Echocardiographic Left Ventricular End-diastolic Volume Research Articles

A Novel Method for Deriving Pressure-Volume Loops in Stable cfLVAD Patients: Validation and Insights into Myocardial Oxygen Consumption, Energetics and Efficiency

Introduction: Assessment of left ventricular (LV) recovery under continuous-flow left ventricular assist device (cfLVAD) support is hampered by concomitant pump support. We describe derivation of non-invasive pressure-volume (PV) loops in cfLVAD patients and demonstrate an application in the assessment of recovery. Methods: Using controller parameters and non-invasive arterial pressure waveforms, central aortic pressure, outflow conduit pressure gradient and instantaneous left ventricular pressure (LVP) were calculated. Instantaneous LV volumes (LVV) were calculated from echocardiographic left ventricular end-diastolic volume (LVEDV) accounting for the integral of pump flow with respect to time and aortic ejection volume derived from the pump speed waveform. PV loops were derived during pump speed adjustment and following bolus intravenous Milrinone to assess changes in loading conditions and contractility respectively. Results: Fourteen patients were studied, generating 77 non-invasive PV loops. Baseline non-invasive LVEDP correlated with invasive PAWP (r2 = 0.57, RMSE 5.0, p = 0.003). Measured non-invasively, Milrinone significantly increased LVEF (40.3 ± 13.6 vs 36.8 ± 14.2%, p < 0.0001), maximum dPdt (623 ± 126 vs 555 ± 122 mmHg/s, p = 0.006), and end-systolic elastance (1.03 ± 0.57 vs 0.89 ± 0.38 mmHg/mL, p = 0.008), consistent with its expected inotropic effect. Milrinone reduced MVO2 (0.15 ± 0.06 vs 0.16 ± 0.07 mL/beat, p = 0.003) and improved myocardial efficiency (43.7 ± 14.0 vs 41.2 ± 15.5%, p = 0.001). Reduced pump speed caused increased LVEDV (190 ± 80 vs 165 ± 71 mmHg, p < 0.0001) and LVEDP (14.3 ± 10.2 vs 9.9 ± 9.3 mmHg, p = 0.024), consistent with a predictable increase in preload. There was increased MVO2 (0.16 ± 0.07 vs 0.14 ± 0.06 mL/beat, p < 0.0001) despite unchanged stroke work (p = 0.24), reflecting decreased myocardial efficiency (39.2 ± 12.7 vs 45.2 ± 17.0%, p = 0.003). Conclusions: Non-invasive PV loops can accurately detect changes in load and contractility, and may help detect LV recovery under cfLVAD support.

Heart-type fatty-acid-binding protein is a prognostic biomarker for sepsis outcome and sepsis-related left-ventricular dysfunction: a comparison with troponin I

Background Using heart-type fatty-acid-binding protein (H-FABP) in critically ill patients provides a superior results than the conventional cardiac biomarkers. Objective The aim of the study was to estimate the prognostic significance of H-FABP in patients with septic shock and the prevalence of sepsis-related myocardial dysfunction in comparison to troponin I. Patients and methods Fifty ICU patients with sepsis were enrolled in this study. All patients were evaluated using Acute Physiology and Chronic Health Evaluation II score on admission and every 24 h during ICU stay. Serum levels of both H-FABP and troponin I were investigated during the first 24 h after admission. Using modified Simpson’s method, echocardiographic left-ventricular end-diastolic volume (LVEDV), left-ventricular end-systolic volume (LVESV), and left-ventricular ejection fraction (LV%EF) were calculated on admission and after 24 h. Results The patients were divided into two groups: group 1, which included 12 patients (mean age: 50.2±21 years) suffering from sepsis; and group 2, which included 38 patients (mean age: 58.4±19.2 years) with septic shock. Compared with group 1, H-FABP of group 2 showed significant higher values (76.3 vs. 33.3% of patients, P Conclusion In septic shock, H-FABP can be used as a prognostic marker for mortality rathar than troponin I. The positive H-FABP patients showed a significant relation with sepsis-related left-ventricular systolic myocardial dysfunction.

Normal Left Ventricular Size in Premature Newborns by the Echocardiographic Bullet Method.

Objective To define the normal range for a novel parameter of left ventricular (LV) size in premature neonates. Study Design We retrospectively analyzed echocardiographic imaging data to produce percentile nomograms and tabular data for Z-score calculation for LV end-diastolic volume (LVEDV) in premature neonates. The utility of LVEDV was compared with the current standard for LV size in patients who were treated for a patent ductus arteriosus (PDA). Results The mean gestational age and weight for the normal (n = 85) and PDA (n = 19) cohorts was 33 ± 5 weeks and 1.96 ± 1.0 kg and 25 ± 2 weeks and 0.87 ± 0.3 kg, respectively. The mean LVEDV of the PDA group (97.7 ± 22.2 mL/m^2.76) was significantly larger than that of reference group (63.0 ± 11.2 mL/m^2.76), p = 0.002. The sensitivity of LVEDV was better (68 vs. 11%) compared with LV dimension (the current standard) in detecting a large LV in the PDA patients. The LVEDV for our reference cohort (63.0 ± 11.2 mL/m^2.76) was smaller than the published normals (70.4 ± 9.1 mL/m^2.76, p &lt; 0.001) for infants. Conclusion Echocardiographic LVEDV can now be utilized to determine the LV size in premature neonates. In patients with a PDA, an elevated LVEDV &gt; +2 Z-scores can serve as objective data to aid in clinical trials and/or management decisions.

Baseline characteristics of patients recruited in the AREA IN-CHF study (Antiremodelling Effect of Aldosterone Receptors Blockade with Canrenone in Mild Chronic Heart Failure)

Excess aldosterone activity contributes to the pathogenesis and progression of heart failure (HF). Aldosterone antagonists improve clinical outcome in patients with severe HF or left ventricular (LV) dysfunction after myocardial infarction, but knowledge of their impact in mild chronic HF is sparse. AREA IN-CHF was planned to investigate the effects of canrenone on progression of LV remodelling in mild HF. AREA IN-CHF is a multicentre, randomised, double-blind, parallel group comparison of canrenone (up to 50 mg/day) versus placebo in mild stable HF. The primary endpoint is change in echocardiographic LV end-diastolic volume over 12 months. Patients had New York Heart Association class II HF, LV ejection fraction < or =45%, stable standard therapy, creatinine < or =2.5 mg/dl, potassium < or =5.0 mmol/l. Follow-up examinations were scheduled monthly for the first 3 months and every 3 months thereafter. Aldosterone was measured at baseline, brain natriuretic peptide and procollagen type III amino-terminal peptide (PIIINP) at baseline and at 6 months. Echocardiography was performed at baseline, at 6 and 12 months. Among 467 patients, median age 64 years (interquartile range (IQR) 56-70 years), 84% were men, 52% had ischaemic HF, 96% were receiving angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, 79% beta-blockers. Brain natriuretic peptide, aldosterone and PIIINP were 88 pg/ml (IQR 35-185 pg/ml), 118 pg/ml (IQR 75-177 pg/ml), and 5.38 microg/l (IQR 3.98-7.14 microg/l), respectively. LV end-diastolic volume was 79 ml/m (IQR 64-105 ml/m) and LV ejection fraction was 40% (IQR 33-45%). The role of aldosterone blockade in patients with mild HF remains to be established. AREA IN-CHF is addressing this issue in a large population on optimal medical therapy.

Value of color Doppler estimation of regurgitant volume in patients with chronic aortic insufficiency

We studied 16 patients with chronic aortic insufficiency to compare a method for measuring regurgitant volume with color Doppler flow mapping to stroke count ratio determined by radionuclide ventriculography and to ventricular volumes assessed by two-dimensional echocardiography. A real-time color flow map of the left ventricular was obtained from an apical two- and five-chamber view and the maximal mosaic pattern of diastolic turbulent flow was planimetered as a reflection of the maximal regurgitant volume using biplane Simpson's rule. The maximal Doppler regurgitant volume evaluated by color Doppler flow mapping correlated with the stroke count ratio measured by scintigraphy ( r = 0.86, SEE = 11 cc). There were significant relationships between maximal regurgitant volume measured by color Doppler and echocardiographic left ventricular end-diastolic volume ( r = 0.88), left ventricular end-systolic volume ( r = 0.77), and left ventricular mass ( r = 0.71). Patients with larger regurgitant volumes tended to have a larger left ventricular end-diastolic volume-to-mass ratio ( r = 0.56). Thus maximal aortic regurgitant volume can be estimated noninvasively with color Doppler flow mapping. The measurement appears to relate to left ventricular morphologic changes occurring in this condition and it may prove to be useful in assessing patients with chronic aortic insufficiency and in determining their long-term management.

One versus two MAC halothane anesthesia does not alter the left ventricular diastolic pressure-volume relationship.

Previous studies on halothane's effect on left ventricular diastolic compliance (LVDC) not only have had conflicting results, but are not directly applicable to most intraoperative settings. Therefore, the authors examined in dogs whether the depth of halothane anesthesia alters LVDC under surgical conditions over a wide range of hemodynamic stresses with the cardiovascular reflexes intact. The left ventricular diastolic pressure-volume relation was examined at 1 MAC and 2 MAC halothane in seven dogs over wide ranges of preload and afterload during left thoracotomy. Pulmonary capillary wedge pressure (PCWP), left ventricular end-diastolic pressure (LVEDP), and echocardiographic left ventricular end-diastolic volume (LVEDV) were analyzed with the exponential pressure-volume relation P = AeBV (where P = pressure, V = volume, and A and B are empirically derived coefficients). Multivariate analysis showed no significant differences for diastolic pressure-volume relations, comparing both levels of halothane using either PCWP or LVEDP for pressure. The authors conclude that in the intact cardiovascular system in the healthy open-chest dog: 1) LVDC does not change with the depth of halothane between 1 and 2 MAC (it is still possible LVDC changed between 0 and 1 MAC), and 2) PCWP does reflect the LVEDV during halothane anesthesia (between 1 and 2 MAC) under surgical conditions over a wide range of cardiovascular stresses.

Quantitative radiocardiography in patients with patent ductus arteriosus.

Analytical models of the analog computer simulation method of radiocardiogram (RCG) were revised to obtain quantitative hemodynamic evaluations in patent ductus arteriosus (PDA). The theoretical and technical aspects are herein outlined, and the effects of clinical application discussed. Twenty-six patients with a left-to-right PDA shunt were studied by the revised RCG models, and the results were compared with oxymetric or echocardiographic data. Between RCG and oxymetry, the systemic blood flow (SBF) findings agreed well (r = 0.91), but in oxymetry, the pulmonary blood flow (PBF) findings were generally seen greater than in RCG (r = 0.81), and the oxymetric shunts appeared larger than in RCG (r = 0.75). This is because oxymetry cannot avoid the direct effects of the uneven partition of shunt flow to the lungs, whereas RCG can, in addition, measure the mean PBFs and SBFs. RCG may thus be said to be superior to oxymetry in assessing PDA shunts. Furthermore, RCG can estimate the mean left and right heart volumes (LHV and RHV) at the same time; the RCG LHV was found to correspond to the echocardiographic left ventricular end-diastolic volume (LVEDV) (r = 0.89). Moreover, the obtained relation between the RHV/LHV (Y) and the shunt ratio (X) proved to be the same that calculated theoretically (Y = -X + 1.0) in uncomplicated patients. Patients not presenting this relation may be assumed to suffer some condition complicating the PDA. In effect, the analog computer simulation method of RCG is a unique non-invasive means of obtaining quantitative analyses in PDA and in other congenital shunt diseases as well.