Search results for "cardiac output"
showing 10 items of 95 documents
Impaired Cardiopulmonary Exercise Capacity in Patients With Hyperthyroidism
1996
Hyperthyroidism (H) has been implicated as a primary cause of decreased exercise tolerance. To our knowledge, analysis of respiratory gas exchange, an efficient noninvasive method in evaluating cardiopulmonary capacity, has not been performed in patients with H.Using cardiopulmonary exercise testing, 12 consecutive women with Graves' H were examined and controlled in euthyroidism (E). Eighteen women with E, in whom cardiac catheterization had ruled out heart disease, served as control subjects (C).The ventilatory anaerobic threshold was determined by means of the V-slope method. Ergometry was performed with patients in a semisupine position using a continuous ramp protocol of 20 W/min. Echo…
Beta-adrenergic blocking activity and haemodynamic effects in man of K� 1313, a new beta-adrenergic antagonist
1971
The beta-adrenergic blocking activity and haemodynamic effects of o-[2-hydroxy-3-(isopropylamino)-propoxy]-benzonitril (Ko 1313) have been studied in 22 patients. Antagonism of isoproterenol-induced tachycardia was used as a measure of the beta-adrenergic blocking activity. Ko 1313 1.0 mg had its maximum beta-adrenoceptor blocking effect 5–30 min after intravenous injection. Ko 1313 10.0 mg produced maximum betablockade 1–4 h after oral administration. 1.0 mg Ko 1313 injected intravenously had approximately the same beta-adrenergic blocking effect as 1.0 mg propranolol also given intravenously. After intravenous administration Ko 1313 was 3–4 times as potent as the same dose given orally. A…
Studies on the mechanism of mineralocorticoid-induced blood pressure increase in man.
1979
1. To gain insight into the mechanism of mineralocorticoid-induced blood pressure rise in man we performed haemodynamic studies in six normotensive volunteer subjects before and during administration of the synthetic steroid 9α-fluorocortisol (0·8 mg daily) for a period of 6 weeks. In a further study, performed in seven subjects, plasma noradrenaline concentration and reactivity to exogenous noradrenaline were determined before and during administration of the mineralocorticoid. 2. Within the first week of steroid administration an increase in mean arterial blood pressure could be demonstrated, which was due to an increase in cardiac output. After the sixth week the elevated blood pressure …
Application of C1-Esterase Inhibitor During Reperfusion of Ischemic Myocardium
2001
Background—Complement activation during reperfusion of ischemic myocardium augments myocardial injury, and complement inhibition with C1-esterase inhibitor (C1-INH) at the time of reperfusion exerts marked cardioprotective effects in experimental studies. Application of C1-INH in newborns, however, was recently reported to have dangerous and even lethal side effects. This study addresses the essential role of dosage in studies using C1-INH.Methods and Results—Cardioprotection by C1-INH was examined in a pig model with 60 minutes of coronary occlusion followed by 120 minutes of reperfusion. C1-INH was administered intravenously 5 to 10 minutes before coronary reperfusion without heparin at a…
Echocardiographic and angiographic evaluation of left ventricular function during percutaneous transluminal aortic valvuloplasty.
1992
Transesophageal echocardiography was used to study the effect of the balloon inflation on left ventricular function in 20 patients with critical aortic stenosis undergoing balloon valvuloplasty. Balloon inflation caused an increase of end-diastolic (15% to 34%) and end-systolic (57% to 72%) left ventricular volume. Left ventricular wall stress increased from 30 +/- 10 x 10(3) dyn/cm2 at diastole and 121 +/- 40 x 10(3) dyn/cm2 at systole to 44 +/- 11 x 10(3) dyn/cm2 and 191 +/- 55 x 10(3) dyn/cm2, respectively, when the balloon was inflated (P less than 0.05). Turbulent regurgitant jet across the mitral valve increased from 15 +/- 2% to 25 +/- 3% during balloon inflation (P less than 0.01). …
Meox2/Tcf15 Heterodimers Program the Heart Capillary Endothelium for Cardiac Fatty Acid Uptake
2015
Background— Microvascular endothelium in different organs is specialized to fulfill the particular needs of parenchymal cells. However, specific information about heart capillary endothelial cells (ECs) is lacking. Methods and Results— Using microarray profiling on freshly isolated ECs from heart, brain, and liver, we revealed a genetic signature for microvascular heart ECs and identified Meox2/Tcf15 heterodimers as novel transcriptional determinants. This signature was largely shared with skeletal muscle and adipose tissue endothelium and was enriched in genes encoding fatty acid (FA) transport–related proteins. Using gain- and loss-of-function approaches, we showed that Meox2/Tcf15 media…
Dibutyryl cyclic AMP and adrenaline increase contractile force and 45Ca uptake in mammalian cardiac muscle
1973
The effects of dibutyryl cyclic AMP (DB-AMP; 10−3M) and adrenaline (2.2×10−6 M) on contractile force, 45Ca uptake, and total myocardial Ca concentration were investigated in electrically driven left auricles isolated from rat hearts. The experiments were performed at an extracellular Ca concentration of 0.45 mM and at low frequency of stimulation (15 beats/min). 45Ca exposure was 5 min. Under the conditions used, both drugs increased contractile force and enhanced 45Ca uptake (expressed as relative specific activity) by about 30% (DB-AMP) and 40% (adrenaline), respectively. Thus, the results provide evidence that the effects of adrenaline on 45Ca uptake in mammalian cardiac muscle can be mi…
Vascularity, perfusion rate and local tissue oxygenation of tumors derived from ras-transformed fibroblasts.
2007
Tumors derived from ras-transformed rat fibroblasts were investigated in order to gain insight into possible interrelationships between oncogenic transformations and therapeutically relevant parameters of the metabolic micromilieu of solid tumors in vivo. Tumors grew in nude mice after injection of in vitro-passaged cells. Growth rates, early stages of angiogenesis, perfusion and tissue oxygenation were assessed. Compared with the parental cell line, both ras transformants grew very rapidly and exhibited an early onset of angiogenesis. Perfusion rates of one ras-transformed tumor line were similar to those of the parental tumors whereas reduced flow values were detected in tumors of the oth…
Systemic acidemia impairs cardiac function in critically Ill patients.
2021
Background: Acidemia, is associated with reduced cardiac function in animals, but no studies showing an effect of acidemia on cardiac function in humans are reported. In the present study, we examined the effect of acidemia on cardiac function assessed with transpulmonary thermodilution technique with integrated pulse contour analysis (Pulse Contour Cardiac Output, PiCCO™) in a large cohort of critically ill patients. Methods: This was a prospective multicenter observational cross-sectional study of 297 patients from 6 intensive care units in London, England selected from all patients admitted consecutively between May 2018 and March 2019. Measurements of lowest plasma pH and concurrent ass…
Recombinant growth hormone therapy in patients with ischemic cardiomyopathy : effects on hemodynamics, left ventricular function, and cardiopulmonary…
1999
Background —We studied the effects of recombinant growth hormone (rhGH) on exercise capacity and cardiac function in patients with ischemic cardiomyopathy. Methods and Results —Seven patients (aged 55±9 years) with mild to moderate congestive heart failure (ejection fraction 31±4%) who were on standard therapy were included. The patients were studied at baseline, after 3 months of rhGH treatment, and 3 months after rhGH discontinuation. Cardiac function was assessed by exercise capacity, right heart catheterization at rest and after submaximal exercise, MRI, echocardiography, and Holter monitoring. When administered at a dose of 2 IU/d, rhGH doubled the serum concentration of insulin-like …