Search results for "Supine position"
showing 10 items of 91 documents
Heart rate variability changes at 2400 m altitude predicts acute mountain sickness on further ascent at 3000-4300 m altitudes
2012
Objective: If the body fails to acclimatize at high altitude, acute mountain sickness (AMS) may result. For the early detection of AMS, changes in cardiac autonomic function measured by heart rate variability (HRV) may be more sensitive than clinical symptoms alone. The purpose of this study was to ascertain if the changes in HRV during ascent are related to AMS. Methods: We followed Lake Louise Score (LLS), arterial oxygen saturation at rest (R-SpO2) and exercise (Ex-SpO2) and HRV parameters daily in 36 different healthy climbers ascending from 2400 m to 6300 m altitudes during five different expeditions. Results: After an ascent to 2400 m, root mean square successive differences, high-fre…
Towards understanding the complexity of cardiovascular oscillations: Insights from information theory.
2018
Abstract Cardiovascular complexity is a feature of healthy physiological regulation, which stems from the simultaneous activity of several cardiovascular reflexes and other non-reflex physiological mechanisms. It is manifested in the rich dynamics characterizing the spontaneous heart rate and blood pressure variability (HRV and BPV). The present study faces the challenge of disclosing the origin of short-term HRV and BPV from the statistical perspective offered by information theory. To dissect the physiological mechanisms giving rise to cardiovascular complexity in different conditions, measures of predictive information, information storage, information transfer and information modificati…
P1475Impact of automatic screening and parasternal rights positions in the eligibility of patients with hypertrophic cardiomyopathy for subcutaneous …
2020
Abstract Background A high percentage of failures in the detection of QRS and T wave in patients (pts) with hypertrophic cardiomyopathy (HCM) have been reported. This finding would prevent them from being eligible for an implantable subcutaneous automatic defibrillator (S-ICD). However, recently 2 changes in the detection have been proposed, automatic screening and the use of right parasternal position of the lead. The aim of our work was to study if the elegibility proportion of patients was increased with both 2 advacements. Methods We included 31 patients (18 male)with a diagnosis of HCM and at least 1 risk factor for sudden death, in follow-up at the outdoor clinic of of 2 cardiology …
Selection of blood pressure signal for baroreflex analysis
2020
This study aims to evaluate the strength of the causal coupling among systolic, mean and diastolic blood pressure (SBP, MBP and DBP) with heart period (RR interval) (evaluating cardiac chronotropic baroreflex arm) and peripheral vascular resistance (PVR) (evaluating vascular resistance baroreflex arm) in frequency domain using partial spectral decomposition method. We recorded beat-to-beat RR, SBP, MBP and DBP and PVR values in 39 volunteers during supine rest and head-up tilt. Our results showed that during supine rest the most dominant causal coupling was from DBP to RR in both low and high frequency bands and significantly decreased during orthostasis. The strength of spectral couplings …
Effects of eight weeks of physical training on physical performance and heart rate variability in children
2017
Kraama, Liisa. 2013. Effects of eight weeks physical training on physical performance and heart rate variability in children. University of Jyvaskyla, Department of Biology of Physical Activity. Master’s Thesis in Exercise Physiology. 52 pp. Physical activity and aerobic capacity have decreased among children and adolescents during the last decades. Physically active adults have been shown to have higher heart rate variability (HRV) than less active adults. In adults training-induced changes in physical performance have been shown to be related to increase in HRV, especially in high frequency component (HF), which is a marker of parasympathetic activity. The purpose of this study was to exa…
Isometric endurance test of the cervical flexor muscles - Reliability and normative reference values.
2017
Abstract Objective To obtain reference values for the isometric endurance test (IET) of the cervical flexor muscles, investigate its reproducibility, and compare the results with the maximal isometric strength test (MIST) of the cervical flexor muscles. Design Cross-sectional non-comparative study with single group repeated measurements. Methods Altogether 219 healthy females aged 20–59 years volunteered to participate in the study. The IET was performed in the supine position and MIST seated. The reproducibility was evaluated by the intraclass correlation coefficient (ICC) and an analysis described by Bland and Altman. The relationship between the two measuring methods was evaluated by Pea…
Effects of Nifedipine on Blood Pressure, Arterial Compliance and Left Ventricular Mass in Elderly Patients with Isolated Systolic Hypertension
1989
The aim of this study was to evaluate the effects of acute and chronic administration of slow-release nifedipine (SRN) on blood pressure (BP), aortic index (AI), average wall stress (AWS), left ventricular mass (LVM), and other hemodynamic parameters in elderly patients with isolated systolic hypertension (ISH) (systolic blood pressure [SBP] > 175 mmHg). We studied 10 patients (mean age 73.7 ± 5.6 years) in which after a washout period, in basal conditions, 3 h after the administration of SRN (20 mg), and 180 days after chronic therapy (40 mg daily), we evaluated the changes of BP, HR, AI, AWS, LVM, and other parameters obtained by means of echocardiography. After SRN we observed a signific…
Gastric insufflation pressure, air leakage and respiratory mechanics in the use of the laryngeal mask airway (LMA) in children.
2004
Summary Background : The objective of the present study was to evaluate the prelaryngeal position of the laryngeal mask airway (LMATM) in children, and to determine the influence of mask positioning on gastric insufflation and oropharyngeal air leakage. Methods : A total of 100 children, 3–11 years old, scheduled for surgical procedures in the supine position under general anaesthesia were studied. After clinically satisfactory LMA placement, tidal volumes were increased stepwise until air entered the stomach, airway pressure exceeded 30 cmH2O, or air leakage from the mask seal prevented further increases in tidal volume. LMA position in relation to the laryngeal entrance was verified using…
Microcirculatory Assessment of Arterial Below-Knee Stumps: Near-Infrared Spectroscopy Versus Transcutaneous Oxygen Tension—A Preliminary Study in Pro…
2017
International audience; Objective: To examine metrologic properties of near-infrared spectroscopy (NIRS) versus transcutaneous oxygen tension (TcPO2) for micro-circulatory assessment of vascular transtibial stumps at the stabilized period of prosthesis fitting, as a preliminary step before exploring its ability to predict stump healing, considering the previously identified limits of TcPO2 (borderline area between 15 and 35mmHg).Design: Prospective single-center observational study.Setting: University-based rehabilitation center.Participants: Individuals with unilateral transtibial amputation for peripheral artery disease, at the definitive stage of prosthesis fitting, able to perform a 2-m…
Effect of age on complexity and causality of the cardiovascular control: comparison between model-based and model-free approaches.
2014
The proposed approach evaluates complexity of the cardiovascular control and causality among cardiovascular regulatory mechanisms from spontaneous variability of heart period (HP), systolic arterial pressure (SAP) and respiration (RESP). It relies on construction of a multivariate embedding space, optimization of the embedding dimension and a procedure allowing the selection of the components most suitable to form the multivariate embedding space. Moreover, it allows the comparison between linear model-based (MB) and nonlinear model-free (MF) techniques and between MF approaches exploiting local predictability (LP) and conditional entropy (CE). The framework was applied to study age-related…