Increased cell size in triploid fish likely affects rates of respiratory gas exchange. Respiratory deficiencies can be addressed in fish by adjustments in cardiac output, through changes in heart rate and stroke volume. The aim of this study was to determine whether heart rate differs between triploid and control (diploid) ...

The threshold for the identification of changes in heart rate and the accuracy in estimating heart rate were compared between 20 anaesthetists and 20 non-anaesthetists in a simulated operating theatre, both with and without distraction tasks. Typical operating theatre distractions were simulated by requiring anaesthetists and non-anaesthetists to perform secondary ...

T-wave morphology descriptors are sensitive to drug-induced changes and may be a useful addition to the QT interval in cardiac safety trials. Intrasubject heart rate dependence of T-wave morphology was investigated in a sample of 39 healthy individuals. Ten-second electrocardiograms were obtained from daytime Holter recordings. Duration parameters (QT, ToTe, ...

Hypertonia and heart failures have become two of the main diseases affecting today's human population. A telemetric controlled sensor implant without a battery is being developed and evaluated with in vivo experiments for use as a powerful tool in long-term post surgical evaluation of heart pressure, body temperature and pulse ...

Deforestation is recognized as one of the most significant component in LULC and global changes scenario. It is imperative to assess its trend and the rates at which it is occurring. The changes will have long-lasting impact on regional climate and in turn on biodiversity. In North-East India, one of ...

BACKGROUND: Resting heart rate can predict cardiovascular disease mortality or all-cause mortality. Because of the effect of the alert reaction, heart rates measured out-of-office should have better predictive power than those obtained at clinics. However, only a few studies have described the relationship between heart rate measured by ambulatory blood ...

Arrhythmias in patients with repaired tetralogy of Fallot (ToF) might be due in part to altered autonomic heart rate control caused by altered right ventricle hemodynamics. This study investigated autonomic heart rate control in adolescents with ToF at rest and during unloading of the right ventricle. A total of 17 ...

Heart rate variability refers to the regulation of the sinoatrial node, the natural pacemaker of the heart by the sympathetic and parasympathetic branches of the autonomic nervous system. Heart rate variability is important because it provides a window to observe the heart's ability to respond to normal regulatory impulses that ...

The parameters of heart rate variability and blood pressure variability have proved to be useful analytical tools in cardiovascular physics and medicine. Model-based analysis of these variabilities additionally leads to new prognostic information about mechanisms behind regulations in the cardiovascular system. In this paper, we analyze the complex interaction between ...

The therapeutic strategy of heart rate control for atrial fibrillation (AF) is undergoing a renaissance since several recent randomized trials demonstrated clear advantages over the rhythm control for many patients. Heart rate control for AF is hampered, however, by a dearth of information relating target heart rates to physiological measures ...

STUDY OBJECTIVES: We investigated autonomic balance and resting metabolic rate to explore their possible involvement in obesity in hypocretin/orexin-deficient narcoleptic subjects. METHODS: Resting metabolic rate (using indirect calorimetry) and variability in heart rate and blood pressure were determined in the fasted resting state. Subjects included 15 untreated, hypocretin-deficient male narcoleptics ...

Rate constants for the gas-phase reactions of OH radicals with the C(7)-C(14) 1-alkenes and with E-7-tetradecene and 2-methyl-1-tridecene have been measured at 295 +/- 1 K and atmospheric pressure of air using a relative rate technique. The rate constants obtained (in units of 10(-11) cm(3) molecule(-1) s(-1)) were: 1-heptene, 3.86 ...

OBJECTIVE: To determine the frequency of monitoring of patient vital signs in two wards of a tertiary hospital. METHODS: A retrospective observational study of patient charts from two wards was conducted for a 48-hour period (Sunday and Monday, 23 and 24 October 2005). All vital sign readings from all patient ...

The importance of resting heart rate in predicting the development of hypertension and cardiovascular morbidity and mortality has been demonstrated in a large number of studies. The relationship between high heart rate and cardiovascular mortality held true in studies performed in hypertensive participants. In most epidemiologic studies, the predictive power ...

Although motorcycling performance strongly depends on the characteristics of the motorcycles and capabilities of the riders, little information is available on the physiological profiles of riders. The aim of this study was to evaluate the physical load of official international men's road-race motorcycling competitions. Data were obtained from 34 male ...

The effect of an aversive stimulus represented by contact with a hot plate on the heart rate of Megalobulimus mogianensis was evaluated with electrocardiogram recording in intact snails (N = 8). All stimulated animals showed an increase in heart rate, with mean values ranging from 35.6 +/- 1.2 (basal heart ...

It is well known that autonomic nervous activity is altered under microgravity, leading to disturbed regulation of cardiac function, such as heart rate. Autonomic regulation of the heart is mostly determined by beta-adrenergic receptors/cAMP signal, which is produced by adenylyl cyclase, in cardiac myocytes. To examine a hypothesis that a ...

Rosana G. Moreira, Editor-in-Chief; Texas A&M University

Preparatory heart rate deceleration occurs in tasks with an external focus of attention and is often assumed to facilitate balance performance. However, its effects upon sport-related complex balance movements have not been studied. Heart rate patterns during the preparation period of an acrobatic element (flic-flac) on the balance beam were ...

StressEraser is a commercially marketed biofeedback device designed to enhance heart rate variability. StressEraser makes its internal calculations on beat-to-beat measures of finger pulse intervals. However, the accuracy and precision of StressEraser in quantifying interbeat intervals using finger pulse intervals has not been evaluated against standard laboratory equipment using R-R ...

Our objective was to observe and document cardiovascular side effects of radiofrequency thermocoagulation of the trigeminal ganglion. Forty-eight patients with primary trigeminal neuralgia were enrolled into this study. Continuous electrocardiogram, heart rate, cardiac rhythm changes, and systemic blood pressure were monitored during the procedure of oval foramen puncture, electrode needle ...

PURPOSE: Physician advice and restrictions to patients following a cardiac event can, in some instances, lead patients to be fearful regarding their activities even to the point of inactivity. The purpose of this study was to test whether lawn mowing, one of the activities most strongly discouraged after coronary artery ...

OBJECTIVES: To test the hypothesis that people with a unilateral traumatic transtibial amputation are less active than people without an amputation, and to explore whether both groups have a similar heart rate response while walking. DESIGN: A case-comparison study. SETTING: General community. PARTICIPANTS: Nine subjects with a unilateral traumatic transtibial ...

OBJECTIVE: To evaluate the effect of buprenorphine administration on the cardiovascular and respiratory responses to noxious colorectal distension in conscious rabbits. STUDY DESIGN: Prospective experimental trial. ANIMALS: Fifteen healthy, young adult New Zealand white rabbits (eight female). METHODS: Experiments were performed on conscious rabbits that were instrumented with intraabdominal arterial ...

BACKGROUND: The univentricular circulation after a Fontan procedure is characterized by an abnormal cardiorespiratory response being attributable to an inability to increase stroke volume during exercise. In congenital heart disease a broad QRS complex has been related to increased intracardiac volume and mass being associated with poor ventricular function and ...

OBJECTIVES: The 5-hydroxytryptamine 3 receptor antagonists, including tropisetron, ondansetron, granisetron, and dolasetron are agents used effectively for supportive care. They are used for the prevention and treatment of chemotherapy and radiotherapy-induced emesis. Despite their overall excellent safety profile, some electrocardiographic changes related to heart rate and repolarization were reported. Ondansetron, ...

The purpose of this study is to measure both ECG and BCG(Ballistocariograph) signal of a subject on moving or resting wheelchair and detect the heart rate and respiratory rate and transmit an event message to remote server on emergent situation. To acquire ECG and BCG data, amplifier circuits were composed ...

CONTEXT: Music and surgery. OBJECTIVE: To determine the effect of live classical piano music on vital signs of patients undergoing ophthalmic surgery. DESIGN: Retrospective case series. SETTING AND PATIENTS: 203 patients who underwent various ophthalmologic procedures in a period during which a piano was present in the operating room of ...

In general, it is difficult to compare biological reactions to some kind of stimulation among subjects on the basis of a single physiological parameter such as heart rate variability because there is a large individual variability in its values. A solution to this problem is to utilize the correlation between ...

The authors, using a crossover design, randomly administered, in a single-blind manner, 3 primary intraosseous injections to 61 subjects using: the Wand local anesthetic system at a deposition rate of 45 seconds (fast injection); the Wand local anesthetic system at a deposition rate of 4 minutes and 45 seconds (slow ...

Persons with electromagnetic hypersensitivity (EHS) complain of subjective symptoms such as headaches, insomnia, memory loss etc. resulting from radio frequency (RF) radiation by cellular phones. There have been various EHS provocation studies on heart rate, blood pressure, and subjective symptoms using GSM phones. However, there are few provocation studies on ...

Food intake regulation involves various central and peripheral mechanisms. In this study the relevance of physiological responses reflecting the autonomic nervous system were evaluated in relation to perceived satiety. Subjects were exposed to a lunch-induced hunger-satiety shift, while profiling diverse sensory, physiological, and biochemical characteristics at 15 min intervals. Sensory ...

OBJECTIVE: To evaluate the effect of changes in hemodynamics on the myocardial performance index (MPI) in cats. ANIMALS: 6 mixed-breed cats. PROCEDURES: Cats were anesthetized by administration of thiopental sodium; anesthesia was maintained by administration of isoflurane. Systolic arterial pressure and central venous pressure were measured by use of catheters, ...

The effects of sildenafil on heart rate variability were investigated in 20 healthy male subjects aged 24 (21 to 32) years (median; range). Subjects orally received single 100-mg doses of sildenafil and placebo under randomized double-blind crossover conditions on 2 separate study days. Time domain measures of heart rate variability ...

BACKGROUND: The clinical course and the precipitating risk factors in the congenital long QT syndrome (LQTS) are genotype specific. OBJECTIVES: The goal of this study was to develop a computer algorithm allowing for electrocardiogram (ECG)-based identification and differentiation of LQT1 and LQT2 carriers. METHODS: Twelve-lead ECG Holter monitor recordings were ...

BACKGROUND: Cellular cardiomyoplasty is emerging as a potentially novel therapeutic option for heart failure and typically involves direct intramyocardial injection of donor cells into a beating heart. Yet, limited rates of cell engraftment remain an obstacle to be overcome before cell therapy is fully recognized. Mechanical and biological mechanisms may ...

The present study tested the hypothesis that kappa-opioids modulate the arterial baroreflex control of heart rate in conscious young sheep. Various parameters governing the arterial baroreflex control of heart rate were assessed before and after activation of kappa-opiate receptors (KOR) by i.v. administration of the specific KOR agonist U-50488H (experiment ...

Responses to fear- and sadness-inducing films were assessed using a broad range of cardiovascular (heart rate, T-wave amplitude, low- and high-frequency heart rate variability, stroke volume, preejection period, left-ventricular ejection time, Heather index, blood pressure, pulse amplitude and transit time, and finger temperature), electrodermal (level, response rate, and response amplitude), ...

OBJECTIVE: To assess physiological load in conjunction with individual patterns of match-play activity in junior female tennis players during actual singles tennis competition. METHODS: Eight elite junior female tennis players (n = 8; mean (SD) age, 17.3 (1.9) years) took part in a 2 day invitational tournament. Activity pattern analysis ...

The heart rate response to nicotine may be an important component of the process leading to dependence. The present study is the first to determine the extent to which genetic and environmental sources play a role in various components of the heart rate response. One hundred and ten monozygotic and ...

AIMS: To quantitatively compare the ventricular rate-smoothing (VRS) effects of different ventricular pacing (VP) protocols for atrial fibrillation (AF). METHODS AND RESULTS: Using a recently developed open-source model that can simulate the ventricular response in AF and VP, the performance of fixed-rate pacing and four previously published VRS algorithms were ...

To study the clinico- epidemiological profile of hypertension in a series of hypertensive patients in a town in Eastern Sudan. A sample of 242 hypertensive patients was studied using a structured questionnaire including the clinico-epidemiological features associated with hypertension. Two thirds of the sample were females, 73.6% of whom were ...

BACKGROUND: The effectiveness of recorded harp music as a tool for relaxation for non-human primates is explored in this study. METHODS: Konigsberg Instruments Model T27F-1B cardiovascular telemetry devices were implanted into nine African green monkeys (Chlorocebus aethiops). After post-surgical recovery, animals were exposed to recorded harp music. Telemetry data were ...

BACKGROUND: Tachycardia, often defined as heart rate >100 bpm, has been utilized as a physical sign of hypovolemic shock among the injured for decades without evidence to support its use as a predictor of injury or significant hypovolemia. We sought to determine whether admission heart rate is a valid predictor ...

Anxiety may worsen outcome in psychotic disorders. We assessed anxiety in 44 acutely psychotic subjects and found a positive association with heart rate and blood pressure. Risperidone treatment reduced anxiety but increased heart rate. We concluded that anxiety may adversely affect cardiovascular status in schizophrenia, but the anxiolytic effect of ...

Heart rate variability and postexercise heart rate recovery are used to assess cardiac parasympathetic tone in human studies, but in some cases these indexes appear to yield discordant information. We utilized pyridostigmine, an acetylcholinesterase inhibitor that selectively augments the parasympathetic efferent signal, to further characterize parasympathetic regulation of rest and ...

The geometry of the Poincaré plot of RR intervals is considered and its basic descriptors are defined in terms of the second moment of a distribution of points in a plane. One of the standard descriptors, SD1, is redefined and used to define two new descriptors, SD1(UP) and SD1(DOWN), whose ...

BACKGROUND: Autonomic nervous systemic imbalance, as reflected by altered heart rate variability, is associated with adverse clinical sequelae. Before heart rate variability can predict adverse responses to interventions at delivery, changes compared to the non-pregnant state should be explored. METHODS: Twenty-four normal healthy volunteer women and 22 pregnant women at ...

OBJECTIVE: To evaluate the ability of pre-defined clinical criteria to identify patients who subsequently suffer cardiac arrest, unplanned intensive care unit admission or unexpected death; to determine the ability of modified criteria to identify these patients. DESIGN: Nested, matched case-control study. SETTING: Seven Australian public hospitals. PATIENTS AND PARTICIPANTS: Four ...

In humans, anxiety is accompanied by changes in autonomic nervous system function, including increased heart rate, body temperature, and blood pressure, and decreased heart rate variability. In rodents, anxiety is inferred by examining anxiety-related behavioral responses such as avoidance and freezing, and more infrequently by assessing autonomic responses to anxiogenic ...