Search results for "HEART RATE"
showing 10 items of 887 documents
Role of Bisoprolol in Patients with Long QT Syndrome
2013
Background Long QT syndrome (LQTS) is a disorder of ventricular repolarization usually treated with β-blockers, mostly with propanolol and nadolol. The aim of our study was to evaluate the role of bisoprolol in LQTS patients. Methods A total of 34 patients were evaluated in an average follow-up time of 93 months: 31 months without treatment, 31 months in treatment with nadolol or propanolol and 31 months in treatment with bisoprolol. The average age of patients at diagnosis was 17.3 years. The enrolled patients were followed through a semiannual electrocardiogram and an annual 24-hour Holter monitoring. All patients underwent genotyping, routine hematologic tests, and an echocardiogram. Res…
Heart rate variability is associated with disease severity and portal hypertension in cirrhosis
2023
Introduction: Autonomic nervous system activity in cirrhotic portal hypertension is linked to hyperdynamic circulation. Heart rate variability (HRV) is a validated noninvasive method to assess the sympathovagal balance. To investigate the correlation between HRV parameters and degree of portal hypertension, we studied a cohort of patients with cirrhosis accounting for etiology and treatments. Patients and Methods: In this cross-sectional, observational cohort study, 157 outpatients of both sex with nonalcoholic cirrhosis were assessed by upper gastrointestinal endoscopy to search for esophagogastric varices. Twenty-four-hour electrocardiogram Holter monitoring with 3 HRV parameters measurem…
THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY
2013
The aim of this study was to simulate the activity pattern of rink hockey by designing a specific skate test (ST) to study the energy expenditure and metabolic responses to this intermittent high-intensity exercise and extrapolate the results from the test to competition. Six rink hockey players performed, in three phases, the 20-metre multi-stage shuttle roller skate test, a tournament match and the ST. Heart rate was monitored in all three phases. Blood lactate, oxygen consumption, ventilation and respiratory exchange ratio were also recorded during the ST. Peak HR was 190.7±7.2 beats · min(-1). There were no differences in peak HR between the three tests. Mean HR was similar between the …
Arousal Styles during Public Speaking
2002
The nature of the public-speaking context as a physiologically arousing communication context is well-known. During public speaking, a significant increase in heart rate level above the baseline has been found in various studies. In these studies, arousal styles during speaking have generally been described on the basis of mean heart rates among a group of participants. Individual variation in HR responses has not received much attention. The purpose of the present study was to examine individual differences in heart rate responses during public speaking and to account for these differences in terms of particular explanatory variables. The heart rate curves of 47 speakers were examined one …
Sleep-time physiological recovery is associated with eating habits in distressed working-age Finns with overweight: secondary analysis of a randomise…
2021
Background Association of physiological recovery with nutrition has scarcely been studied. We investigated whether physiological recovery during sleep relates to eating habits, i.e., eating behaviour and diet quality. Methods Cross-sectional baseline analysis of psychologically distressed adults with overweight (N = 252) participating in a lifestyle intervention study in three Finnish cities. Recovery measures were based on sleep-time heart rate variability (HRV) measured for 3 consecutive nights. Measures derived from HRV were 1) RMSSD (Root Mean Square of the Successive Differences) indicating the parasympathetic activation of the autonomic nervous system and 2) Stress Balance (SB) indica…
Cardiorespiratory information dynamics during mental arithmetic and sustained attention
2015
An analysis of cardiorespiratory dynamics during mental arithmetic, which induces stress, and sustained attention was conducted using information theory. The information storage and internal information of heart rate variability (HRV) were determined respectively as the self-entropy of the tachogram, and the self-entropy of the tachogram conditioned to the knowledge of respiration. The information transfer and cross information from respiration to HRV were assessed as the transfer and cross-entropy, both measures of cardiorespiratory coupling. These information-theoretic measures identified significant nonlinearities in the cardiorespiratory time series. Additionally, it was shown that, alt…
Causal brain-heart information transfer during visual emotional elicitation in healthy subjects: Preliminary evaluations and future perspectives
2017
Complex heartbeat dynamics is known to reflect subject's emotional state, thanks to numerous links to brain cortical and subcortical regions. Likewise, specific brain regions are deeply involved in vagally-mediated emotional processing and regulation. Nevertheless, although the brain-heart interplay has been studied during visual emotion elicitation, directional interactions have not been investigated so far. To fill this gap, in this study we investigate brain-heart dynamics during emotional elicitation in healthy subjects through measures of Granger causality (GC) between the two physiological systems. Data were gathered from 22 healthy volunteers who underwent pleasant/ unpleasant affect…
Information Transfer Between Respiration and Heart Rate During Sleep Apnea
2016
It is well-known that sleep apnea affects the respiration and the heart rate (HR), and studies have shown that the cardiorespiratory coupling is also compromised during obstructive sleep apnea (OSA). Furthermore, the classification of hypopneas is challenging, in particular when only ECG-derived features are used. In this context, this study investigates how different ECG-derived respiratory (EDR) signals resemble the respiratory effort during different types of apneas, and how the amount of information transferred from respiration to HR varies according to the respiratory signal used, real or ECG-derived. ECG and respiratory signals of 10 patients suffering from sleep apnea were analysed, …
Effect of diazoxide on left ventricular performance in hypertension.
1975
The effect of diazoxide on left ventricular performance during rest and isometric exercise (handgrip) was examined in 16 unselected hypertensive patients, 6 of whom had been pretreated with the beta-adrenergic blocking agent pindolol. Diazoxide regularly and promptly produced a fall in left ventricular systolic and end diastolic pressures, and an increase in heart rate and left ventricular dp/dtmax. Haemodynamic changes were maximal 2 minutes after injection of the drug and decreased little over the next 8 minutes. After beta-adrenergic blockade, diazoxide caused a more pronounced reduction in left ventricular systolic pressure and a less marked fall in end-diastolic pressure, whilst the di…
The positive inotropic effect of phenylephrine in the presence of propranolol. Increase in time to peak force and in relaxation time without increase…
1978
The effects of phenylephrine on the shape of the contraction curve and on the cyclic adenosine 3',5'-monophosphate (c-AMP) content were studied in electrically driven (frequency 0.2 Hz) cat papillary muscles. All experiments were done in the presence of 1 micron propranolol in order to minimize interference from beta-adrenoceptors. 1. Phenylephrine increased the force of contraction in a concentration-dependent manner. Maximal effects (about 200% of control) occurred at 30 micron phenylephrine. 2. The positive inotropic effect (PIE) of phenylephrine was antagonized by phentolamine. Phentolamine, 5 micron, produced a parallel shift of the concentration-response curve for the PIE of phenyleph…