Assessment Of Left Ventricular Systolic Function Research Articles

Changes in Left Ventricular Function After Mitral Valve Repair for Severe Organic Mitral Regurgitation

Limited data are available on the changes in left ventricular (LV) contractile function at long-term follow-up after mitral valve repair (MVr). Moreover, assessment of LV systolic function in patients undergoing MVr is troublesome with current methods, given that mitral regurgitation is characterized by increased preload and decreased afterload, potentially masking LV dysfunction. The aim of this study was to assess the value of LV global strain (longitudinal and circumferential) measured by speckle tracking analysis for detecting changes in contractile function after MVr. A total of 122 patients with organic mitral regurgitation who underwent successful MVr at an early stage (LV ejection fraction>60%, LV end-systolic diameter<40 mm) were included. Echocardiography was performed at baseline and at short-term (∼7 days) and long-term (1 to 3 years) follow-up after MVr. At baseline, LV ejection fraction and LV global strain were higher in patients than in 40 normal control individuals. By contrast, LV forward stroke volume was higher in control individuals than in patients. At short-term follow-up, a significant decrease in LV ejection fraction and LV global strain was noted as a consequence of changes in loading conditions. At long-term follow-up, LV ejection fraction and LV global strain improved significantly. Correction of LV strain for LV size showed a subtle impairment of myocardial contractility at baseline, which significantly improved over time after MVr, together with the improvement in LV forward stroke volume. Mitral valve repair for organic mitral regurgitation results in a significant increase in LV myocardial contractility as measured by LV global strain corrected by LV size.

Increased myocardial fibrosis and left ventricular dysfunction in Cushing's syndrome

Active Cushing's syndrome (CS) is associated with cardiomyopathy, characterized by myocardial structural, and ultrastructural abnormalities. The extent of myocardial fibrosis in patients with CS has not been previously evaluated. Therefore, the objective of this study was to assess myocardial fibrosis in CS patients, its relationship with left ventricular (LV) hypertrophy and function, and its reversibility after surgical treatment. Fifteen consecutive CS patients (41±12 years) were studied together with 30 hypertensive (HT) patients (matched for LV hypertrophy) and 30 healthy subjects. Echocardiography was performed in all patients including i) LV systolic function assessment by conventional measures and by speckle tracking-derived global longitudinal strain, ii) LV diastolic function assessment using E/E', and iii) myocardial fibrosis assessment using calibrated integrated backscatter (IBS). Echocardiography was repeated after normalization of cortisol secretion (14±3 months). CS patients showed the highest value of calibrated IBS (-15.1±2.5 dB) compared with HT patients (-20.0±2.6 dB, P<0.01) and controls (-23.8±2.4 dB, P<0.01), indicating increased myocardial fibrosis independent of LV hypertrophy. Moreover, calibrated IBS in CS patients was significantly related to both diastolic function (E/E', r=0.79, P<0.01) and systolic function (global longitudinal strain, r=0.60, P=0.02). After successful surgical treatment, calibrated IBS normalized (-21.0±3.8 vs -15.1±2.5 dB, P<0.01), suggestive of regression of myocardial fibrosis. Patients with CS have increased myocardial fibrosis, which is related to LV systolic and diastolic dysfunction. Successful treatment of CS normalizes the extent of myocardial fibrosis. Therefore, myocardial fibrosis appears to be an important factor in the development and potential regression of CS cardiomyopathy.

How should we measure global and regional left ventricular systolic function?

The assessment of left ventricular (LV) systolic function is frequently the most important task during the echocardiography examination. LV ejection fraction (EF) is the most commonly used measure to assess LV systolic function. EF is well established, with strong prognostic and therapeutic implications, but, nevertheless, it may not always be satisfactory in all patients. Other measures of myocardial contractility can provide valuable additive information in some patients. This is particularly true in patients with suspected heart failure but normal EF. The measurement of longitudinal function using M-mode and/or deformation analysis from tissue Doppler data or speckle tracking algorithms can be useful in this respect. Regional LV dysfunction can be difficult to detect using visual semi-quantitative assessment of regional wall motion. Contrast echocardiography can be most helpful in delineating the LV endocardial border and, thus, increasing sensitivity for detecting wall motion abnormalities. Deformation analysis can also be helpful for detecting subtle wall motion abnormalities, but these methods should be used with caution due to measurement variability and image quality dependence.

Assessing left ventricular systolic function in shock: evaluation of echocardiographic parameters in intensive care

IntroductionAssessing left ventricular (LV) systolic function in a rapid and reliable way can be challenging in the critically ill patient. The purpose of this study was to evaluate the feasibility and reliability of, as well as the association between, commonly used LV systolic parameters, by using serial transthoracic echocardiography (TTE).MethodsFifty patients with shock and mechanical ventilation were included. TTE examinations were performed daily for a total of 7 days. Methods used to assess LV systolic function were visually estimated, "eyeball" ejection fraction (EBEF), the Simpson single-plane method, mean atrioventricular plane displacement (AVPDm), septal tissue velocity imaging (TDIs), and velocity time integral in the left ventricular outflow tract (VTI).ResultsEBEF, AVPDm, TDIs, VTI, and the Simpson were obtained in 100%, 100%, 99%, 95% and 93%, respectively, of all possible examinations. The correlations between the Simpson and EBEF showed r values for all 7 days ranging from 0.79 to 0.95 (P < 0.01). the Simpson correlations with the other LV parameters showed substantial variation over time, with the poorest results seen for TDIs and AVPDm. The repeatability was best for VTI (interobserver coefficient of variation (CV) 4.8%, and intraobserver CV, 3.1%), and AVPDm (5.3% and 4.4%, respectively), and worst for the Simpson method (8.2% and 10.6%, respectively).ConclusionsEBEF and AVPDm provided the best, and Simpson, the worst feasibility when assessing LV systolic function in a population of mechanically ventilated, hemodynamically unstable patients. Additionally, the Simpson showed the poorest repeatability. We suggest that EBEF can be used instead of single-plane Simpson when assessing LV ejection fraction in this category of patients. TDIs and AVPDm, as markers of longitudinal function of the LV, are not interchangeable with LV ejection fraction.

Assessment of left ventricular regional and global systolic function in patients with coronary artery disease using strain parameter of velocity vector imaging

Objective To assess left ventricular(LV) regional and global systolic function of patients with coronary artery disease using strain parameter of velocity vector imaging(VVI) technique in quiescent condition. Methods Thirty patients with coronary artery disease and 30 healthy volunteers were enrolled in this study. The two-dimensional gray scale images were obtained in apical 4-chamber view,apical 2-chamber view and long axis view of left ventricle, and three levels of the short axis views(mitral valve, papillary muscle and cardiac apex). The LV wall was divided according to 18 segment model and the longitudinal,radial and circumferential systolic strain (SL, SR, SC) of each segment were analyzed. The difference between the epicardial and endocardial strain measurement were defined as strain gradient and the average of each strain component as global systolic strain. The correlation between global systolic strain of each strain component and the LV ejection fraction(LVEF) were analysed. Results Group A (coronary stenostic degree≤70%) included 176 segments, compared with control group, LS and LS gradient (LSG) decreased significantly from control group( P ＜0.05), while there was no significant difference in CS, RS and CS gradient (CSG) ( P ＞ 0.05). Group B ( coronary stenostic degree＞ 70% ) included 132 segments, compared with control group, LS, CS and RS decreased significantly in group B ( P ＜ 0.05), while there was no significantly difference in LSG and CSG( P ＞0.05). There were also significant difference in LS, RS,CS and LSG between group A and B( P ＜0.05). Global systolic strain of each strain component shown significant correlation with LVEF (P ＜ 0.0001 ). And the global longitudinal systolic strain (GLS) correlated with LVEF most tightly. Conclusions Strain parameter of VVI technique could not only accurately analyze the LV systolic dysfunction but also reflect the stenostic degree of coronary artery. GLS could be a new index for LV systolic function assessment in patients with coronary artery disease. Key words: Echocardiography; Coronary disease; Ventricular function,left; Velocity vector imaging

151 Usefulness of contrast echocardiography in Tako-Tsubo cardiomyopathy

Assessment of left ventricular (LV) dysfunction in Tako-Tsubo cardiomyopathy (TTC) is of importance. Biplane LV angiography well-characterizes this dysfunction, but is invasive. The aim of this prospective study was to assess the reliability of contract echocardiography in TTC. We prospectively studied 50 women divided into 2 groups: 25 consecutive patients with TTC (group 1) and 25 patients with proved coronary artery disease (CAD) (group 2). Groups 2 was age- and sex-matched with group 1. All patients underwent coronary arteriography, biplane LV angiography, conventional transthoracic echocardiography and contrast transthoracic echocardiography less than 24 hours after the onset of symptoms. Gold standard for LV systolic function assessment was LV angiography. Mean age of patients with TTC was 73 ± 11 years. Mean angiographic LVEF was 38 ± 9%. LV segments were well-classified as having (or not) wall motion abnormalities in 70% and 88% by observer 1 using conventional and contrast echocardiography, respectively (p < 0.0001), and in 91% and 99% by observer 2 using conventional and contrast echocardiography, respectively (p < 0.0001). In patients with TTC, LVEF was 42 ± 11% assessed by conventional echocardiography (versus 38 ± 9% by LV angiography, p < 0.0001) and 38.2 ± 8.5% using contrast agent (p = 0.42, as compared to LV angiography). Sensitivities and specificities for the diagnosis of TTC by observer 1 were respectively 55% and 64% using conventional echo versus 88% and 84% using contrast agent. Sensitivities and specificities for observer 2 were respectively 72% and 88% using conventional echo versus 96% and 96% using contrast agent. Accuracy for the diagnosis of TTC was significantly improved using contrast echocardiography for both observers, whereas agreement between both observers was excellent using contrast agent (kappa = 0.85 versus 0.34 using conventional echocardiography). We demonstrated that contrast echocardiography is an accurate imaging method for a non-invasive assessment of left ventricular systolic function in TTC.

CARDIAC CONTRACTILITY MEASURES OF LEFT VENTRICULAR SYSTOLIC FUNCTIONAL ASSESSMENT OF NORMAL AND DISEASED HEARTS

Left ventricular (LV) contraction is the basis of LV systolic function, impairment of which underlies heart failure pathophysiology. Its accurate quantification in the form of LV contractility indices is imperative for diagnostic and follow-up assessment of LV systolic function in heart failure. Herein, we analyze LV contractile performance by focusing on LV contractility indices at different physiological organizational levels: from sarcomere dynamics to LV myocardial properties (such as elastic modulus and elastance), and from LV wall contractile stress development to the generation of intra-LV blood flow velocities and pressure distributions. Further, we present the development analyses of these indices and their medical applications. Using improved development of invasive and noninvasive techniques for measuring ventricular pressure, geometry, and volume, we show how these indices have become more amenable for clinical usage to obtain better patient assessment. The purpose of this paper is to present a comprehensive coverage of LV contraction physiology, indices to qualify LV contraction, formulation, and medical applications of some major intrinsic LV contractility indices, so as to provide the basis of functional assessment of normal versus diseased hearts.

Echocardiography in the assessment of left ventricular longitudinal systolic function: current methodology and clinical applications

Quantification of left ventricular (LV) systolic function represents a major aspect of echocardiographic assessment in the spectrum of cardiac diseases. However, because of the high complexity of LV contraction mechanics, the classical approach with assessment of a single measure of systolic function, such as ejection fraction or fractional shortening, has been largely superseded. During the last years, through the considerable technical advances in the field of ultrasonography, a number of different echocardiographic methodologies have become available to perform a detailed assessment of different aspects of LV contraction. In particular, evaluation of LV longitudinal systolic dynamics has progressively gained importance as a key aspect in the assessment of LV systolic function. For most of the techniques currently used to explore LV longitudinal function, the clinical usefulness in both research and daily practice has been validated by consistent evidence and their use is rapidly increasing. Technical considerations and potential clinical applications of the assessment of LV longitudinal systolic function are reviewed.

The impact of endurance exercise training on left ventricular systolic mechanics

Although exercise training-induced changes in left ventricular (LV) structure are well characterized, adaptive functional changes are incompletely understood. Detailed echocardiographic assessment of LV systolic function was performed on 20 competitive rowers (10 males and 10 females) before and after endurance exercise training (EET; 90 days, 10.7 +/- 1.1 h/wk). Structural changes included LV dilation (end-diastolic volume = 128 +/- 25 vs. 144 +/- 28 ml, P < 0.001), right ventricular (RV) dilation (end-diastolic area = 2,850 +/- 550 vs. 3,260 +/- 530 mm2, P < 0.001), and LV hypertrophy (mass = 227 +/- 51 vs. 256 +/- 56 g, P < 0.001). Although LV ejection fraction was unchanged (62 +/- 3% vs. 60 +/- 3%, P = not significant), all direct measures of LV systolic function were altered. Peak systolic tissue velocities increased significantly (basal lateral S'Delta = 0.9 +/- 0.6 cm/s, P = 0.004; and basal septal S'Delta = 0.8 +/- 0.4 cm/s, P = 0.008). Radial strain increased similarly in all segments, whereas longitudinal strain increased with a base-to-apex gradient. In contrast, circumferential strain (CS) increased in the LV free wall but decreased in regions adjacent to the RV. Reductions in septal CS correlated strongly with changes in RV structure (DeltaRV end-diastolic area vs. DeltaLV septal CS; r2 = 0.898, P < 0.001) and function (Deltapeak RV systolic velocity vs. DeltaLV septal CS, r2 = 0.697, P < 0.001). EET leads to significant changes in LV systolic function with regional heterogeneity that may be secondary to concomitant RV adaptation. These changes are not detected by conventional measurements such as ejection fraction.

Left ventricular systolic function assessment in patients with dilated heart failure using cardiovascular magnetic resonance

Cardiovascular magnetic resonance (CMR) has become a reference standard for the measure-ment of cardiac volumes, function, and mass. This study aims to reconstruct three dimen-sional modeling of the left ventricle (LV) in pa-tients with heart failure (HF) using CMRtools and thereby derive the LV functional indices. CMR images were acquired in 41 subjects (6 females) with heart failure (HF) and 12 normal controls (4 females). Five comparisons were made (i) nor-mal and dilated heart failure subjects, (ii) male and female normal heart, (iii) male and female dilated heart, (iv) male normal and dilated heart failure and (v) female normal and dilated heart failure. In HF, a significant higher values of EDV (320 刡 79 vs. 126 刡 22 ml, P&amp;amp;amp;lt;0.0001), ESV (255 刡 68 vs. 54 刡 12 ml, P&amp;amp;amp;lt;0.00001) and lower values of EF (20 刡 7 vs. 58 刡 5 %) were found compared that of normal control. There were significant difference on LV EDV and ESV between sex in both normal and HF subjects.

Assessment of Left Ventricular Function by Echocardiography: A Technique in Evolution

One of the earliest applications of clinical echocardiography was the evaluation of left ventricular (LV) size and function. The accuracy of the determination of global and regional LV function with echocardiography has improved as the technology has matured. The following paper discusses the advances in LV function assessment starting with Inge Edler's original A-mode and M-mode observation moving through two dimensional echocardiographic methods to new three dimensional echocardiographic assessment and even new Doppler and speckle myocardial methods. During the evolution of ultrasonic assessment of LV function, each new method has overcome limitations of previous ones, resulting in better appreciation of the LV geometry and volume and improved accuracy and reproducibility for quantitation. As discussed in this report, many of the echocardiographic methods used today to assess LV systolic function were envisioned by Harvey Feigenbaum more than 25 years ago. The future will undoubtedly see a new method of clinical cardiology care but with continued evolution, echocardiographic quantitation of LV function should remain a vital part of patient care.

Atrium-driven Mitral Annulus Motion Velocity Reflects Global Left Ventricular Function and Pulmonary Congestion During Acute Biventricular Pacing

The short-term effect of acute biventricular pacing on cardiac function in patients with chronic heart failure undergoing heart surgery is widely unknown. The present study was designed to determine whether mitral annular tissue Doppler imaging (TDI) is useful to predict acute changes in global systolic function determined by the continuous cardiac output method that was measured postoperatively during various pacing configurations in patients with depressed left ventricular (LV) function. TDI peak velocities of systolic (Sm), early diastolic (Em), and late diastolic (Am) mitral annular motion waves were measured in 17 patients (age 67 +/- 8 years, 10 male) with depressed LV systolic function (LV ejection fraction < or = 35%) and QRS duration > 120 ms undergoing temporary epicardial biventricular pacing after aortocoronary bypass and valve surgery. TDI velocities, QRS duration on surface electrocardiogram, cardiac index (CI), right atrial pressure, pulmonary artery pressure, and pulmonary capillary wedge (PCW) pressure were measured simultaneously during various pacing configurations (right atrial-biventricular, right atrial-LV, right atrial-right ventricular, atrial inhibited, and no pacing). Univariate linear regression analysis showed a good correlation between Am and CI (r = 0.53, P = .0001) determined in all pacing modes, a weak correlation between Sm and CI (r = 0.31, P = .017), and no correlation between Em and CI (r = 0.21, P = .074). Am > 6 cm/s predicted a CI of 2.5 L/min/m(2) or more with a sensitivity of 95% and a specificity of 30%. All TDI values correlated negatively with PCW (r = -0.53, P = .0001 for Sm; r = -0.34, P = .01 for Em; r = -0.50, P = .0001 for Am). Am greater than 6 cm/s predicted a PCW of 16 mm Hg or less with a specificity of 100% and a sensitivity of 34%. Mean values of TDI velocities and hemodynamic parameters were not significantly different between each pacing configuration. Peak Am mitral annular velocity correlates well with CI and PCW, respectively, thus providing an easy means to assess LV systolic function and pulmonary congestion during cardiac pacing in chronic heart failure.

The Effect of High-Intensity Rowing and Combined Strength and Endurance Training on Left Ventricular Systolic Function and Morphology

Combined strength and endurance training may result in alterations in left ventricular (LV) systolic function and morphology, however, the acute effect of high-intensity rowing exercise and concurrent training-induced adaptations on LV systolic function are not well known. The purpose of this investigation was to assess LV systolic function before and after a simulated 2000-m rowing race on a Concept II rowing ergometer and evaluate these adaptations following 10 weeks of concurrent strength and endurance training. Furthermore, resting LV morphology was assessed prior to and following the 10-week training program. Ten male subjects underwent two-dimensional echocardiograms at rest, immediately following (95 +/- 27 s), as well as 5 and 45 minutes after, a simulated 2000-m rowing race. These measurements were also made before and after 10 weeks of training. Irrespective of testing time, performance of a 2000-m rowing race resulted in an increase in fractional area change (0.51 +/- 0.06 vs. 0.63 +/- 0.09; p < 0.05) due to an increase in LV contractility. Concurrent strength and endurance training resulted in an increase in the resting LV diastolic cavity area (20.64 +/- 2.59 vs. 22.82 +/- 2.17 cm (2); p < 0.05), end systolic myocardial area (23.27 +/- 4.86 vs. 24.56 +/- 4.00 cm (2); p < 0.05) and LV mass (179.07 +/- 46.91 g vs. 210.46 +/- 51.13 g; p < 0.05). These findings suggest that the acute increase in LV systolic function following a simulated 2000-m rowing race was due to heightened LV contractile reserve. Further, 10 weeks of combined strength and endurance training resulted in an increase in resting LV diastolic cavity size, wall thickness and mass.

Socioeconomic status, treatment, and outcomes among elderly patients hospitalized with heart failure: Findings from the National Heart Failure Project

Prior studies have reported conflicting findings concerning the association of socioeconomic status (SES), treatment, and outcomes in patients hospitalized with heart failure (HF). We conducted a retrospective analysis of medical record data from a national sample of Medicare beneficiaries hospitalized with HF between March 1998 and April 1999 (n = 25,086) to assess the association of patient SES, treatment, and outcomes. Patients' SES was designated as lower, lower-middle, higher-middle, and higher using residential ZIP code characteristics. Patients were evaluated for left ventricular systolic function assessment, prescription of angiotensin-converting enzyme inhibitors at discharge, readmission within 1 year of discharge, and mortality within 30 days and 1 year of admission. Hierarchical logistic regression models were used to assess the association of SES, quality of care, and outcomes adjusting for patient, physician, and hospital characteristics. Lower SES patients (relative risk [RR] 0.92, 95% CI 0.87-0.96) were modestly less likely to have had a left ventricular systolic function assessment, but had a similar adjusted likelihood of being prescribed angiotensin-converting enzyme inhibitors (RR 1.03, 95% CI 0.93-1.11) compared with higher SES patients after multivariable adjustment. Socioeconomic status was not associated with 30-day mortality after multivariable adjustment, but lower SES patients had a higher risk of 1-year mortality (RR 1.10, 95% CI 1.02-1.19) and readmission within 1 year of discharge (RR 1.08, 95% CI 1.03-1.12) compared with higher SES patients. Socioeconomic status in patients hospitalized with HF was not strongly associated with quality of care or 30-day mortality. However, the increased risk of 1-year mortality and readmission among patients of lower SES suggest SES may influence outcomes after hospitalization for HF.

Left Ventricular Chamber and Myocardial Systolic Function Reserve in Patients with Type 1 Diabetes Mellitus: Insight from Traditional and Doppler Tissue Imaging Echocardiography

We sought to evaluate in patients with type 1 diabetes mellitus (DM1): (1) whether myocardial afterload correlates with left ventricular (LV) circumferential and longitudinal systolic function at rest and during low-dose dobutamine (LDD) infusion, and whether longitudinal and circumferential LV systolic function reserves are correlated; and (2) to explore relations between LV systolic mechanics and LV chamber output reserves. A total of 20 patients with DM1 underwent echocardiography to assess LV systolic function at rest and at peak LDD (7.5 microg/kg/min). At rest, echocardiographic data of patients with DM1 were compared with those from 24 healthy control subjects. LV afterload was estimated by computing circumferential end-systolic stress (ESS). LV chamber systolic function was assessed by computing ejection fraction and ESS/end-systolic volume index; LV circumferential myocardial contractility was explored by computing midwall fractional shortening (MWS) and ESS-corrected MWS. Longitudinal LV systolic function was assessed using color Doppler tissue (DTI) to assess peak systolic velocities and maximal displacement of the lateral and medial mitral annulus in apical 4-chamber view; regional deformation analyses were computed at the midportion of the posterior interventricular septum (peak strain and peak strain rate); strain/ESS was assessed as an alternative indicator of longitudinal myocardial contractility. LV chamber output was assessed by computing stroke index. DM1 and control groups did not differ in terms of sex distribution, mean age, blood pressure, LV mass index and geometry, and at-rest parameters of LV systolic function (all P > .1), whereas body mass index was higher and systolic lateral mitral annulus velocity was lower in the DM1 than control group (both P < .01). At rest, in both groups, higher ESS correlated with lower ejection fraction and lower MWS; ESS did not show significant correlation with longitudinal systolic function parameters. At peak LDD in DM1, heart rate changed minimally; ESS decreased significantly (P < .01); circumferential and longitudinal LV systolic functions increased significantly but did not show intercorrelation; higher ESS correlated with lower ejection fraction; longitudinal LV systolic function parameters did not show correlation with ESS. In a multivariate analysis, percent increase in stroke index correlated with percent change of MWS (beta = 0.74, P < .01), and to a lesser extent with the percent increase of systolic lateral mitral annulus velocity (beta = 0.47, P = .04), independent to age, sex, percent change of ESS, and heart rate. LV longitudinal systolic function (DTI) parameters did not fall into the paradigm of the stress-shortening relationship used to describe LV contractility. However, both LV circumferential contractility and longitudinal systolic function reserves correlated with stroke index reserve during LDD.

Traditional and Color M-Mode Parameters of Left Ventricular Diastolic Function During Low-dose Dobutamine Stress Echocardiography: Relations to Contractility Reserve

Cross-sectional studies reported that left ventricular (LV) systolic and diastolic functions are correlated. However, whether changes in wall-motion score index (WMSI) or 2-dimensional ejection fraction (EF) predict changes of Doppler parameters of LV diastolic function is unclear. Patients with known or suspected history of coronary artery disease underwent assessment of LV systolic function (WMSI, EF) and diastolic function at baseline and during stress echocardiography by low-dose dobutamine (LDD) (peak infusion 10 microg/kg/min). Peak velocities of early (E) and late (A) LV filling waves and E wave deceleration time were measured according to standard protocol. E wave propagation rate (EVp) was assessed by color Doppler M-mode across the mitral valve. Tei index was calculated as: (A wave to E wave time - ejection time)/ejection time. Changes at LDD were calculated as: 100 x (value at LDD - value at baseline)/baseline. The study group comprised 66 patients, mean age 61 +/- 10 years, 80% men. Worse LV systolic function was associated with more severely impaired LV diastolic function both at baseline and at LDD. However, percent change of WMSI and change in EF did not correlate with percent change of EVp and E/E wave propagation rate, but with percent change of Tei index. At LDD, patients with myocardial viability did not show greater percent change of LV diastolic function parameters but significantly lower Tei index. In patients with suspected or known coronary artery disease, assessment of diastolic function reserve by LDD stress echocardiography using traditional and color M-mode Doppler may add quantitative information on myocardial function beyond traditional assessment of contractility reserve by WMSI or EF.

Using Impedance Cardiography to Assess Left Ventricular Systolic Function via Postural Change in Patients With Heart Failure

For the diagnosis and management of heart failure, it would be useful to have a simple point-of-care test for assessing ventricular function that could be performed by a nurse. An impedance cardiography (ICG) parameter called systolic amplitude (SA) can serve as an indicator of left ventricular systolic function (LVSF). This study tested the hypothesis that patients with normal LVSF should have a significant increase in SA in response to an increase in end-diastolic volume caused by postural change from sitting upright to supine, while patients with depressed LVSF associated with heart failure should have a minimal increase or a decrease in SA from upright to supine. ICG data were obtained in 12 patients without heart disease and with normal LVSF and 18 patients with clinically diagnosed heart failure. Consistent with the hypothesis, patients with normal LVSF had a significant increase in SA from upright to supine, whereas heart failure patients had a minimal increase or a decrease in SA from upright to supine. This ICG procedure may be useful for monitoring the trend of patient response to titration of beta blockers and other medications. ICG potentially could be used to detect worsening LVSF and provide a means of measurement for adjusting treatment.

Cardiac troponin T as an indicator of reduced left ventricular contractility in experimental anthracycline-induced cardiomyopathy.

Cardiac troponin T (cTnT) plasma concentration is considered a useful marker of anthracycline-induced cardiomyopathy. In this study we used daunorubicin-treated Chinchilla rabbits as a model to investigate the relationship between left ventricular contractility and cTnT plasma concentrations. Two groups of animals were used: a control group (n=8) received i.v. saline, and an experimental group (n=11) received daunorubicin (3 mg/kg, i.v.). The substances were administered once weekly for 10 weeks, and 5-7 days after the last administration, left ventricular cardiac contractility (dP/dtmax) was invasively measured as a contractility index and blood was sampled for cTnT concentration determination (Elecsys Troponin T STAT immunoassay). Cardiac contractility was significantly lower in seven surviving daunorubicin-treated animals than in control animals (745.7+/-69.3 vs 1393.4+/-25.5 kPa/s; P<0.001), while cTnT plasma concentrations were significantly increased (medians 0.278 vs 0.000 ng/ml; P<0.001). When the dP/dtmax values of individual daunorubicin-treated animals were plotted against the corresponding cTnT plasma concentrations, a close negative linear correlation was found (R=-0.910; P<0.005; regression equation: dP/dtmax=-1861*cTnT+1234). This study suggests that determination of cTnT plasma levels, which is simple and inexpensive, could be used in anthracycline-treated patients for left ventricular systolic function assessment and contractility estimation.

A hand-carried personal ultrasound device for rapid evaluation of left ventricular function: use after limited echo training.

A hand-carried personal ultrasound device (HCPUD) may be used for rapid cardiac screening by physicians with limited echo training. Our objective was to determine the accuracy of rapid HCPUD evaluation of left ventricular (LV) size and function when used by a Cardiology Fellow. Forty-five patients underwent an HCPUD exam using a 2.4-kg device with a 2- to 4-MHz curved transducer and color power Doppler (SonoSite). The results were compared with sonographer-performed and echocardiographer-interpreted exams using conventional equipment. The HCPUD exam lasted 6 +/- 2 minutes. There was 100% agreement between HCPUD and conventional echo on qualitative assessment of LV systolic function. Comparing the HCPUD and conventional linear measurements of left ventricular end-diastolic dimension (LVEDD) and of interventricular septal (IVS) thickness: LVEDD is HCPUD = 0.94 conventional -0.2,r = 0.82, P < 0.0001; IVS is HCPUD= 0.59 conventional+0.6, r = 0.69, P < 0.0001. Thus, an HCPUD can effectively be used after limited training to rapidly screen for qualitative abnormalities of LV systolic function. Quantitative measurements of smaller structures with the HCPUD are more challenging.

10.45 Comparison of ECG gated myocardial SPECT with thallium-201 and Doppler issue echocardiography in the assessment of left-ventricular systolic function

10.45 Comparison of ECG gated myocardial SPECT with thallium-201 and Doppler issue echocardiography in the assessment of left-ventricular systolic function