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PubMedDate not supplied

Impact of dialysis adequacy on cardiac function in pediatric CAPD patients.

BACKGROUND: Left ventricular hypertrophy is a major cause of morbidity and mortality among patients with chronic renal failure. Uremia-related risk factors play a fundamental role in its occurrence, thus better prognosis and prolonged survival can be attained by successful dialytic therapies. OBJECTIVE: To investigate whether dialysis adequacy has a beneficial effect on cardiac structure and function in children receiving continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Cross-sectional study in the Pediatric Peritoneal Dialysis Unit of a university hospital. PATIENTS: Eighteen children, aged 13.3 +/- 2.8 years, being treated with CAPD, and 20 healthy age- and sex-matched control subjects were enrolled in this study. MAIN OUTCOME MEASURES: Echocardiographic evaluation was performed in all subjects. Dialysis adequacy indices [weekly urea (Kt/V) and creatinine clearance (TCCr)] were calculated in the dialysis group. RESULTS: Interventricular septal thickness, left ventricular (LV) posterior wall thickness, LV mass index (LVMI), and LV end systolic and diastolic dimensions were all found to be significantly higher in the CAPD group compared to the control subjects (p < 0.01). Ejection fraction and fractional shortening of the LV were not significantly different between the two groups. Mean Kt/V was 2.02 +/- 0.71 and mean TCCr was 58 +/- 33 L/wk/1.73 m2. There were significant negative correlations between dialysis adequacy indices and LV end systolic and diastolic dimensions (p < 0.05 and p < 0.001). Ejection fraction and fractional shortening were positively correlated with Kt/V (p < 0.01). Systolic and diastolic blood pressures were positively correlated with LVMI (r= 0.501 and r = 0.523). Significant inverse correlations between mean arterial pressure and both Kt/V and TCCr (r = -0.555 and r = -0.520) were detected. CONCLUSION: These data clearly document that cardiac structure and function are remarkably influenced by the uremic state and dialysis therapy in pediatric CAPD patients. The close relationships between echocardiographic findings and dialysis adequacy indices suggest that adequate dialysis has a beneficial effect on cardiac function via effective removal of toxic substances.

Adolescent↗
PubMed2005

S100A1 gene therapy preserves in vivo cardiac function after myocardial infarction.

Myocardial infarction (MI) represents an enormous clinical challenge as loss of myocardium due to ischemic injury is associated with compromised left ventricular (LV) function often leading to acute cardiac decompensation or chronic heart failure. S100A1 was recently identified as a positive inotropic regulator of myocardial contractility in vitro and in vivo. Here, we explore the strategy of myocardial S100A1 gene therapy either at the time of, or 2 h after, MI to preserve global heart function. Rats underwent cryothermia-induced MI and in vivo intracoronary delivery of adenoviral transgenes (4 x 10(10) pfu). Animals received saline (MI), the S100A1 adenovirus (MI/AdS100A1), a control adenovirus (MI/AdGFP), or a sham operation. S100A1 gene delivery preserved global in vivo LV function 1 week after MI. Preservation of LV function was due mainly to S100A1-mediated gain of contractility of the remaining, viable myocardium since contractile parameters and Ca(2+) transients of isolated MI/AdS100A1 myocytes were significantly enhanced compared to myocytes isolated from both MI/AdGFP and sham groups. Moreover, S100A1 gene therapy preserved the cardiac beta-adrenergic inotropic reserve, which was associated with the attenuation of GRK2 up-regulation. Also, S100A1 overexpression reduced cardiac hypertrophy 1 week post-MI. Overall, our data indicate that S100A1 gene therapy provides a potential novel treatment strategy to maintain contractile performance of the post-MI heart.

Adenoviridae↗
PubMed2006

Differential control of cardiac functions by the brain.

1. The idea is introduced that cardiac rate, contractility or atrioventricular (A-V) conduction spread may be controlled independently by the brain. Limited data from reflex studies are cited to support this view. 2. Evidence is presented that individual autonomic post- and preganglionic neurons have quite specific actions on the heart. Premotor and other central neurons can have preferential actions on heart rate, contractility or A-V conduction. 3. The functional implications of selective cardiac control are discussed.

Animals↗
PubMed2003

Effects of childhood bronchiectasis on cardiac functions.

BACKGROUND: Bronchiectasis is still a widespread disease in developing countries. It is an important cause of mortality and morbidity. The information on cardiac involvement in bronchiectasis is limited. However, cor pulmonale is common in patients with chronic lung disease, such as cystic fibrosis. METHODS: We utilized echocardiography and exercise tests, along with clinical scoring, chest radiograph scoring, and pulmonary function tests in 21 patients to determine whether detectable changes in cardiac functions were present, and the nature of their relationship to the underlying disease severity. RESULTS: The ventricular systolic functions were preserved in all patients. Some of the patients had changes in left ventricular diastolic function indices, characterized by abnormal Ewave/Awave (E/A) ratios or isovolumetric relaxation time values. Isovolumetric relaxation time but not E/A ratios was found to have a significant negative correlation with the clinical score. In addition, exercise capacity was decreased in bronchiectatic children. Most of the patients stopped the exercise test due to exhaustion before reaching maximum heart rate. CONCLUSION: Left ventricular diastolic functions are affected in bronchiectasis, and the performance of patients is dependent on their pulmonary status. This is the first study demonstrating the cardiac effects of bronchiectasis according to our survey of the published literature.

Adolescent↗
PubMed2005

Flow mediated dilatation and cardiac function in type 1 diabetes mellitus.

The present study sought to examine the occurrence of subclinical markers of cardiovascular risk and cardiac dysfunction with increasing disease duration in type 1 diabetes mellitus (DM). There are few data on subclinical cardiovascular abnormalities in type 1 DM. The study included 100 patients without any cardiovascular complaints (mean age 46.6 years, range 22 to 63), with a history of type 1 DM ranging from 2 to 36 years, and 75 age-matched controls. Standard 2-dimensional and Doppler echocardiography and pulse-wave tissue Doppler (tD) mapping of systolic (Sm) and diastolic (Em, Am) velocities (12 left ventricular [LV] segments and right-sided cardiac) were performed. An Em/Am ratio of <1 was considered to represent abnormal segmental diastolic function. Flow-mediated dilation (FMD) of the brachial artery, carotid intima media thickness (IMT) measurement, and extensive laboratory analysis were performed. The FMD was reduced, and IMT increased in patients (p < 0.01). Regional tD-derived diastolic and systolic functional abnormalities were observed within the first decade of the disease. Significant correlations were found between FMD and LV segments with tD-derived dysfunction, the duration of DM, and fibrinogen (p < 0.0001 for all). Stepwise regression analysis showed that FMD was the strongest predictor of abnormal segmental function (p < 0.0001). Data further presented as an analysis of tertiles by DM duration show an increasing occurrence of subclinical cardiac dysfunction and cardiovascular risk markers compared with age-matched controls. In conclusion, FMD is associated with abnormal segmental cardiac function in type 1 DM.

Adult↗
PubMed2004

Cytokine-induced modulation of cardiac function.

Cytokines act in an autocrine and/or paracrine fashion to induce a diverse variety of biological responses. Several cardiac diseases are associated with cytokine activation, and such activation significantly influences several physiologic parameters, including cardiac mechanical function. This review summarizes the current concepts regarding the modulation of myocardial function by cytokines and provides rationale for the sometimes-conflicting results in the literature regarding underlying mechanisms and patterns of dysfunction. Although traditionally considered cardiodepressant mediators, contractile responses are complex and bimodal, with an early response (within minutes) of variable direction, stimulatory or depressant, depending on the ambient physiologic milieu and relative contributions of the underlying signaling pathways that are activated. These pathways include sphingomyelinase-, nitric oxide (NO)-, and phospholipase A2-dependent signaling with resultant combined effects on contraction and the Ca2+ transient. This is subsequently followed by a profoundly cardiodepressant late response lasting hours to days, depending on the production of secondary mediators and the combined influence of NO generated from inducible NO synthase, reactive oxygen species, and alterations in beta-adrenergic receptor signaling. The interrelationships between these pathways and the time-dependence of their activation are important considerations in the evaluation of cytokine-dependent dysfunction during both acute cardiac injury and chronic cardiac pathologies.

Animals↗
PubMed2004

Exercise capacity and cardiac function assessed by tissue Doppler imaging in chronic heart failure.

OBJECTIVE: To examine the relation between longitudinal left ventricular function assessed by tissue Doppler imaging (TDi) and exercise capacity in heart failure. SUBJECTS: 153 patients with chronic heart failure from left ventricular systolic dysfunction (ejection fraction < 45%) and 87 age and sex matched controls. METHODS: Echocardiography was used to measure conventional indices of left ventricular systolic function. TDi was used to assess left and right ventricular longitudinal function by measuring mitral and lateral tricuspid annular velocities during the cardiac cycle. Velocities measured at each point were the systolic peak (S(m)) and the diastolic troughs (E(m) and A(m)), corresponding to passive and active (atrial) left ventricular filling. Each patient also underwent treadmill exercise testing with metabolic gas exchange measurements. RESULTS: Left and right ventricular TDi velocities were greater in controls than in patients. Left ventricular ejection fraction (LVEF) correlated with S(m) (r = 0.30, p = 0.0005), but not with E(m), A(m), or the E(m)/A(m) ratio. There were no significant differences between New York Heart Association (NYHA) functional class for any of the TDi variables. Right ventricular indices were not related to exercise capacity. Systolic myocardial motion measured by TDi correlated more closely with peak oxygen consumption (pVO2) (r = 0.35, p < 0.0001) than LVEF (r = 0.21, p < 0.02). The E(m)/A(m) ratio was not correlated with pVO2. In multiple regression, S(m) was the only left ventricular TDi variable to predict exercise capacity independently (p < 0.05). CONCLUSIONS: Exercise capacity and symptoms are poorly related to conventional measures of cardiac function and more closely correlated with indices of longitudinal left ventricular function as assessed by TDi.

Case-Control Studies↗
PubMed2004

Cine-MRI assessment of cardiac function in mice anesthetized with ketamine/xylazine and isoflurane.

Since small-animal MRI generally requires anesthesia, the effect of the anesthetic regimen on the explored organ(s) has to be taken into account for study interpretation. In this work, we assess the influence of ketamine/xylazine and isoflurane anesthesia on left-ventricular (LV) function in the mouse in vivo by cine-MRI. Three groups of animals were anesthetized with ketamine/xylazine (n = 13) and two different concentrations of isoflurane (1.25%, n = 12 and 2.00%, n = 12) delivered in O2/N2O mix. Long- and short-axis cine-MRI was performed to measure end-diastolic volume, stroke volume, ejection fraction and LV wall thickness. Ketamine/xylazine significantly reduced heart rate, cardiac output and wall thickness, but increased stroke volume and end-diastolic volume compared with both isoflurane groups. No differences across all groups were observed in ejection fraction or systolic wall thickening. Breath rate under isoflurane was significantly lower and concentration dependent, whereas heart function was independent of concentration in all measured parameters. These findings are in agreement with echocardiography and catheterization studies. Isoflurane is advantageous for MR studies because it better maintains cardiac function. Taking into account previously obtained myocardial perfusion measurements, isoflurane concentration should, however, be maintained at the minimum required for a stable sleep even if cardiac function is unaffected by higher isoflurane concentrations.

Administration, Inhalation↗
PubMed2003

Impaired cardiac function and IGF-I response in myocytes from calmodulin-diabetic mice: role of Akt and RhoA.

This study characterized the cardiac contractile function and IGF-I response in a transgenic diabetic mouse model. Mechanical properties were evaluated in cardiac myocytes from OVE26 diabetic and FVB wild-type mice, including peak shortening (PS), time to PS (TPS), time to 90% relengthening (TR(90)) and maximal velocity of shortening/relengthening (+/-dL/dt). Intracellular Ca(2+) was evaluated as Ca(2+)-induced Ca(2+) release [difference in fura 2 fluorescent intensity (Delta FFI)] and fluorescence decay rate (tau). Sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA)2a, phospholamban (PLB), Na(+)-Ca(2+) exchanger (NCX), GLUT4, and the serine-threonine kinase Akt were assessed by Western blot. RhoA and IGF-I/IGF-I receptor mRNA levels were determined by RT-PCR and Northern blot. OVE26 myocytes displayed decreased PS, +/-dL/dt, and Delta FFI associated with prolonged TPS, TR(90), and tau. SERCA2a, NCX, and Akt activation were reduced, whereas PLB and RhoA were enhanced in OVE26 hearts. GLUT4 was unchanged. IGF-I enhanced PS and Delta FFI in FVB but not OVE26 myocytes. IGF-I mRNA was increased, but IGF-I receptor mRNA was reduced in OVE26 hearts and livers. These results validate diabetic cardiomyopathy in OVE26 mice due to reduced SERCA2, NCX, IGF-I response, and Akt activation associated with enhanced RhoA level, suggesting a therapeutic potential for Akt and RhoA.

Animals↗
PubMed1992

[Interdependence of preload, afterload and contractility: their relation to cardiac function curve].

Formerly, the major determinants of cardiac performance, i.e., preload, afterload contractility, and heart rate had been considered independent. This individual concept of these determinants was originally advocated by E.H. Sonnenblick in 1960's, providing an extremely useful tool in understanding basic cardiac mechanical physiology. We now know, however, that these determinants of cardiac performance are, in fact, interdependent with each other both at cellular and at ventricular levels. This concept of the interdependency of the determinants, in turn, is of practical importance during the conduct of clinical anesthesia. Since we cannot isolate one determinant from the other, we have to deal with them as they are. Furthermore, monitoring a parameter of one aspects of the patient's cardiac performance is not sufficient to understand or estimate patient's status. It is necessary to integrate these informations to make clinical decision under uncertain situations.

Heart↗
PubMed1986

[Fetal echocardiography. A horizontal study of biometry and cardiac function in utero].

The anatomy and the cardiac growth in normal fetal heart was studied by real-time-directed M-mode ultrasound from the 19th gestation week until term. A correct fetal cardiac M-mode recording was obtained in 94 out of 144 women (65%). Echocardiographic variables were plotted against gestational age and respective correlation coefficients were determined by linear regression analysis. A comparison between the variables was studied by paired t-test. Left ventricular, right ventricular, left atrial and right atrial chamber size, interventricular septum thickness, right and left wall thickness, aortic and pulmonary diameter all increased linearly with age. Right ventricle (10.1 +/- 3.1) was slightly larger than left ventricle (9.2 +/- 2.8 mm) (p less than 0.001), the pulmonary artery (7.9 +/- 1.9 mm) was greater than the aorta (7.6 +/- 2 mm) (p less than 0.001), while no significant difference was noted between left atrium (10.8 +/- 3.5 mm) and right atrium (10.1 +/- 2.6 mm), right ventricular wall thickness (2.7 +/- 0.9 mm) and left ventricular wall thickness (3.0 +/- 1.1 mm). The ratios of left ventricular/right ventricular diameter, left atrial/right atrial and left atrial/aortic diameters, the relative wall thickness and arterial vessels diameters did not change significantly throughout the pregnancy. The ratio interventricular septum/posterior wall thickness was 1.14 +/- 0.36 and ratio of 1.5 or greater was found in 14.5% of the fetal normal heart. The ratio left atrial/aortic diameter was 1.32 +/- 0.21 and left atrium was significantly greater than aorta (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography↗
PubMed1995

Left ventricular geometry and cardiac function in mild to moderate essential hypertension.

To elucidate left ventricular (LV) cardiac structure and function in patients with mild to moderate essential hypertension, we studied the relationship between LV geometry and function. We evaluated LV diastolic and systolic functions by M-mode echocardiography in 91 age-matched normotensive control subjects (NT) and 124 patients with essential hypertension. Hypertensive patients were divided into two groups based on the WHO stage classification: WHO I (n = 76) and WHO II (n = 48). Patients in WHO I and WHO II were further categorized according to the relative wall thickness as normal left ventricle (n = 47), concentric remodeling (n = 29), concentric hypertrophy (n = 25), and eccentric hypertrophy (n = 23). LV diastolic function was significantly decreased in the hypertensive groups compared to NT. There was no significant difference in LV systolic performance among NT, WHO I and WHO II. LV contractility was significantly increased in WHO I compared to NT. In respect to ventricular geometric pattern, LV diastolic function was significantly decreased in both the concentric hypertrophy and eccentric hypertrophy groups. LV systolic dysfunction was noted only in the eccentric hypertrophy group. In conclusion, patients with concentric remodeling had normal systolic and diastolic functions. LV diastolic function was impaired in both the concentric and eccentric hypertrophy groups due to an increase in LVMi. Moreover, LV systolic impairment was noted in the eccentric hypertrophy group due to an inappropriate compensation to LV systolic load.

Adult↗
PubMed1983

A preliminary investigation on the use of thermodilution and echocardiography as an assessment of cardiac function in the cat.

A technique for the determination of cardiac output in the cat by the thermal dilution method is described. The values of cardiac output assessed by thermal dilution and the values of left ventricular function assessed echocardiographically are compared. Values of cardiac output obtained by thermal dilution compare favourably with values obtained by other investigators by indicator dye dilution, the Fick method and electromagnetic flowmeter technique. The technique of thermal dilution in the cat was consistent and simple to perform. The calculation of ventricular volumes and cardiac output echocardiographically using formulae suggested in man was unsuccessful. Such formulae based on assumptions of cardiac shape and contractility do not appear valid in the cat. Statistical analysis demonstrated a positive correlation between the cardiac output determined by thermodilution and the left ventricular diastolic and systolic dimensions determined echocardiographically. A positive correlation was also shown between the cardiac output and the cardiac index, the left ventricular diastolic dimension and the left ventricular systolic dimension and the percent change in minor diameter and the velocity of circumferential fibre shortening. A negative correlation existed between the left ventricular systolic dimension and the velocity of circumferential fibre shortening and the ejection time and the velocity of circumferential fibre shortening.

Animals↗
PubMed1976

Cardiac function in the treatment of arterial hypertension with propranolol.

1. Propranolol, when used for treating arterial hypertension, may influence determinants of both cardiac and vascular function; the consequent changes in cardiac performance may result from the interaction of different and possibly opposite effects. 2. Cardiac funtion was investigated in fifty-four primary hypertensive men in the pretreatment state and after 3 weeks of propranolol therapy at a daily dose of 320 mg. 3. beta-Receptor blockade caused depression of pre-injection left ventricular function, which was unrelated to the direction and the extent of changes in peripheral circulation. 4. The ejection left ventricular function could be either depressed or improved depending on the direction to which treatment shifted the vascular resistance, and consequently, the impedance to left ventricular ejection. 5. Withdrawal of the adrenergic support is probably the major factor responsible for the poor ventricular adaptation to an augmented impedance.

Cardiac Output↗
PubMed2005

Cardiac function after exhaustive open-sea swimming.

AIM: The present study examined the acute effects of exhaustive 25-km open-sea swimming on left ventricular (LV) function and morphology. METHODS: Twenty elite male swimmers (22.3+/-4.1 years) participated in this study. Two-dimensionally guided M-mode echocardiograms, and electrocardiographic, phonocardiographic and carotid pulse tracings were performed simultaneously before and immediately after prolonged exhaustive swimming to evaluate the LV function and morphology, and the cardiac sympathetic outflow. Blood samples were also collected before and after the race to determine the hematocrit and the plasma concentrations of K+, Na+, Ca2+, a-ANP, renin, myoglobulin, CPK-MB, and lactate. RESULTS: Exhaustive swimming was associated with a significant reduction in LV fractional shortening (-13%), ejection fraction (-11%), stroke volume (-25%), and LV internal diastolic diameter (-7%). In contrast, cardiac index was increased by 31%, total peripheral resistance was increased by 7%, and LV circumferential and meridional wall stresses were increased by 101% and 102%, respectively. Significant relationships were found between the increases in total peripheral resistance and LV circumferential wall stress and the decrease in ejection fraction. On the contrast, no significant relationship was found between the increased hematocrit and decreased ejection fraction. Furthermore, the pre-ejection period increased by 11%, the pre-ejection period to LV ejection time ratio increased by 15%, and the electrical to electromechanical systole relationship increased from -8 to 10 ms. Immediately after the race, there were significant increases in hematocrit (9%), and plasma concentrations of a-ANP (211%), renin (161%) and lactate (72%), myoglobulin (421%), and CPK-MB (141%) compared to pre-race values. CONCLUSIONS: In elite athletes, prolonged exhaustive swimming is associated with depressed LV function, as suggested by reduced stroke volume, ejection fraction, and LV fractional shortening. This alteration is mainly due to increased afterload.

Adult↗