Search results for "HEART RATE"
showing 10 items of 887 documents
Assessment of ventilatory thresholds from heart rate variability in five incremental treadmill tests in cross country skiers
2014
Incremental treadmill tests are widely used in the field of exercise physiology for the assessment of Ventilatory Thresholds for clinical and sport oriented issues. The assessment of Ventilatory Thresholds (VTs) from Heart Rate Variability (HRV) is a relatively new approach with increasing popularity because it is a non-invasive and economical method. Nevertheless, this has not been used in Cross Country (XC) Skiing, an endurance sport where the knowledge of VTs holds special importance. The purpose of the study was to assess VTs using the data derived from HRV analysis in the five main XC skiing-related techniques, Double Poling (DP), Diagonal Striding (DS), Nordic Walking (NW), V1 Skating…
QT interval heterogeneities induced through local epicardial warming/cooling. An experimental study
2014
[EN] ntroduction and objectives Abnormal QT interval durations and dispersions have been associated with increased risk of ventricular arrhythmias. The present study examines the possible arrhythmogenic effect of inducing QT interval variations through local epicardial cooling and warming. Methods In 10 isolated rabbit hearts, the temperatures of epicardial regions of the left ventricle were modified in a stepwise manner (from 22 °C to 42 °C) with simultaneous electrogram recording in these regions and in others of the same ventricle. QT and activation-recovery intervals were determined during sinus rhythm, whereas conduction velocity and ventricular arrhythmia induction were determined dur…
The effect of resonance frequency breathing when used as a preparatory exercise in music psychotherapy : A single-case experimental study of a client…
2017
This study aimed at evaluating the possible benefits of starting Integrative Improvisational Music Therapy (IIMT) sessions with 10 min of Resonance Frequency Breathing (RFB), a type of slow breathing known to be beneficial for stress reduction and emotional regulation. A client diagnosed with anxiety disorder and social phobia attended 12 IIMT sessions. Using an alternating treatments design, RFB was systematically alternated with a control intervention (vibroacoustic therapy, VAT). Therapy processes were assessed through the Session Evaluation Questionnaire (SEQ) and the continuous measurement of heart rate variability (HRV), a biomarker of autonomic nervous system response. RFB was consis…
Effect of long-acting β2-agonists olodaterol and formoterol on heart rate and blood pressure in chronic obstructive pulmonary disease patients
2018
Abstract Background Cardiovascular comorbidities are common in chronic obstructive pulmonary disease (COPD), and elevated heart rate reflects increased cardiovascular risk over time, which is associated with unfavourable neurohumoral activation. Long-acting β 2 -agonists (LABAs) are established treatments in COPD, but potentially increase heart rate. We report a post hoc pooled analysis of the effect of olodaterol (5 or 10 μg) or formoterol (12 μg) on heart rate and blood pressure (BP) in Global Initiative for Chronic Obstructive Lung Disease Stage 2–4 COPD patients. Methods Four randomised, double-blind, placebo-controlled, Phase III studies were analysed. Changes in heart rate and systoli…
Device Therapy for Rate Control: Pacing, Resynchronisation and AV Node Ablation
2017
Atrioventricular node ablation (AVNA) is generally reserved for patients whose atrial fibrillation (AF) is refractory all other therapeutic options, since the recipients will often become pacemaker dependent. In such patients, this approach may prove particularly useful, especially if a tachycardia-induced cardiomyopathy is suspected. Historically, an "ablate and pace" approach has involved AVNA and right ventricular pacing, with or without an atrial lead. There is also an evolving role for atrioventricular node ablation in patients with AF who require cardiac resynchronisation therapy for treatment of systolic heart failure. A mortality benefit over pharmacotherapy has been demonstrated in…
Measuring Heart Rate with a Heat Flux Sensor
2021
Different wearable biosignal measurement applications require minimally obtrusive and highly sensitive sensors and methods of transducing the heart pulse into an electric signal. At the same time, the sensors should have minimal power consumption and preferably provide information about more than just the heart rate. In this study, a method employing a heat flux sensor for recording the pulsatile cardiac component of an arterial pulse waveform is presented. The output signals of a conventional photoplethysmography (PPG) sensor and a heat flux sensor were recorded and compared with one another. The results show that a heat flux sensor can be used for measurement of heart pulse, in addition t…
Altered cerebral blood flow velocity features in fibromyalgia patients in resting-state conditions
2017
[EN] The aim of this study is to characterize in resting-state conditions the cerebral blood flow velocity (CBFV) signals of fibromyalgia patients. The anterior and middle cerebral arteries of both hemispheres from 15 women with fibromyalgia and 15 healthy women were monitored using Transcranial Doppler (TCD) during a 5-minute eyes-closed resting period. Several signal processing methods based on time, information theory, frequency and time-frequency analyses were used in order to extract different features to characterize the CBFV signals in the different vessels. Main results indicated that, in comparison with control subjects, fibromyalgia patients showed a higher complexity of the envel…
The effects of the tricyclic antidepressants desipramine, doxepin and iprindole on the isolated perfused rabbit heart.
1974
1. The right sympathetic nerves of isolated perfused rabbit hearts were stimulated electrically (1 msec, supramaximal strength, 15 sec) with increasing frequencies (0.25–20 Hz) at 3 min intervals before and 20 min after starting perfusion with desipramine, doxepin or iprindole. Ventricular rate, right atrial and right ventricular tensions were recorded using the transverse method. 2. Sympathic nerve stimulation caused ventricular arrhythmias in the presence of desipramine (3.3 and 5.0 · 10−6 M) and doxepin (1.6−4.7×10−6 M) but failed to produce arrhythmias in hearts not exposed to drugs, or after iprindole, cocaine and atropine. 3. When desipramine or doxepin was added to Tyrode solution co…
GENETIC AND ENVIRONMENTAL VARIATION IN PERCEIVED EXERTION AND HEART RATE DURING BICYCLE ERGOMETER WORK
1977
The relative contributions of heredity and environment to the variance in heart rate (HR) and rating of perceived exertion (RPE) during the bicycle ergometer work were studied with 14 pairs of male (6 monozygous (MZ) and 8 dizygous (DZ)) and 22 pairs of female (8 MZ and 14 DZ) twins ranging in age from 11 to 20 years. The results showed for both sexes that no significant differences in the intrapair variances of HR and RPE could be observed between the MZ and DZ twin samples. Thus it was concluded that in contrast to several other parameters of the measurements of the physical work capacity HR and RPE are not influenced to any significant degree by the genetic factors.
Cardiovascular and Autonomic Responses to a Maximal Exercise Test in Elite Youngsters
2017
AbstractTo analyze cardiovascular and autonomic responses in elite youngsters, 13 male cyclists (15.43±0.51 years) performed a graded-test until voluntary exhaustion. Oxygen consumption (VO2), blood lactate (BLa), arterial oxygen saturation (SaO2), respiratory exchange ratio (RER) and rating of perceived exertion (RPE) were collected, while heart rate (HR) was registered for heart rate variability (HRV) analyses, looking for linear and nonlinear comparisons. Cyclists reached maximal exertion [RPE: 19.14±0.94; BLa: 8.92±2.51 mmol.L−1; RER: 1.04±0.03; SaO2: 92.43±2.5%] and high-level performance (4.41±0.46 W·Kg−1; 60.77±6.87 ml·Kg·min−1) once over 95% of age-predicted HRmax. VO2 and RPE incre…