Search results for "HEART RATE"
showing 10 items of 887 documents
Long-term parameters of heart rate variability in patients with insulin-resistance.
2019
Heart rate variability (HRV) is defined as the oscillation in both the interval between consecutive heartbeats (considered RR intervals) and consecutives measures of instantaneous heart rates.1 HRV measures the cardiac autonomic function noninvasively1,2 and its reduction is an independent risk factor for cardiovascular events.3 Insulin-resistance is a pathological condition, in which the body’s cells become resistant to insulin effects.4 The aim of our study was to evaluate the relationship between insulin-resistance and the reduction of HRV parameters.
Associations of cardiometabolic risk factors with heart rate variability in 6‐ to 8‐year‐old children: The PANIC Study
2019
BACKGROUND Associations of cardiometabolic risk factors with heart rate variability (HRV) in children are unclear. We examined associations of cardiometabolic risk score (CRS) and individual cardiometabolic risk factors with HRV variables in 6- to 8-year-olds. METHODS The participants were a population-based sample of 443 children participating in baseline measurements of the Physical Activity and Nutrition in Children trial. Cardiometabolic risk factors included waist circumference (WC), insulin, glucose, triglycerides, HDL cholesterol, systolic blood pressure (SBP), and diastolic blood pressure (DBP). CRS was calculated as WC + insulin + glucose + triglycerides - HDL cholesterol + the mea…
Blood pressure and cardiac autonomic nervous system in obese type 2 diabetic patients: effect of metformin administration
2004
Background: Hyperinsulinemia/insulin resistance and elevated plasma free fatty acids (FFA) levels are involved in the hypertension and cardiac sympathetic overactivity. Metformin improves insulin action and lower plasma FFA concentrations. We investigate the possible effect of metformin on arterial blood pressure (BP) and cardiac sympathetic nervous system. Methods: One hundred twenty overweight type 2 diabetic patients were treated by placebo (n = 60) + diet or metformin (850 mg twice daily) (n = 60) + diet for 4 months, to evaluate the effect of metformin treatment on the cardiac autonomic nervous system. Insulin resistance was measured by the Homeostasis Model Assessment (HOMA) index. He…
Cardiorespiratory Fitness, Physical Activity, and Insulin Resistance in Children
2020
Purpose Few studies have investigated the independent and joint associations of cardiorespiratory fitness (CRF) and body fat percentage (BF%) with insulin resistance in children. We investigated the independent and combined associations of CRF and BF% with fasting glycemia and insulin resistance and their interactions with physical activity (PA) and sedentary time among 452 children age 6 to 8 yr. Methods We assessed CRF with a maximal cycle ergometer exercise test and used allometrically scaled maximal power output (Wmax) for lean body mass (LM) and body mass (BM) as measures of CRF. The BF% and LM were measured by dual-energy X-ray absorptiometry, fasting glycemia by fasting plasma glucos…
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…
The effect of prolonged thermal stress on the physiological parameters of young, sedentary men and the correlations with somatic features and body co…
2019
Little is known about the effect of prolonged thermal stress on the physiological parameters of young and sedentary men. The aim of the study was to determine the effect of prolonged thermal stress on the physiological parameters of young men and the correlations with somatic features and body composition parameters. Forty-two sedentary men aged 20.24 ± 1.68 years were exposed to 10-, 12- and 14-minute sauna sessions (temperature: 90-91 °C; relative humidity: 14-16%). The participants' body composition parameters were determined pre-sauna exposure, and their body mass and blood pressure were measured pre and post-sauna treatment. Physiological parameters were monitored during each sauna ses…
Plasma concentration following oral and intramuscular atropine in children and their clinical effects.
1997
In a paediatric population, we compared i.m. v oral atropine premedication to a control group without atropine and determined atropine plasma concentrations (APC). Forty-five children were randomly assigned to one of three groups. Group I received atropine, 20 micrograms.kg-1 i.m., 15 min prior to induction. Group II received atropine, 30 micrograms.kg-1 orally, group III received no atropine. APC (expressed as percent of muscarine-2 receptor subtype occupancy), heart rate, rectal temperature, and salivation were determined before atropine, and 15, 25, 45, 60, 90, 120 (no APC), and 150 min following atropine. Only 10-20% of the M2-cholinoceptors were occupied after oral atropine with a peak…
Microwave effects on isolated chick embryo hearts.
1986
This study was designed to examine the effects of microwaves on the electric activity of hearts as a means of elucidating interactive mechanisms of nonionizing radiation with cardiac tissue. Experiments were performed on isolated hearts of 9-12-day-old chick embryos placed in small petri dishes. Oxygenated isotonic Ringer's solution at 37 degrees C permitted heart survival. Samples were irradiated at 2.45 GHz with a power density of 3 mW/cm2. The heart signal was detected with a glass micropipet inserted into the sinoatrial node and examined by means of a Berg-Fourier analyzer. Pulsed microwaves caused the locking of the heartbeat to the modulation frequency, whereas continuous wave irradia…
Static magnetic field influence on rat brain function detected by heart rate monitoring.
2004
The aim of the present study was to identify the effects of a static magnetic field (SMF) on rat brain structures that control autonomic functions, specifically heart rate and heart rhythmicity. The experiments were carried out on 44 male Wistar rats under ketamine-xylazine anesthesia. SMF was induced using samarium-cobalt fused magnets (20 x 20 x 10 mm in size) placed bitemporally. Magnetic induction intensity was 100 mT on the surface of the head. Duration of magnetic field application was 15 min. An electrocardiogram was recorded from limb lead II, and both heart rate (average duration of cardiac cycles) and heart rhythmicity were analyzed before and after SMF application. SMF evoked cha…
Mutual Information Analysis of Brain-Body Interactions during different Levels of Mental stress
2019
In this work, we analyze brain-heart interactions during different mental states computing mutual information (MI) between the dynamic activity of different physiological systems. In 18 healthy subjects monitored in a relaxed resting state and during a mental arithmetic and a serious game task, multichannel EEG, one lead ECG, respiration and blood volume pulse were collected via wireless non-invasive biosensors. From these signals, synchronous 300-second time series were extracted measuring brain activity via the δ, θ, α, and β EEG power, and activity of the body district via the ECG R-R interval η, the respiratory amplitude ϱ and the pulse arrival time π. MI was computed using a linear est…