Search results for "consumption"
showing 10 items of 1796 documents
INTERACTIONS OF ISOPRENALINE AND PROSTAGLANDIN E2 WITH RESPECT TO MYOCARDIAL CONTRACTILE FORCE, CORONARY VASCULAR RESISTANCE AND MYOCARDIAL OXYGEN CO…
1976
Left ventricular pressure (LVP), left ventricular pressure derivative (LV dp/dtmax), coronary vascular resistance (CVR) and myocardial oxygen consumption (Qo2) were measured simultaneously in isolated, electrically driven hearts of guinea-pigs at constant perfusion rate. 2 LVP, LV dp/dtmax, CVR and Qo2 were greatly decreased by either the addition of prostaglandin E2 (50 ng/ml) to the perfusion fluid or pretreatment of the animals with reserpine. 3 Isoprenaline (0.5 nM to 100 nM) induced increases in LVP, LV dp/dtmax and Qo2. In the presence of prostaglandin E2, there was a parallel shift of the isoprenaline concentration-response curve for LVP and LV dp/dtmax. This effect was not seen, aft…
Impact of ''off-label'' use of ivabradine on exercise capacity, gas exchange, functional class, quality of life, and neurohormonal modulation in pati…
2010
Background: Epidemiologic studies indicate that elevated heart rate (HR) is an independent risk factor for mortality and morbidity in patients (pts) with chronic heart failure (CHF). Clinical trials with b-blockers suggest that HR reduction is an important mechanism of their benefit in pts with stable CHF. Pharmacologic inhibition of the If current now provides the opportunity of pure HR reduction. The purpose of this study was to evaluate the impact of ‘‘Off-Label’’ use of ivabradine on exercise capacity, gas exchange, functional class, quality of life, and neurohormonal modulation in pts with ischemic CHF. Methods: Between January 2008 and June 2008, a graded maximal exercise test with re…
Serum hormones and physical performance capacity in young boy athletes during a 1-year training period
1990
Serum hormones and physical performance capacity in boy athletes (AG; n = 19) were investigated during a 1-year training period (between the ages of 11.6 and 12.6 years). Six young untrained boys served as the control group (CG). The mean serum testosterone concentration increased significantly in AG (P less than 0.05) following the training period from 2.92 nmol.l-1, SD 1.04 to 5.81 nmol.l-1, SD 1.33. Significant differences were not observed in the cortisol, sex hormone binding globulin and growth hormone levels during the follow-up period. The AG clearly increased speed (P less than 0.001), speed-strength (P less than 0.01-P less than 0.001) and anaerobic capacity (P less than 0.001) whe…
Ventilation and Heart Rate Response During Exercise in Normals: Relevance for Rate Variable Pacing
1993
The observation of a close relationship of heart rate to oxygen uptake (HR-VO2) and heart rate to minute ventilation (HR-VE) has been shown to be of particular value in rate variable pacing. However, the impact of anaerobic threshold (AT) for the HR-VO2 and HR-VE slope has been studied less. Twenty-three male and 16 female subjects, mean age 52 +/- 7 years, were selected in whom complete heart catherization and extensive noninvasive studies excluded major cardiopulmonary disease. Semisupine bicycle exercise testing with analysis of respiratory gas exchange was performed using a ramping work rate protocol with work increments of 20 watts/min. At the respiratory AT, determined by the V slope …
Early effects of empagliflozin on exercise tolerance in patients with heart failure: A pilot study
2018
BackgroundSodium-glucose linked transporter 2 inhibition recently emerged as a promising therapy for reducing the risk of heart failure (HF) in patients with type 2 diabetes mellitus (T2DM). However, there is a lack of data endorsing its role in symptomatic HF patients. We sought to evaluate the short-term effects of empagliflozin on maximal exercise capacity in these patients. HypothesisWe postulate tretament with empagliflozin may improve functional capacity in patients with T2DM and established HF. MethodsNineteen T2DM patients with symptomatic HF were prospectively included and underwent cardiopulmonary exercise testing before and 30days after initiation of empagliflozin therapy. A mixe…
Blood lactate production and recovery from anaerobic exercise in trained and untrained boys.
1988
Blood lactate production and recovery from anaerobic exercise were investigated in 19 trained (AG) and 6 untrained (CG) prepubescent boys. The exercises comprised 3 maximal test performances; 2 bicycle ergometer tests of different durations (15 s and 60 s), and running on a treadmill for 23.20±2.61 min to measure maximal oxygen uptake. Blood samples were taken from the fingertip to determine lactate concentrations and from the antecubital vein to determine serum testosterone. Muscle biopsies were obtained from vastus lateralis. Recovery was passive (seated) following the 60 s test but that following the treadmill run was initially active (10 min), and then passive. Peak blood lactate was hi…
Changes in Cardiovascular Performance During an 8-Week Military Basic Training Period Combined with Added Endurance or Strength Training
2008
ABSTRACT The purpose of the present study was to examine the changes in cardiovascular performance (VO2 max) and maximal strength development during an 8-week basic training (BT) combined with emphasized endurance training (ET) or strength training (ST) among 72 conscripts. The emphasized ST and ET programs combined with BT improved VO2 max by 12.0% (p < 0.01) and 8.5% (p < 0.05), while the increase in the control group (normal training) was 13.4% (p < 0.001). Body fat and waist circumference decreased in all groups. Normal training did not increase maximal strength of leg extensors but both ST (9.1%; p < 0.05) and ET (12.9%; p < 0.01) did. In conclusion, the current BT program including a …
Are first ventilatory threshold and 6-minute walk test heart rate interchangeable? A pilot study in healthy elderlies and cardiac patients
2015
International audience; BACKGROUND: Heart rate (HR) at the ventilatory threshold (VT) is often used to prescribe exercise intensity in cardiac rehabilitation. Some studies have reported no significant difference between HR at VT and HR measured at the end of a 6-min walk test (6-MWT) in cardiac patients. The aim of this work was to assess the potential equivalence between those parameters at the individual level. METHOD: Three groups of subjects performed a stress test and a 6-MWT: 22 healthy elderlies (GES, 77 +/- 3.7 years), 10 stable coronary artery disease (CAD) patients (GMI, 50.9 +/- 4.2 years) and 30 patients with chronic heart failure (GHF, 63.3 +/- 10 years). We analyzed the correl…
LACTATE, NOT GLUCOSE, UP-REGULATES MITOCHONDRIAL OXYGEN CONSUMPTION BOTHIN SHAM AND LATERAL FLUID PERCUSSED RAT BRAINS
2006
OBJECTIVE: Failure of energy metabolism after traumatic brain injury may be a major factor limiting outcome. Although glucose is the primary metabolic substrate in the healthy brain, the well documented surge in tissue lactate after traumatic brain injury suggests that lactate may provide an energy need that cannot be met by glucose. We hypothesized, therefore, that administration of lactate or the combination of lactate and supraphysiological oxygen may improve mitochondrial oxidative respiration in the brain after rat fluid percussion injury. We measured oxygen consumption (VO2) to determine what effects glucose, lactate, oxygen, and the combination of lactate and oxygen have on mitochond…
Comparison of low-frequency electrical myostimulation and conventional aerobic exercise training in patients with chronic heart failure.
2005
Physical training is recommended as an efficient therapy in patients with chronic heart failure (CHF). Low-frequency electrical myostimulation (EMS) has recently been suggested as a good alternative to conventional aerobic training. The aim of this study was to compare the effects of EMS and conventional exercise training in patients with moderate to severe CHF.Twenty-four patients with stable CHF (56.7+/-7.3 years, New York Heart Association grades II and III) underwent 5 weeks of exercise training, 5 h a week, using EMS (n=12) or conventional (n=12) training programmes. At baseline and after the training period, patients performed a symptom-limited cardiopulmonary test, a 6-min and a 200-…