and interobserver measurements in each view were compared using Bland-Altman plots and intraclass correlation coefficients (ICC). Although mean volumes were larger in the axial as compared with the short axis view [RVEDV 247 ± 67 vs. 233 ± 54 ml (p = 0.002) and RVESV 148 ± 54 vs. 136 ± 50 ml (p = 0.001)], mean RV ejection fractions (EF) were similar [41 ± 9 % vs. 43 ± 12 % (p = 0.13)]. Bland-Altman plots demonstrated better agreement for axial measures of RVEDV and right ventricular ejection fraction (RVEF) within and between observers. Similarly, ICC values were stronger for axial as compared with short axis volumes and function-intraobserver RVEDV 0.99 (0.98-0.99) versus 0.96 (0.92-0.98) and RVEF 0.96 (0.93-0.98) versus 0.90 (0.82-0.95); interobserver RVEDV 0.97 (0.94-0.98) versus 0.90 (0.73-0.95) and RVEF 0.85 (0.53-0.94) versus 0.82 (0.67-0.90). Axially derived measurements of RV volumes and function have better agreement and reproducibility as compared with short axis values; whereas axial volumes tend to be larger, RVEF is not significantly different between the two methods.

Significant Bias Associated with Left Ventricular Volume Measurements by MRI Compared to Echo (2D, 2D-Contrast and 3D)—A Systematic Review

Significant Bias Associated with Left Ventricular Volume Measurements by MRI Compared to Echo (2D, 2D-Contrast and 3D)—A Systematic Review

Outcomes of left ventricular reconstruction when established parameters are followed, and subsequent questions

The 2010 Task Force guidelines from the European Society of Cardiology/European Association of Cardiothoracic Surgery (ESC/EACTS) recommend ‘consideration of surgical ventricular restoration (SVR) to treat ischemic dilated cardiomyopathy, following measurement of ventricular volume and assessment of myocardial scar in centers with high experience’ [1]. This issue contains a report by Cho et al. [2] concerning ‘Long-term results and mid-term features of left ventricular reconstruction procedures on left ventricular volume, geometry, function and mitral regurgitation’ that amplifies the importance of surgical ventricular restoration (SVR) to architecturally remedy the failing hearts of patients with ischaemic dilated cardiomyopathy. Their superb results confirm how this procedure carries a very low perioperative mortality (1.6%), dramatically diminishes rehospitalization for cardiac causes over a 7-year interval and allows 79% long-term survival. These beneficial results are in concert with the broad number of world-wide SVR reports [3] and thus provide yet another contradiction to the flawed Surgical Treatment for Ischemic Heart Failure (STICH) study [4], whose misguided results have caused global curtailment of properly treating ischaemic dilated cardiomyopathy. Cho et al. precisely followed the benchmark SVR entry criteria of >60 ml/m left ventricular end-systolic volume index (LVESVI), >35% scarring of the left ventricle (LV) perimeter and achieved the requisite 40% reduction of ventricular volume to reduce the LVESVI of <60 ml/m. These SVR-induced changes show why LVESVI <60 ml/m is an independent predictor of prognosis [5], as the very low 7-year mortality ‘resulted from the natural events of neoplasm and infection’ rather than from pump failure or sudden death. These splendid results were similarly achieved by the Dor, linear closure and septal anterior ventricular exclusion (SAVE) procedures, yet each outcome was accompanied by creating a more spherical ventricle instead of the intended elliptical form. Confirmation of improved systolic performance was garnered from the increased systolic eccentricity index that indicated the smaller remote muscle contracted more efficiently as it became more helical during ejection. Moreover, late findings in patients with larger pre-SVR ventricular volumes showed the development of a 22% incidence of mitral regurgitation (MR), which parallels Di Donato’s report of 38% later mitral insufficiency in patients with even larger preoperative ventricular volumes [6]. These shape and MR change direct attention towards how the procedure execution influenced these findings, since Pocar recently pointed out the disadvantage of a more spherical chamber and functional MR [7].

Real Time 3D echocardiography (RT3D) for assessment of ventricular and vascular function in hypertensive and heart failure patients

BackgroundCardiac and systemic hemodynamics have been historically in the domain of invasive cardiology, but recent advances in real-time 3-Dimensional echocardiography (RT3D echo) provide a reliable measurement of ventricular volumes, allowing to measure a set of hemodynamic parameters previously difficult or impossible to obtain with standard 2D echo.AimTo assess the feasibility of a comprehensive hemodynamic study with RT-3D echo.MethodsWe enrolled 136 patients referred for routine echocardiography: 44 normal (N), 57 hypertensive (HYP), and 35 systolic heart failure patients (HF). All patients underwent standard 2D echo examination followed by RT3D echo examination, including measurement of left ventricular (LV) end-diastolic and end-systolic volumes and derived assessment of LV elastance (an index of LV contractility), arterial elastance (characterizing the distal impedance of the arterial system downstream of the aortic valve); ventricular-arterial coupling (a central determinant of net cardiovascular performance); systemic vascular resistances. Blood pressure was derived from cuff sphygmomanometer and heart rate from ECG.ResultsA complete 2D echo was performed in all 136 patients. 3D echo examination was obtained in 130 patients (feasibility = 95 %). Standard 2D echo examination was completed in 14.8 ± 2.2 min. Acquisition of 3D images required an average time of 5 ± 0.9 min (range 3.5-7.5 min) and image analysis was completed in 10.1 ± 2.8 min (range 6–12 min) per patient. Compared to N and HYP, HF patients showed reduced LV elastance (1.7 ± 1.5 mmHg mL-1 m-2, p <0.001 vs N = 3.8 ± 1.3 and HYP = 3.8 ± 1.3) and ventricular-arterial coupling (0.6 ± 0.5, p < 0.01 vs N = 1.4 ± 0.4 and HYP = 1.2 ± 0.4). Systemic vascular resistances were highest in HYP (2736 ± 720, p < .01 vs N = 1980 ± 432 and vs HF = 1855 ± 636 dyne*s/cm5). The LV elastance was related to EF (r = 0.73, p < 0.01) and arterial pressure was moderately related to vascular elastance (r = 0.54, p < 0.01). The ventricular-arterial coupling was unrelated to systemic vascular resistances (r = −0.04, p NS).ConclusionRT-3D echo allows a non invasive, comprehensive assessment of cardiac and systemic hemodynamics, offering insight access to key variables – such as increased systemic vascular resistances in hypertensives and reduced ventricular-arterial coupling in heart failure patients.

Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load

BackgroundLeft ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of left ventricular (LV) contractility.MethodsSeven anesthetised juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon (IVCB) catheter produced controlled load reduction. First and last beats in the sequence of eight were analysed with speckle tracking (STE) during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status. Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal. Paired comparisons were made for different load states using the Wilcoxon’s Signed Rank test.ResultsThe inferior vena cava balloon occlusion (IVCBO) load change compared for first to last beat resulted in LV twist increase (11.67° ±2.65° vs. 16.17° ±3.56° respectively, p < 0.004) during the load alteration and under adrenaline stimulation LV twist increase 12.56° ±5.1° vs. 16.57° ±4.6° (p < 0.013), and though increased, didn’t reach significance in negative inotropic condition. Untwisting rate increased significantly at baseline from −41.7°/s ±41.6°/s vs.−122.6°/s ±55.8°/s (P < 0.039) and under adrenaline stimulation untwisting rate increased (−55.3°/s ±3.8°/s vs.−111.4°/s ±24.0°/s (p < 0.05), but did not systematically changed in negative inotropic condition.ConclusionsPeak systolic LV twist and peak early diastolic untwisting rate are load dependent. Differences in LV load should be included in the interpretation when serial measures of twist are compared.

Comparison of Left Ventricular Stroke Volume Assessment by Two‐ and Three‐Dimensional Echocardiography in a Swine Model of Acute Myocardial Infarction Validated by Thermodilution Method

Accurate left ventricular stroke volume (LVSV) measurement is clinically important in patients presenting with acute myocardial infarction. Three-dimensional echocardiography (3DE) is expected to overcome limitations of two-dimensional echocardiography (2DE). However, inaccuracy in volumetry by 3DE has often been reported hindering further clinical application. This study aimed at comparing agreement and correlation with the thermodilution method (TDM) between 2DE and 3DE measurement of LVSV. Swine model of myocardial infarction was created and LVSV was measured by 3DE by subtracting end-systolic from end-diastolic volume (3DE-method). Pulsed Doppler ultrasound and left ventricular outlet tract area were used to measure LVSV by 2DE (2DE-method). TDM was performed by the Swan-Ganz catheter. Bland-Altman analysis followed by assessment of intraclass correlation coefficient (ICC) were performed between 2DE-method and TDM as well as 3DE-method and TDM. A total of 25 comparisons revealed a significant overestimation of LVSV by the 2DE-method (bias = 6.5 mL; 95% confidence interval [CI], 3.9-9.0 mL; P < 0.0001), whereas there was no significant bias by the 3DE-method (bias =-1.6; 95% CI, -4.3 to 1.1 mL; P = 0.22). The ICC between 2DE and TDM was 0.49 (95% CI, 0.14-0.74) whereas ICC between 3DE and TDM was 0.75 (95% CI, 0.51-0.88). This study elucidated that LVSV is better estimated by 3DE-method compared to the conventional 2DE-method. This investigation will provide a more accurate, quick and noninvasive way of LVSV and cardiac output assessment at bedside by further application of 3DE.

Planimetric Hematoma Measurement in Patients With Intraventricular Hemorrhage

Reliable quantification of both intracerebral hemorrhage and intraventricular hemorrhage (IVH) volume is important for hemostatic trials. We evaluated the reliability of computer-assisted planimetric volume measurements of IVH. Computer-assisted planimetry was used to quantify IVH volume. Five raters measured IVH volumes, total (intracerebral hemorrhage+IVH) volumes, and Graeb scores from 20 randomly selected computed tomography scans twice. Estimates of interrater and intrarater reliability were calculated and expressed as an intrarater correlation coefficient and an absolute minimum detectable difference. Planimetric IVH volume analysis had excellent intra- and interrater agreement (intrarater correlation coefficient, 0.96 and 0.92, respectively), which was superior to the Graeb score (intrarater correlation coefficient, 0.88 and 0.83). Minimum detectable differences for intra- and interrater volumes were 12.1 mL and 17.3 mL, and were dependent on the total size of the hematoma; hematomas smaller than the median 43.8 mL had lower minimum detectable differences, whereas those larger than the median had higher minimum detectable differences. Planimetric total hemorrhage volume analysis had the best intra- and interrater agreement (intrarater correlation coefficient, 0.99 and 0.97, respectively). Computer-assisted planimetric techniques provide a reliable measurement of ventricular hematoma volume, but are susceptible to higher absolute error when assessing larger hematomas.