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Myocardial Performance (myocardial + performance)

Distribution by Scientific Domains

Medical Sciences	84%

Terms modified by Myocardial Performance

myocardial performance index

Selected Abstracts

Evaluation of Myocardial Performance with Conventional Single-Site Ventricular Pacing and Biventricular Pacing in a Canine Model of Atrioventricular Block

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2003
PATRICIO A. FRIAS M.D.
Introduction: The aim of this study was to evaluate epicardial biventricular pacing as a means of maintaining synchronous ventricular activation in an acute canine model of AV block with normal ventricular anatomy and function. Chronic single-site ventricular pacing results in dyssynchronous ventricular activation and may contribute to ventricular dysfunction. Biventricular pacing has been used successfully in adult patients with congestive heart failure. Methods and Results: This was an acute study of open chest mongrel dogs (n = 13). ECG, left ventricular (LV), aortic, and pulmonary arterial pressures were measured. LV impedance catheters were used to assess cardiodynamics using instantaneous LV pressure-volume relations (PVR). Following radiofrequency ablation of the AV node, a temporary pacemaker was programmed 10 beats/min above the intrinsic atrial rate, with an AV interval similar to the baseline intrinsic PR interval. The pacing protocol consisted of 5-minute intervals with the following lead configurations: right atrium-right ventricular apex (RA-RVA), RA-LV apex (LVA), and RA-biventricular using combinations of four ventricular sites (RVA, RV outflow tract [RVOT], LVA, LV base [LVB]). RA-RVA was used as the experimental control. LV systolic mechanics, as measured by the slope of the end-systolic (Ees) PVR (ESPVR, mmHg/cc), was statistically greater (P < 0.05) with all modes of biventricular pacing (RA-RVA/LVA 20.0 ± 2.9, RA-RVA/LVB 18.4 ± 2.9, RA-RVOT/LVA 15.1 ± 1.8, RA-RVOT/LVB 17.6 ± 2.9) compared to single-site ventricular pacing (RA-RVA 12.8 ± 1.6). Concurrent with this improvement in myocardial performance was a shortening of the QRS duration (RA-RVA 97.7 ± 2.9 vs RA-RVA/LVA 75.7 ± 4.9, RA-RVA/LVB 70.3 ± 4.9, RA-RVOT/LVA 65.3 ± 4.4, and RA-RVOT/LVB 76.7 ± 5.9, P < 0.05). Conclusion: In this acute canine model of AV block, QRS duration shortened and LV performance improved with epicardial biventricular pacing compared to standard single-site ventricular pacing. (J Cardiovasc Electrophysiol, Vol. 14, pp. 996-1000, September 2003) [source]

Effect of combined supplementation with vitamin E and alpha-lipoic acid on myocardial performance during in vivo ischaemia-reperfusion

ACTA PHYSIOLOGICA, Issue 4 2000
Coombes
Reactive oxygen species (ROS) contribute significantly to myocardial ischaemia-reperfusion (I-R) injury. Recently the combination of the antioxidants vitamin E (VE) and alpha-lipoic acid (, -LA) has been reported to improve cardiac performance and reduce myocardial lipid peroxidation during in vitro I-R. The purpose of these experiments was to investigate the effects of VE and , -LA supplementation on cardiac performance, incidence of dysrhythmias and biochemical alterations during an in vivo myocardial I-R insult. Female Sprague,Dawley rats (4-months old) were assigned to one of the two dietary treatments: (1) control diet (CON) or (2) VE and , -LA supplementation (ANTIOXID). The CON diet was prepared to meet AIN-93M standards, which contains 75 IU VE kg,1 diet. The ANTIOXID diet contained 10 000 IU VE kg,1 diet and 1.65 g , -LA kg,1 diet. After the 14-week feeding period, significant differences (P < 0.05) existed in mean myocardial VE levels between dietary groups. Animals in each experimental group were subjected to an in vivo I-R protocol which included 25 min of left anterior coronary artery occlusion followed by 10 min of reperfusion. No group differences (P > 0.05) existed in cardiac performance (e.g. peak arterial pressure or ventricular work) or the incidence of ventricular dysrhythmias during the I-R protocol. Following I-R, two markers of lipid peroxidation were lower (P < 0.05) in the ANTIOXID animals compared with CON. These data indicate that dietary supplementation of the antioxidants, VE and , -LA do not influence cardiac performance or the incidence of dysrhythmias but do decrease lipid peroxidation during in vivo I-R in young adult rats. [source]

Effects of Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy on Doppler Tei Index: A Midterm Follow-Up

ECHOCARDIOGRAPHY, Issue 2 2005
F.E.S.C., Josef Veselka M.D., Ph.D.
Alcohol septal ablation (PTSMA) improves outflow gradient, left ventricular (LV) diastolic function, and symptoms in patients with hypertrophic obstructive cardiomyopathy (HOCM). Tei index (TI) is a Doppler parameter reflecting both systolic and diastolic LV function. Midterm changes of TI after PTSMA have not been determined up to now. Twenty-seven consecutive patients (mean age 53 ± 13 years) with symptomatic HOCM underwent PTSMA procedure. Clinical and echocardiographic data were collected at baseline, 6 and 12 months after PTSMA. TI decreased from 0.67 ± 0.11 to 0.55 ± 0.06, isovolumic contractile time (ICT) decreased from 74 ± 20 to 48 ± 11 ms, isovolumic relaxation time decreased from 146 ± 25 to 117 ± 9 ms, and LV ejection time decreased from 330 ± 42 to 298 ± 13 ms. LV remodeling was determined by LV dimension increase from 46 ± 6 to 48 ± 6 mm and basal septum thickness reduction from 22 ± 4 to 15 ± 3 mm. LV ejection fraction decreased from 78 ± 7 to 73 ± 6% and maximal outflow gradient decreased from 69 ± 44 to 15 ± 11 mmHg. All changes were statistically significant (P < 0.01). Symptomatic improvement was characterized by relief of dyspnea (2.5 ± 0.7 versus 1.4 ± 0.6 NYHA class; P < 0.01) and angina pectoris (2.6 ± 0.9 versus 0.7 ± 0.7 CCS class; P < 0.01). PTSMA is an effective method of therapy for HOCM. Shortening of TI suggests the improvement of LV myocardial performance in the midterm follow-up. [source]

Impaired aortic elastic properties in patients with systemic sarcoidosis

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2008
I. Moyssakis
Abstract Background, Systemic sarcoidosis (Sar) is a granulomatous disorder involving multiple organs. Widespread vascular involvement and microangiopathy are common in patients with Sar. In addition, subclinical cardiac involvement is increasingly recognized in patients with Sar. However, data on the effect of Sar on the elastic properties of the arteries and myocardial performance are limited. In this study we looked for differences in aortic distensibility (AoD) which is an index of aortic elasticity, and myocardial performance of the ventricles, between patients with Sar and healthy subjects. In addition, we examined potential associations between AoD and clinical, respiratory and echocardiographic findings in patients with Sar. Materials and methods, A total of 83 consecutive patients (26 male/57 female, mean age 51·1 ± 13·3 years) with Sar, without cardiac symptoms, were included. All patients underwent echocardiographic and respiratory evaluation including lung function tests. Additionally, 83 age- and sex-matched healthy subjects served as controls. AoD was determined non-invasively by ultrasonography. Results, AoD was lower in the Sar compared to the control group (2·29 ± 0·26 vs. 2·45 ± 0·20 ·10,6 cm2· dyn,1, P < 0·01), while left ventricular mass (LVM) was higher in the Sar group (221·3 ± 50·2 vs. 195·6 ± 31·3 g, P = 0·007). Furthermore, myocardial performance of both ventricles was impaired in the Sar group. Multivariate linear regression analysis in the total sample population demonstrated a significant and independent inverse relationship between AoD and the presence of Sar (P < 0·001). The same analysis in the Sar patients showed that AoD was associated significantly and independently with the stage of Sar, age, systolic blood pressure, LVM and myocardial performance of both ventricles. No significant relationship was found between AoD and disease duration, pulmonary artery pressure or lung function tests. Conclusions, Presence and severity of Sar are associated with reduced aortic distensibility, irrespective of the disease duration, pulmonary artery pressure and lung function. In addition, patients with Sar have increased LVM and impaired myocardial performance. [source]

Evaluation of Myocardial Performance with Conventional Single-Site Ventricular Pacing and Biventricular Pacing in a Canine Model of Atrioventricular Block

Xanthine oxidase inhibitor allopurinol attenuates the development of diabetic cardiomyopathy

JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8b 2009
Mohanraj Rajesh
Abstract In this study, we investigated the effect of the xanthine oxidase (XO) inhibitor, allopurinol (ALP), on cardiac dysfunction, oxidative-nitrosative stress, apoptosis, poly(ADP-ribose) polymerase (PARP) activity and fibrosis associated with diabetic cardiomyopathy in mice. Diabetes was induced in C57/BL6 mice by injection of streptozotocin. Control and diabetic animals were treated with ALP or placebo. Left ventricular systolic and diastolic functions were measured by pressure,volume system 10 weeks after established diabetes. Myocardial XO, p22phox, p40phox, p47phox, gp91phox, iNOS, eNOS mRNA and/or protein levels, ROS and nitrotyrosine (NT) formation, caspase3/7 and PARP activity, chromatin fragmentation and various markers of fibrosis (collagen-1, TGF-,, CTGF, fibronectin) were measured using molecular biology and biochemistry methods or immunohistochemistry. Diabetes was characterized by increased myocardial, liver and serum XO activity (but not expression), increased myocardial ROS generation, p22phox, p40phox, p47phox, p91phox mRNA expression, iNOS (but not eNOS) expression, NT generation, caspase 3/7 and PARP activity/expression, chromatin fragmentation and fibrosis (enhanced accumulation of collagen, TGF-,, CTGF and fibronectin), and declined systolic and diastolic myocardial performance. ALP attenuated the diabetes-induced increased myocardial, liver and serum XO activity, myocardial ROS, NT generation, iNOS expression, apoptosis, PARP activity and fibrosis, which were accompanied by improved systolic (measured by the evaluation of both load-dependent and independent indices of myocardial contractility) and diastolic performance of the hearts of treated diabetic animals. Thus, XO inhibition with ALP improves type 1 diabetes-induced cardiac dysfunction by decreasing oxidative/nitrosative stress and fibrosis, which may have important clinical implications for the treatment and prevention of diabetic cardiomyopathy and vascular dysfunction. [source]

Index of myocardial performance in patients with type 2 diabetes without hypertension and its relationship with clinical and echocardiographic parameters

JOURNAL OF DIABETES, Issue 1 2009
Hayrettin SAGLAM
Abstract Background:, Diabetes mellitus affects the systolic and diastolic function of the left ventricle (LV). The aim of the present study was to evaluate the index of myocardial performance (IMP), a new Doppler index, in asymptomatic, normotensive patients with type 2 diabetes mellitus (T2DM). Methods:, The study population consisted of 40 asymptomatic normotensive patients with T2DM (22 women, 18 men; mean [±SD] age 49,±,7 years) and 20 healthy controls (13 women, seven men; mean age 45,±,4 years). M-Mode and two-dimensional Doppler echocardiography was performed in all subjects to calculate IMP. Venous blood samples were collected for analysis and body mass index (BMI) was calculated. Results:, In normotensive T2DM patients, the mitral E wave was decreased, whereas mitral A wave, mitral E/A ratio, and septal wall thickening were increased compared with values obtained for the control group. The IMP was higher in normotensive T2DM patients than in the control group (P = 0.004). There was a significant correlation between IMP and triglyceride (TG) levels (P,<,0.001), mitral E wave (P,<,0.001), mitral E/A ratio (P,<,0.001), ejection fraction (P = 0.001), fasting blood glucose (P =0.007), LV systolic dimension (P,<,0.001), duration of diabetes (P = 0.017), and BMI (P = 0.029). Stepwise multiple regression analysis demonstrated that only TG levels (, = 0.355, t = 2.487, P = 0.017) and the mitral E/A ratio (, = ,0.384, t = ,2.690, P = 0.011) had an independent effect on IMP. Conclusion:, The results of the present study indicate that IMP is increased in normotensive T2DM patients. The findings suggest that increased IMP may be an early sign of diabetic cardiomyopathy in normotensive diabetic patients with preserved LV function. [source]

Cardiac disorders in farmed adult brown trout, Salmo trutta L.

JOURNAL OF FISH DISEASES, Issue 4 2000
C Mercier
During summer in Brittany, France, sea farmed brown trout, Salmo trutta L., regularly experience a high mortality rate which is associated, at least in part, with cardiac disorders (aneurysms and infarcts). The present study is preliminary to a more extensive research programme, the objective of which is to determine to what extent the physiological performance of the cardiovascular system of brown trout is affected by the environmental conditions the fish experience in farm cages. We conducted a 2-week in situ experiment during which the heart rate of eight sea water acclimatized individuals was telemetered using acoustic tags. During the experimental period, water temperature ranged from 16.0 to 17.6 °C. Water oxygen saturation was above 80% at all times and salinity was very high (35.5,) but stable. Although they were unfed and not active, seven of out the eight tagged animals displayed near maximum heart beat frequencies, which ranged between 83 and 98 beats per minute (bpm). On the other hand, the eighth animal exhibited medium-range heart rates (50,70 bpm). Using phase delay maps, we established that the maximum heart rate of brown trout at 17 °C was in the range of 96,100 bpm. This result suggests that in our experimental conditions, the heart rate of most of our inactive fish was between 85 and 100% of maximum myocardial performance. We hypothesize that the cardiac failures observed in brown trout during summer are most likely a result of strenuous workloads imposed on the cardiovascular system by a combination of elevated temperature, high salinity and possibly season-related decreased hypo-osmoregulatory abilities. [source]

Effect of dantrolene in an in vivo and in vitro model of myocardial reperfusion injury

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2000
B. Preckel
Background: In skeletal muscle, dantrolene reduces free cytosolic calcium by inhibiting calcium release from the sarcoplasmic reticulum. A similar effect in ischemic-reperfused heart cells would protect myocardial tissue against reperfusion injury. We tested the hypothesis that dantrolene infusion during reperfusion protects the heart against reperfusion injury. Methods: Isovolumetric beating rat hearts were subjected to 30 min of ischemia followed by 60 min of reperfusion. Left ventricular (LV) developed pressure (LVDP) and creatine kinase release (CKR) were determined as indices of myocardial performance and cellular injury, respectively. In the treatment groups, dantrolene (25 (DAN25) or 100 (DAN100) ,mol l,1) was infused during the first 15 min of reperfusion; control hearts received the respective concentration of the vehicle (mannitol (CON25, CON100), each group n=7). To investigate the effects of dantrolene on reperfusion injury in vivo, 18 chloralose-anesthetized rabbits were subjected to 30 min occlusion and 180 min reperfusion of a major coronary artery. LV pressure (LVP), cardiac output (CO), and infarct size were determined. During the last 5 min of ischemia, nine rabbits received 10 mg kg,1 dantrolene intravenously (DAN). Another nine rabbits received the vehicle (dimethylsulfoxide) and served as controls (CON). Results: In isolated rat hearts, there was no recovery of LVDP in any group. Total CKR during 1 h of reperfusion was 845±76 (CON100) and 550±81 U g,1 dry mass (DAN100, P<0.05). In rabbits in vivo, hemodynamic baseline values were similar between groups (CON vs. DAN: LVP, 99±6 (mean±SEM) vs. 91±6mm Hg, P=0.29; CO, 252±26 vs. 275±23 ml min,1, P=0.53). During coronary artery occlusion, LVP and CO were reduced in both groups (CON: LVP, 89±3%; CO, 90±5% of baseline values) and LVP did not recover to baseline values during reperfusion (51±5% (CON) vs. 67±7% (DAN) of baseline, P=0.10). Infarct size was 41±4% of the area at risk in controls and 37±6% in dantrolene treated hearts (P=0.59). Conclusions: Dantrolene reduced CKR, indicating an attenuation of lethal cellular reperfusion injury in isolated rat hearts. However, in the rabbit in vivo, there was no effect on the extent of reperfusion injury after regional myocardial ischemia. [source]

Maximizing management of patients with decompensated heart failure

CLINICAL CARDIOLOGY, Issue S3 2000
E. Loh M.D.
Abstract Patients with decompensated congestive heart failure can be categorized into those with either acute or chronic presentations. Patients with acute decompensated heart failure most often have an acute injury that affects either myocardial performance (i.e., myocardial infarction) or valvular/chamber integrity (mitral regurgitation, ventricular septal rupture), which leads to an acute rise in left ventricular (LV) filling pressures resulting in pulmonary edema and dyspnea. Therapy for these patients is aimed at treating the underlying cause of the myocardial injury as well as pharmacologic strategies to reduce LV filling pressures and to improve cardiac performance. In contrast, the therapy of patients presenting with decompensated heart failure in the setting of chronic LV systolic dysfunction, treated with angiotensin-converting enzyme inhibitors, digoxin, diuretics, and maybe beta blockers, represent a poorly defined clinical entity that lacks clear guidelines for treatment. These patients can present with symptoms of volume overload and/or low cardiac output without evidence for a volume overloaded state. Potential diagnostic and therapeutic approaches include (1) a pulmonary artery catheter for invasive hemodynamic monitoring, (2) intravenous inotropic therapy, (3) LV mechanical assist device therapy, and (4) cardiac transplantation. This review presents some of the advantages and disadvantages of each of these interventions for patients with chronic systolic dysfunction who present with decompensated symptoms and require specialized management in the hospital setting. [source]

Circulating IGF-I levels are associated with increased biventricular contractility in top-level rowers

CLINICAL ENDOCRINOLOGY, Issue 2 2008
Giovanni Vitale
Summary Background, The intensive physical activity is often associated with cardiac changes. Objectives, (i) To evaluate the IGF-I system and myocardial structure and function by standard Doppler echocardiography and Tissue Doppler in athletes and sedentary controls; and (ii) to determine any relationship between IGF-I system and echocardiographic parameters. Methods, Nineteen male top-level rowers and 19 age-matched healthy sedentary male controls underwent blood determination of fasting serum IGF-I, IGFBP-3 and acid-labile subunit levels and standard Doppler echocardiography combined with pulsed Tissue Doppler of posterior septal wall, left ventricular (LV) lateral mitral annulus and right ventricular (RV) tricuspid annulus. Myocardial presystolic (PSm), systolic (Sm), the ratio of early diastolic (Em) to atrial (Am) velocities as well as myocardial time intervals were calculated. Results, Rowers had higher serum IGF-I levels (P = 0·04), higher biventricular cavity dimensions and wall thicknesses compared to controls. They also had better LV and RV myocardial function than controls. In the rowers, IGF-I was associated with LV ejection fraction (r = 0·50, P = 0·03), RV PSm velocity (r = 0·55, P = 0·01) and with RV myocardial precontraction time (r = ,0·57, P = 0·01). These associations remained significant after adjusting for age and heart rate. Conclusions, Top-level athletes showed higher IGF-I levels and a better myocardial performance than controls, particularly for the RV systolic activity. The independent correlations between IGF-I and systolic parameters of the left (ejection fraction) and right (PSm velocity and precontraction time) ventricles may possibly indicate a role of IGF-I system in the modulation of myocardial inotropism in athletes. Further studies are needed to confirm this hypothesis. [source]

Exercise capacity and cardiovascular changes in patients with ,-thalassaemia major

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 6 2006
Filippo Tocco
Summary Despite the introduction of deferoxamine, 50% of thalassaemia major patients die before the age of 35 years predominantly from iron induced heart failure. Indeed, the assessment of myocardial performance may be of particular interest since it can reveal an early myocardial dysfunction. By using impedance cardiography and mass spectrometry, we studied the cardiac function and the oxygen extraction ratio (O2ER) of 14 thalassaemic patients and 15 control healthy subjects during an incremental cycle-ergometer test. The achieved mechanical power output and the relative O2 uptake did not reach any significant difference between groups. At the highest workload, O2ER reached significantly higher values in thalassaemic patients versus control subjects while the relationship between cardiac index (CI) and O2ER (CI/O2ER) decreased showing a lower contribution of cardiovascular system to maintain O2 uptake. Results of this study imply that CI/O2ER allows an early diagnosis of the iron induced myocardial dysfunction, whereas it is not clinically patent yet. To our knowledge, this is the first study revealing an O2ER pivotal role as compensatory mechanism to maintain a normal working capacity in subjects suffering from thalassaemia major. [source]