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Isovolumic Relaxation Time (isovolumic + relaxation_time)
Selected AbstractsAcute Adaptation to Volume Unloading of the Functional Single Ventricle in Children Undergoing Bidirectional Glenn AnastomosisCONGENITAL HEART DISEASE, Issue 2 2009Catherine Ikemba MD ABSTRACT Objective., Volume unloading of the functional single ventricle after a bidirectional Glenn anastomosis (BDG) prior to 1 year of age leads to improved global ventricular function as measured by the myocardial performance index (MPI), a Doppler-derived measurement of combined systolic and diastolic ventricular function. Systolic function remains unchanged after BDG according to previous studies; however, acute changes in global and diastolic function have not been previously investigated in this cohort. Our objective was to assess the short-term effects of the BDG on global ventricular function in patients with a functional single ventricle. Design., Echocardiograms to obtain MPI, isovolumic contraction time, and isovolumic relaxation time were performed at four time periods: in the operating room, in the operating room prior to BDG, shortly after separation from cardiopulmonary bypass, less than 24 hours postoperatively, and either prior to hospital discharge or at the first clinic follow-up visit. Results., Twenty-six patients were enrolled. There was significant ventricular dysfunction noted shortly after separation from cardiopulmonary bypass, median MPI 0.63 (0.39,0.81), that persisted in the short term postoperatively median MPI 0.50 (0.40,0.63). Isovolumic contraction time did not change, however, isovolumic relaxation time was significantly prolonged following BDG. Conclusion., In the postoperative patient after BDG, systolic function is preserved; however, there is evidence of diastolic and global ventricular dysfunction, at least in the short term. [source] The Myocardial Performance Index in Patients with Aortic StenosisECHOCARDIOGRAPHY, Issue 4 2002Jude A. Mugerwa M.D. Objectives: This study was designed to determine the effect of chronic afterload on a Doppler-derived myocardial performance index (MPI) combining both systolic and diastolic left ventricular dysfunction. Methods: The study included 36 patients with a diagnosis of aortic stenosis and 36 normal subjects. Doppler-derived myocardial performance index (MPI), defined as the sum of the isovolumic contraction time and isovolumic relaxation time divided by ejection time, was measured from the mitral valve inflow and left ventricular outflow velocity patterns and was then related to the aortic valve area, valve gradient, and other echocardiographic variables. Results: The values of the Doppler-derived MPI in the patients with aortic stenosis were significantly higher than those in the controls (0.54 ± 0.20 vs 0.38 ± 0.04, respectively; P < 0.001). Transmitral deceleration time and the E/A ratio (r = 0.47 and r = 0.35, respectively; P < 0.05) were significant univariate correlates, and mitral deceleration time was the only significant correlate of MPI. However the index did not correlate with aortic valve area, peak and mean valve gradients, left ventricular mass, or age. Conclusions: Doppler-derived MPI reflects severity of global left ventricular dysfunction in patients with aortic stenosis and may be of clinical value in this patient population. [source] Tissue inhibitor of metalloproteinse-1 is a marker of diastolic dysfunction using tissue doppler in patients with type 2 diabetes and hypertensionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2005M. H. Tayebjee Abstract Background, Tissue inhibitor of metalloproteinase-1 (TIMP-1) is associated with increased fibrosis of the extracellular matrix (ECM). Myocardial stiffness is a feature of diastolic dysfunction. We assessed circulating TIMP-1 as a marker of diastolic dysfunction in patients with type 2 diabetes mellitus (DM) and hypertension, who were compared with healthy controls. Methods, We recruited 54 patients (43 males; mean age 68 ± 5 years) with treated type 2 DM (i.e. controlled glycaemia, hypertension, hyperlipidaemia), 35 (30 males; 69 ± 8 years) treated nondiabetic hypertensives, and 31 healthy controls (18 males; 66 ± 5 years). Circulating TIMP-1 was measured by ELISA. Using transthoracic echocardiography, the early (E) diastolic mitral inflow velocity was measured with pulse wave Doppler, and the early mitral annular velocity (e,), a recognized index of diastolic relaxation, was measured with tissue Doppler. The E/A ratio was also calculated and isovolumic relaxation time measured. Results, Mean e, levels differed significantly between controls, diabetics and hypertensives (P < 0·0001). Circulating TIMP-1 was significantly different between patients and controls (P = 0·006), but there was no statistically significant difference between the DM and hypertension group. In both groups, only e, was negatively correlated with TIMP-1 levels, with a stronger correlation among the hypertensive patients (Spearman r = ,0·544, P = 0·001) when compared with the diabetic group (r = ,0·341, P = 0·011). Conclusion, Diastolic relaxation is impaired in diabetes and hypertensive patients. The relationship between TIMP-1 and e, may reflect increased myocardial fibrosis and consequent diastolic dysfunction, which may be more prominent in hypertension. [source] High temporal resolution SSFP cine MRI for estimation of left ventricular diastolic parametersJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 4 2010Ramkumar Krishnamurthy MS Abstract Purpose: To obtain high temporal resolution (HTR) magnetic resonance (MR) steady-state free-precession (SSFP) cine cardiac images by using multichannel radiofrequency (RF) hardware and parallel imaging techniques; to study the effect of temporal resolution; and to compare the derived left ventricular (LV) diastolic filling parameters with echocardiographic results. Materials and Methods: HTR images were acquired in 13 healthy volunteers using a 1.5 T scanner with 32 RF channels and sensitivity encoding (SENSE) and k-t broad-use linear-acquisition speedup technique (k-t BLAST) imaging techniques. LV diastolic parameters were calculated and compared to conventional echocardiographic indices such as the isovolumic relaxation time (IVRT) and E/A ratio. The need for HTR was assessed and the MR results were compared with echocardiographic results. Results: The HTR (,6-ms) images yielded higher peak filling rates, peak ejection rates, and peak atrial filling rates. A progressive decline in filling and ejection rates was observed with worsening temporal resolution. The IVRTs and E/A ratios measured with MR versus echocardiography were in broad agreement. Also, SENSE and k-t BLAST yielded similar diastolic functional parameters. Conclusion: With SENSE or k-t BLAST and modern hardware, HTR cine images can be obtained. The lower temporal resolutions (30,50 ms) used in clinical practice reduce LV filling rates by ,30% and may hinder characterization of transient phenomena such as the IVRT. J. Magn. Reson. Imaging 2010;31:872,880. ©2010 Wiley-Liss, Inc. [source] Estimation of Left Ventricular Filling Pressure by Doppler Echocardiography in Dogs with Pacing-Induced Heart FailureJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2008K.E. Schober Background: Congestive heart failure (CHF) is a common clinical syndrome characterized by elevated filling pressure. Hypothesis: Doppler echocardiographic (DE) variables of left ventricular (LV) filling can predict a decline of LV end-diastolic pressure (LVEDP) induced by acute preload reduction in dogs with compensated CHF. Animals: Five male hound dogs. Methods: Dogs previously instrumented with a transvenous cardiac pacemaker and a LV pressure gauge were paced at 160,180 bpm to induce mild CHF characterized by LVEDP > 20 mmHg. LVEDP and 9 DE variables of LV filling derived from diastolic time intervals, transmitral and pulmonary venous flow, and tissue Doppler imaging were measured simultaneously at baseline and 30, 60, 120, and 240 minutes after furosemide (4 mg/kg, IV) or placebo (0.9% saline, IV). Repeated measures analysis of variance and correlation analysis were used to determine the association between the decline of LVEDP after furosemide and DE measures of LV filling pressure (LVFP). Results: Furosemide but not placebo decreased LVEDP (P < .001). The ratio of early transmitral flow velocity to LV isovolumic relaxation time (E : IVRT) predicted LVEDP best (R2= .50; P < .001). Correlations were also found between LVEDP and IVRT, E, ratio between E and late diastolic transmitral flow velocity (E : A), and early diastolic velocity of the mitral annulus (Ea). The ratio of E to Ea (E : Ea) was not useful in the prediction of LVEDP in this model. Conclusion and Clinical Importance: E : IVRT can be used to predict LVFP in dogs with mild left-sided CHF induced by rapid pacing. [source] Assessment of Diastolic Function by Doppler Echocardiography in Normal Doberman Pinschers and Doberman Pinschers with Dilated CardiomyopathyJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2007M. Lynne O'Sullivan Background: Assessment of diastolic function in patients with dilated cardiomyopathy (DCM) has the potential to add valuable information regarding hemodynamics, disease severity, and prognosis. The purpose of this study was to determine transmitral flow (TMF), isovolumic relaxation time (IVRT), pulmonary venous flow (PVF), flow propagation velocity (Vp), and mitral annular velocities by tissue Doppler in Doberman Pinschers with and without DCM. Hypothesis: It was anticipated that normal and DCM Dobermans would differ with respect to these parameters, and that associations with time to congestive heart failure (CHF) or death would be found. Animals: Thirty client-owned Doberman Pinschers (10 each of normal, occult DCM, and overt DCM) were studied. Methods: Each dog underwent echocardiography with or without thoracic radiography (to confirm CHF) for classification as normal or DCM-affected, followed by collection of echocardiographic diastolic parameters. Results: The group with occult DCM exhibited features of pseudonormal TMF, reduced systolic to diastolic PVF ratio, and reduced Vp. Shorter early TMF deceleration time (DTE) was associated with shorter time to CHF or sudden death. The group with overt DCM exhibited restrictive TMF, blunted systolic PVF, and reduced early and late diastolic mitral annular velocities. Conclusions and Clinical Importance: Doberman Pinschers showed evidence of moderate and severe diastolic dysfunction in occult and overt DCM, respectively. Short DTE may be a useful predictor of onset of CHF or sudden death. [source] Effect of Right Ventricular Apex Pacing on the Tei Index and Brain Natriuretic Peptide in Patients with a Dual-Chamber PacemakerPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2006HITOSHI ICHIKI Background: Asynchronous electrical activation induced by right ventricular apex (RVA) pacing can cause various abnormalities in left ventricular (LV) function, particularly in the context of severe LV dysfunction or structural heart disease. However, the effect of RVA pacing in patients with normal LV and right ventricular (RV) function has not been fully elucidated. The aim of this study was to characterize the effects of RVA pacing on LV and RV function by assessing isovolumic contraction time and isovolumic relaxation time divided by ejection time (Tei index) and by assessing changes in plasma brain natriuretic peptide (BNP). Methods: Doppler echocardiographic study and BNP measurements were performed at follow-up (mean intervals from pacemaker implantation, 44 ± 75 months) in 76 patients with dual chamber pacemakers (sick sinus syndrome, n = 30; atrioventricular block, n = 46) without structural heart disease. Patients were classified based on frequency of RVA pacing, as determined by 24-hour ambulatory electrocardiogram (ECG) that was recorded just before echocardiographic study: pacing group, n = 46 patients with RVA pacing ,50% of the time, percentage of ventricular paced 100 ± 2%; sensing group, n = 30, patients with RVA pacing <50% of the time, percentage of ventricular paced 3 ± 6%. Results: There was no significant difference in mean heart rate derived from 24-hour ambulatory ECG recordings when comparing the two groups (66 ± 11 bpm vs 69 ± 8 bpm). LV Tei index was significantly higher in pacing group than in sensing group (0.67 ± 0.17 vs 0.45 ± 0.09, P < 0.0001), and the RV Tei index was significantly higher in pacing group than in sensing group (0.34 ± 0.19 vs 0.25 ± 0.09, P = 0.011). Furthermore, BNP levels were significantly higher in pacing group than in sensing group (40 ± 47 pg/mL vs 18 ± 11 pg/mL, P = 0.017). With the exception of LV diastolic dimension (49 ± 5 mm vs 45 ± 5 mm, P = 0.012), there were no significant differences in other echocardiographic parameters, including left atrium (LA) diameter (35 ± 8 mm vs 34 ±5 mm), LA volume (51 ± 27 cm3 vs 40 ± 21 cm3), LV systolic dimension (30 ± 6 mm vs 29 ± 7 mm), or ejection fraction (66 ± 9% vs 63 ± 11%), when comparing the two groups. Conclusions: These findings suggest that the increase of LV and RV Tei index, LVDd, and BNP are highly correlated with the frequency of the RVA pacing in patients with dual chamber pacemakers. [source] Levosimendan versus Dobutamine in Heart Failure Patients Treated Chronically with CarvedilolCARDIOVASCULAR THERAPEUTICS, Issue 3 2008Hamza Duygu Introduction: Although beta-blockers are highly effective in the treatment of heart failure (HF), many patients with HF receiving a beta-blocker continue to become decompensated and require hospitalization for worsening HF. Levosimendan and dobutamine are used to manage decompensated HF, but their comparative effects on left ventricular (LV) function in patients prescribed beta-blockers are unknown. Aims: The aim of this study was to compare the effects of dobutamine and levosimendan on LV systolic and diastolic functions in chronic HF patients treated chronically with carvedilol. Forty patients with chronic HF who had NYHA class III to IV symptoms, a LV ejection fraction (LVEF) <40%, and ongoing treatment with carvedilol were enrolled in this randomized (1:1), dobutamine controlled, open-label study. Before and 24 h after treatment, LVEF, mitral inflow peak E and A wave velocity, E/A ratio, the deceleration time of the E wave (DT), isovolumic relaxation time (IVRT), peak systolic (Sm) and early diastolic (Em) mitral annular velocity, and systolic pulmonary artery pressure (SPAP) were measured by echocardiography. Results: Levosimendan produced a statistically significant increase in LVEF (28 ± 5% vs. 33 ± 3%), Sm (6.5 ± 1.2 cm/s vs. 7.4 ± 0.9 cm/s), DT (120 ± 10 ms vs. 140 ± 15 ms), and Em (7.5 ± 0.4 cm/s vs. 8.1 ± 0.5 cm/s) and significant decrease in E/A ratio (2.1 ± 0.3 vs. 1.7 ± 0.4) and SPAP (55 ± 5 mmHg vs. 40 ± 7 mmHg). No significant change occurred in LV systolic and diastolic function parameters, or SPAP with dobutamine treatment. Levosimendan did not significantly alter the heart rate (72 ± 4 bpm vs. 70 ± 3 bpm), systolic (105 ± 5 mmHg vs. 102 ± 4 mmHg), or diastolic blood pressure (85 ± 5 mmHg vs. 83 ± 5 mmHg) whereas with dobutamine treatment, all these parameters significantly increased. Conclusions: Dobutamine and levosimendan have different effects on LV functions in patients treated chronically with carvedilol. These differences should be considered when selecting inotropic therapy for decompensated HF receiving long-term carvedilol. [source] Evaluation of Biventricular Functions With Tissue Doppler Imaging in Patients With Myotonic DystrophyCLINICAL CARDIOLOGY, Issue 3 2010Tolga Ozyigit MD Background: Myotonic dystrophy (MD) is characterized by myotonia with dystrophic involvement of the muscles. Cardiac involvement is usually not evident in the early stages of MD. Hypothesis: We investigated biventricular functions by tissue Doppler imaging (TDI) in MD patients with no overt cardiac involvement to explore the value of TDI in the early detection of myocardial dysfunction. Methods: A total of 21 MD patients (15 male, age: 32.2 ± 12.3 yrs) and 21 healthy controls (13 male, age: 32.2 ± 7.8 yrs) were included. In addition to conventional echocardiography, pulsed Doppler and TDI were performed including measurement of myocardial performance index (MPI); peak systolic (Sm) and early (Em) and atrial (Am) diastolic myocardial velocities at the basal mitral and tricuspid annulus. Results: All patients and controls had normal ejection fraction. Transmitral E peak velocity was significantly lower while both deceleration time of E velocity and isovolumic relaxation time were significantly longer in MD patients (P = 0.007, P = 0.001, and P < 0.001, respectively). Sm, Em and Am peak velocities were significantly lower in MD patients in all segments except for Em of the mitral anterior annulus and Am of the tricuspid lateral annulus. Both left and right ventricular MPI were significantly higher in MD patients (P < 0.001 and P = 0.013, respectively). Conclusion: There are changes in myocardial systolic and diastolic functions in MD patients although they have no overt heart failure. Myocardial tissue velocities and MPI are useful in identifying subclinical biventricular involvement in these patients. Copyright © 2010 Wiley Periodicals, Inc. [source] Right ventricular myocardial isovolumic relaxation time and pulmonary pressureCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 1 2006Pulsed Doppler tissue imaging in resurrection of Burstin's nomogram Summary Aims:, Non-invasive assessment of pulmonary artery systolic pressure (PASP) has several limitations. As previously described by Burstin, the right ventricular (RV) isovolumic relaxation time (IVRt) is sensitive to changes in PASP. We therefore compared RV myocardial IVRt, derived by Doppler tissue imaging (DTI), with simultaneously measured invasive PASP. Methods and results:, Twenty-six consecutive patients (18 males, mean age 52 ± 12 years, range 23,75) underwent a simultaneous Doppler echocardiography, including DTI, and cardiac catheterization examination for measurement of PASP and right atrial mean pressures. IVRt was measured using the myocardial velocities by pulsed DTI at both basal and mid cavity segments of the RV free wall. As diastolic time intervals are influenced by heart rate IVRt was corrected for heart rate (IVRt/RR%). A significant correlation was found between PASP and regional IVRt/RR% at both the basal (r = 0·42, P<0·05) and mid cavity segment (r = 0·71, P<0·001). Furthermore, when only patients with normal right atrial pressures (<7 mmHg) were taken into account, the correlation coefficient improved at both basal and mid cavity segments (r = 0·74, P<0·05 and r = 0·83, P<0·01). Conclusion:, Pulsed Doppler-derived IVRt correlates well with PASP. The use of pulsed DTI for measurement of IVRt is simple, reproducible and easy to obtain. We propose this method as an additional non-invasive tool in the assessment of PASP. [source] Cardiac dysfunction during exercise in patients with primary hyperparathyroidismBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2000I.-L. Nilsson Background ,Non-traditional' manifestations of primary hyperparathyroidism (HPT) are controversial, and include morbidity, mortality and risk factors for cardiovascular diseases with some prospects of normalization by parathyroidectomy (PTX). This study evaluated previously unexplored data on cardiac function during exercise in HPT. Methods Thirty patients with HPT (mean(s.d.) serum calcium 2·96(0·24) mmol l,1) and 30 normocalcaemic controls (selected randomly from the background population, and matched for age and sex) underwent exercise testing, echocardiography and 24-h ambulatory blood pressure recordings before and a mean of 13 months after PTX. Results HPT was associated with higher systolic blood pressure during exercise (mean(s.d.) 223(28) versus 203(33) mmHg; P = 0·02), which correlated to the left ventricular (LV) mass and serum PTH (P = 0·014, P = 0·004); higher LV mass in men (mean(s.d.) 142(20) versus 113(28) g m,2), which might relate to the hypertrophic effect of PTH; and increased LV isovolumic relaxation times (mean(s.d.) 102(19) versus 91(15) ms; P = 0·018), indicating LV diastolic dysfunction. ST depression during exercise decreased significantly (mean(s.d.) , 1·0(0·9) versus 0·7(0·5) mm; P = 0·028) and LV mass declined in proportion with the time after PTX (P = 0·04 in men). PTX also affected systolic functions, as fractional shortening, atrioventricular plane displacement and systolic index decreased in men (P = 0·05, P = 0·04, P = 0·04). Twenty-four-hour blood pressures were higher in HPT (P = 0·008), when subjects on ,-blockers (seven patients, five controls) were excluded, and were unaltered by PTX. Conclusion LV systolic and diastolic dysfunction occurs in HPT. The diastolic dysfunction seems to diminish with time after PTX, while the positive inotropic effect of calcium in itself may alleviate the systolic dysfunction. © 2000 British Journal of Surgery Society Ltd [source] | ||||||||||