Search results for "cardiac output"
showing 10 items of 95 documents
Noninvasive Hemodynamic Measurements During Neurosurgical Procedures in Sitting Position.
2017
Neurosurgical procedures in sitting position need advanced cardiovascular monitoring. Transesophageal echocardiography (TEE) to measure cardiac output (CO)/cardiac index (CI) and stroke volume (SV), and invasive arterial blood pressure measurements for systolic (ABPsys), diastolic (ABPdiast) and mean arterial pressure (MAP) are established monitoring technologies for these kind of procedures. A noninvasive device for continuous monitoring of blood pressure and CO based on a modified Penaz technique (volume-clamp method) was introduced recently. In the present study the noninvasive blood pressure measurements were compared with invasive arterial blood pressure monitoring, and the noninvasive…
Breathing 100% oxygen during water immersion improves postimmersion cardiovascular responses to orthostatic stress
2016
Abstract Physiological compensation to postural stress is weakened after long‐duration water immersion (WI), thus predisposing individuals to orthostatic intolerance. This study was conducted to compare hemodynamic responses to postural stress following exposure to WI alone (Air WI), hyperbaric oxygen alone in a hyperbaric chamber (O 2 HC), and WI combined with hyperbaric oxygen (O 2 WI), all at a depth of 1.35 ATA, and to determine whether hyperbaric oxygen is protective of orthostatic tolerance. Thirty‐two healthy men underwent up to 15 min of 70° head‐up tilt (HUT) testing before and after a single 6‐h resting exposure to Air WI ( N = 10), O 2 HC ( N = 12), or O 2 WI ( N = 10). Heart …
Left ventricular diastolic filling alterations in subjects with mitral valve prolapse: A Doppler echocardiographic study
1993
To assess left ventricular diastolic filling in mitral valve prolapse (MVP), we studied 22 patients with idiopathic MVP and 22 healthy controls matched for sex, age, body surface area and heart rate. A two-dimensional, M-mode and Doppler echocardiographic examination was performed to exclude any cardiac abnormalities. The two groups had similar diastolic and systolic left ventricular volumes, left ventricle mass and ejection fraction. Doppler measurements of mitral inflow were: E and A areas (the components of the total flow velocity-time integral in the early passive period of ventricular filling, E; and the late active period of atrial emptying, A), the peak E and A velocities (cm.s-1), a…
Lymphocyte beta-adrenergic receptors in young subjects with peripheral or central obesity: relationship with central haemodynamics and left ventricul…
1994
This study was designed to evaluate total (t) and surface (s) β-adrenergic receptor (BAR) density and their relationship with central haemodynamics and left ventricular function in young subjects with central or peripheral obesity. A total of 31 obese subjects (BMI ≥30.5 kg. m−2 for males and >27.3 kg. m−2 for females) aged less than 40 years and without other risk factors for cardiovascular diseases (smoking, hypertension, diabetes and lipid abnormalities) were studied. Nine had peripheral obesity and 22 central obesity according to WHR values; there were 20 lean controls (BMI <25 kg. m−2 for males and <24.7 kg. m−2 for females). Casual (c) and 24 h ambulatory mean blood pressures (MBP-24 …
Haemodynamic effects of a single intravenous dose of lorcainide in patients with heart disease
1980
The cardiovascular effects of a single i.v. dose (2 mg/kg over 5 min) of lorcainide were studied in 14 patients with heart disease. In the haemodynamic part of the study (6 patients), the aortic and pulmonary systolic, diastolic and mean pressures, left ventricular systolic and end-diastolic pressures, cardiac output and the rate of rise of left ventricular pressure were measured before and for 30 min after administration of the drug. Lorcainide produced a slight and short-lasting decrease in the aortic and pulmonary systolic pressures, and all other pressure values remained unchanged. The cardiac output and systemic vascular resistance were not altered by lorcainide. It consistently depres…
Cardiovascular and autonomic responses to physiological stressors before and after six hours of water immersion
2013
The physiological responses to water immersion (WI) are known; however, the responses to stress following WI are poorly characterized. Ten healthy men were exposed to three physiological stressors before and after a 6-h resting WI (32–33°C): 1) a 2-min cold pressor test, 2) a static handgrip test to fatigue at 40% of maximum strength followed by postexercise muscle ischemia in the exercising forearm, and 3) a 15-min 70° head-up-tilt (HUT) test. Heart rate (HR), systolic and diastolic blood pressure (SBP and DBP), cardiac output (Q̇), limb blood flow (BF), stroke volume (SV), systemic and calf or forearm vascular resistance (SVR and CVR or FVR), baroreflex sensitivity (BRS), and HR variabili…
Left ventricular function response to exercise in normotensive obese subjects: influence of degree and duration of obesity
1992
This study has been designed to evaluate whether duration and severity of obesity can influence left ventricular function response to exercise in obese subjects without other known cardiovascular risk factors such as hypertension, diabetes or hyperlipoproteinemia. A total of 29 obese subjects were included and they were divided, according to their body mass index and to Garrow's criteria as follows: Overweight or mildly obese subjects: body mass index from 25 to 30 kg/m2; moderately obese subjects: body mass index30 and40 kg/m2. Both obese groups were further subdivided according to their duration of obesity evaluated by accurate anamnesis in subgroup A (duration of obesity less than 120 mo…
The Effects of Sympathetic Inhibition on Metabolic and Cardiopulmonary Responses to Exercise in Hypoxic Conditions.
2015
Objective Pre-exertion skeletal muscle glycogen content is an important physiological determinant of endurance exercise performance: low glycogen stores contribute to premature fatigue. In low-oxygen environments (hypoxia), the important contribution of carbohydrates to endurance performance is further enhanced as glucose and glycogen dependence is increased; however, the insulin sensitivity of healthy adult humans is decreased. In light of this insulin resistance, maintaining skeletal muscle glycogen in hypoxia becomes difficult, and subsequent endurance performance is impaired. Sympathetic inhibition promotes insulin sensitivity in hypoxia but may impair hypoxic exercise performance, in p…
Two-dimensional echocardiographic evaluation of left ventricular ejection fraction by the ellipsoid single-plane algorithm: a reliable method for ass…
1995
The reliability of two-dimensional (2D) echocardiographic estimation of left ventricular ejection fraction (EF) is commonly recognized, but no satisfactory data are available about the accuracy of low or very low EF values determined by 2D echocardiography (ECHO-EF). The purpose of our study was to assess the reliability of low ECHO-EF values obtained using a simple time-economical algorithm such as the ellipsoid single-plane area-length method. Radionuclide angiography (RAD-EF) was taken as the standard of comparison. We studied 59 consecutive patients (31 women and 28 men) referred to our echocardiographic laboratory. Both 2D echocardiography and radionuclide angiography were blindly perf…
Pulmonary balloon angioplasty of chronic thromboembolic pulmonary hypertension (CTEPH) in surgically inaccessible cases.
2003
Abstract The clinical course of patients suffering from chronic thromboembolic pulmonary hypertension (CTEPH) depends on the distribution pattern of the thromboembolic material. In patients with thromboembolic findings in the central pulmonary segments pulmonary thrombendarterectomy (PTE) has excellent results and acceptable operative risk. This paper presents two surgically inaccessible cases that were successfully treated with balloon pulmonary angioplasty. Balloon angioplasty improved parenchymal perfusion, increased cardiac index (Delta CI +19.2 % [Case 1], and +15.4 % [2]), reduced pulmonary vascular resistance during follow-up (Delta PVRI -25.0 % [1] and -15.9 % [2]), and is discussed…