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Heart Rate Response (heart + rate_response)
Selected AbstractsHeart Rate Response to Intravenous Catheter PlacementACADEMIC EMERGENCY MEDICINE, Issue 9 2003Joel M. Bartfield MD Abstract Objective: To investigate the relationship between change in heart rate and pain and anxiety caused by intravenous catheter (IV) placement. Methods: An observational study was performed in a university-based tertiary care emergency department. Patients who required IV placement as part of their management were considered as possible subjects. Heart rates were recorded at the following times: baseline, tourniquet placement, and IV placement. Immediately after IV placement, subjects recorded pain and anxiety scores using 100-mm visual analog scales. Percentage change in heart rate (compared with baseline) was calculated at time of tourniquet placement (anxiety) and IV placement (pain). Simple linear regression analyses were performed comparing pain scores with percent change in heart rate at the time of IV and tourniquet placement. Significance was defined as p < 0.05. Results: Ninety subjects were enrolled. Subjects had a mean age of 48 years, and 54% were women. There was a normal distribution of heart rate changes, with greater than 80% of all subjects having a 10% or less change in heart rates. The results of the analysis of pain scores versus percentage change in heart rate at IV placement yielded a Pearson correlation coefficient of 0.13 (p = 0.2). The results of the analysis of anxiety scores versus percentage change in heart rate at tourniquet placement yielded a Pearson correlation coefficient of 0.014 (p = 0.9). Conclusions: Changes in heart rate do not correlate with pain and anxiety associated with IV placement. [source] Safety of Spectator Sports: Blood Pressure and Heart Rate Responses in Baseball and Football FansJOURNAL OF CLINICAL HYPERTENSION, Issue 10 2010Franklin H. Zimmerman MD No abstract is available for this article. [source] Initial symptoms and reactions to trauma-related stimuli and the development of posttraumatic stress disorderDEPRESSION AND ANXIETY, Issue 2 2005Karin Elsesser Ph.D. Abstract We investigated laboratory and experimental variables as predictors of the development of posttraumatic stress disorder (PTSD). Evoked heart rate response to trauma-related pictures, attentional bias in the dot-probe task, and viewing time were assessed in 35 victims of a traumatic event and again after 3 months. Data was compared to 26 control participants. At first assessment trauma victims showed heart rate (HR) acceleration and controls showed HR deceleration to trauma-related material. The group of trauma victims improved clinically over time. Predictors of the number of PTSD symptoms after 3 months were re-experiencing (33% of the variance) and amplitude of the evoked HR reaction to trauma-related pictures (15%). The two variables were highly correlated. Trauma victims were also more anxious, viewed trauma-related pictures for a longer time, and had a longer reaction time in the dot-probe task (but no distinct attentional bias) than control participants. Results indicate that specific fear responses and re-experiencing contribute to the development of posttraumatic stress disorder. Depression and Anxiety 21:61,70, 2005. © 2005 Wiley-Liss, Inc. [source] Cardiovascular responses to pacifier experience and feeding in newborn infantsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2001Morris Cohen Abstract This study examined the effects of sucking on a pacifier immediately before feeding on cardiovascular responses to feeding. Twenty-eight bottle-feeding infants were studied at 12 to 40 hr of age. Blood pressure and heart rate measurements were made during three periods: Period 1,while infants rested in their cribs before a regularly scheduled feeding, Period 2,while being held by the feeder immediately before feeding, and Period 3,during the first 3 to 5 min of feeding. Half of the infants were given a pacifier during Period 2. Blood pressures and heart rates increased across the periods; however, increases in systolic blood pressure during feeding were reduced for the group of infants given a pacifier prior to feeding. We suggest that cardiovascular responses to feeding in infants are comprised of multiple elements. Most of the systolic blood pressure responses to feeding are elicited by sucking whereas the heart rate response is dependent on both sucking and nutrient intake. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 34,39, 2001 [source] Revisiting Autonomic Dysfunction in End-Stage Renal Disease PatientsHEMODIALYSIS INTERNATIONAL, Issue 3 2003Jocemir R. Lugon Background:,Autonomic dysfunction is frequent in end-stage renal disease (ESRD) patients, but both the relative involvement of the parasympathetic and sympathetic branches and the role of antihypertensive drugs in this setting are still controversial. The present study addressed these issues employing a battery of standard noninvasive cardiovascular autonomic tests. Methods:,Sympathetic (S) function was evaluated by responses of both systolic blood pressure (BP) to passive tilting and diastolic BP to handgrip; parasympathetic (P) function, through the respiratory sinus arrhythmia test and the heart rate response to the 4-s unloaded exercise test. Additional tests influenced by both branches of the autonomic system (P + S) were accomplished by the assessment of heart rate response to the Valsalva maneuver, handgrip, and tilting. Results:,Studied subjects belonged to one of the three groups: ESRD patients not requiring BP medications (n = 11; 8 men, 3 women); ESRD patients receiving antihypertensive therapy (n = 36; 21 men, 15 women); and apparently healthy controls (n = 15; 10 men, 5 women). When the variables grouped according to the branch of the autonomic nervous system predominantly probed were analyzed, only the frequency of impaired sympathetic autonomic responses was higher in ESRD patients not receiving BP drugs compared to controls (55 vs. 23%, P = 0.040). In contrast, when ESRD patients receiving BP drugs were compared to controls, the differences became significant in S, P, and P + S tests (46 vs. 23%, P = 0.045; 22 vs. 3%, P = 0.020; and 34 vs. 13%, P = 0.010, respectively). With the criterion of more than one positive finding in any of the variables examined for diagnosing autonomic dysfunction, the prevalence of autonomic dysfunction was 20% in controls, 64% in ESRD patients not receiving BP drugs (P = 0.005 vs. controls), and 67% in ESRD patients receiving BP drugs (P = 0.043 vs. controls). Conclusions:,ESRD continues to be associated with a high prevalence of autonomic dysfunction. ESRD patients receiving BP drugs were found to have detectable impairment in the entire autonomic system in contrast to those not receiving BP drugs in whom inadequate responses were restricted to the sympathetic branch. [source] Maternal depression and anxiety effects on the human fetus: Preliminary findings and clinical implications,INFANT MENTAL HEALTH JOURNAL, Issue 5 2008John N.I. Dieter Newborns of depressed and anxious mothers show biobehavioral abnormalities suggesting that maternal psychological distress has negative effects on the fetus. Two studies examined the fetuses of depressed and nondepressed mothers: (a) a cross-sectional investigation of fetal activity during the second and third trimesters and (b) an examination of behavioral and heart rate response to vibratory stimulation in late-gestation fetuses. Fetuses of depressed mothers were more active during the fifth, sixth, and seventh gestational months. Assessment of late-term fetuses consisted of a baseline, trials of vibratory stimulation directed towards measuring habituation, and a poststimulation period. During baseline, the fetuses of depressed mothers exhibited a lower heart rate. During stimulation trials, they showed less total movement and appeared to habituate more often. Approximately 35% of the variance in fetal behavior was accounted for by the mothers' depression and anxiety symptoms. Maternal depression may be linked to greater fetal activity during the second and third trimesters and decreased behavioral responsivity during late gestation. The response of late-term fetuses of depressed mothers to vibratory stimulation may reflect "receptor adaptation/effector fatigue" and not true habitation. Future studies should examine the value of clinical interventions provided to the pregnant mother. [source] Cardiovascular Actions of Orexin-A in the Rat Subfornical OrganJOURNAL OF NEUROENDOCRINOLOGY, Issue 1 2007P. M. Smith Orexin-A is a neuropeptide, primarily produced in the lateral hypothalamic/perifornical hypothalamus. Orexin receptors and immunoreactive neuronal fibres are widely distributed throughout the brain, suggesting integrative neurotransmitter roles in a variety of physiological systems. Intracerebroventricular injections of orexin-A increase blood pressure and stimulate drinking, and the subfornical organ (SFO), a circumventricular structure implicated in autonomic control, is a potential site at which orexin may act to exert these effects. We have therefore used microinjection techniques to examine the effects of orexin-A administered directly into the SFO on blood pressure and heart rate in urethane anaesthetised male Sprague-Dawley rats. Orexin-A microinjection (50 fmol) into the SFO caused site-specific decreases in blood pressure (SFO: mean area under curve (AUC) = ,681.7 ± 46.8 mmHg*s, n = 22 versus non-SFO: 63.68 ± 54.69 mmHg*s, n = 15, P < 0.001), and heart rate (SFO: mean AUC = ,26.7 ± 2.8 beats, n = 22, versus non-SFO: mean AUC = 1.62 ± 2.1 beats, n = 15, P < 0.001). Vagotomy did not alter the hypotensive or bradycardic responses elicited by orexin-A microinjection. Prior ,-adrenoceptor blockade with phenoxybenzamine (1 mg/kg, i.v.) masked the orexin-A induced blood pressure (mean AUC = ,122.6 ± 17.6 mmHg*s, n = 4, P < 0.01 paired t-test) and heart rate (mean AUC = ,6.7 ± 1.7 beats, n = 4, P < 0.05, paired test) response. The orexin-A induced heart rate response was attenuated when ,-adrenoceptors were blocked with propranolol (1 mg/kg, i.v.; mean AUC = 0.6 ± 2.8 beats, n = 5, P < 0.01 paired t-test). These studies demonstrate that microinjection of orexin-A into the SFO causes site specific decreases in blood pressure and heart rate which is mediated by a reduction in sympathetic tone. [source] The effects of smoking on selective attention as measured by startle reflex, skin conductance, and heart rate responses to auditory startle stimuliPSYCHOPHYSIOLOGY, Issue 1 2010Justin E. Greenstein Abstract The present study examined the effects of cigarette smoking on attentional processing by measuring nondeprived smokers' (n=39), minimally deprived smokers' (n=36), and nonsmokers' (n=34) startle eyeblink reflex, heart rate, and skin conductance responses (SCR) to acoustic startle stimuli (105 dB) during directed attention tasks. Whereas smokers demonstrated smaller startle responses than nonsmokers during a directed attention visual task, no difference in startle response magnitude emerged between the two smoking groups, nor did we observe an effect of smoking on SCR or heart rate response to the startle stimuli. Our findings suggest that smokers differ from nonsmokers in their selective attention abilities and that smoking does not enhance minimally deprived smokers' selective attention. [source] A comparison of the effectiveness of dexmedetomidine versus propofol target-controlled infusion for sedation during fibreoptic nasotracheal intubationANAESTHESIA, Issue 3 2010C.-J. Tsai Summary Fibreoptic intubation is a valuable modality for airway management. This study aimed to compare the effectiveness of dexmedetomidine vs target controlled propofol infusion in providing sedation during fibreoptic intubation. Forty patients with anticipated difficult airways and due to undergo tracheal intubation for elective surgery were enrolled and randomly allocated into the dexmedetomidine group (1.0 ,g.kg,1 over 10 min) (n = 20) or the propofol target controlled infusion group (n = 20). Intubating conditions and patient tolerance as graded by a scoring system were evaluated as primary outcomes. Intubation was successful in all patients. Satisfactory intubating conditions were found in both groups (19/20 in each group). The median (IOR [range]) comfort score was 2 (1,2 [1,4]) in the dexmedetomidine group and 3 (2,4 [2,5]) in the propofol group (p = 0.027), favouring the former. The dexmedetomidine group experienced fewer airway events and less heart rate response to intubation than the propofol group (p < 0.003 and p = 0.007, respectively). Both dexmedetomidine and propofol target-controlled infusion are effective for fibreoptic intubation. Dexmedetomidine allows better tolerance, more stable haemodynamic status and preserves a patent airway. [source] REFLEXLY EVOKED COACTIVATION OF CARDIAC VAGAL AND SYMPATHETIC MOTOR OUTFLOWS: OBSERVATIONS AND FUNCTIONAL IMPLICATIONSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2006Julian FR Paton SUMMARY 1The purpose of the present review is to highlight the pattern of activity in the parasympathetic and sympathetic nerves innervating the heart during their reflex activation. 2We describe the well-known reciprocal control of cardiac vagal and sympathetic activity during the baroreceptor reflex, but point out that this appears to be the exception rather than the rule and that many other reflexes reviewed herein (e.g. peripheral chemoreceptor, nociceptor, diving response and oculocardiac) involve simultaneous coactivation of both autonomic limbs. 3The heart rate response during simultaneous activation of cardiac autonomic outflows is unpredictable because it does not simply reflect the summation of opposing influences. Indeed, it can result in bradycardia (peripheral chemoreceptor, diving and corneal), tachycardia (nociceptor) and, in some circumstances, can predispose to malignant arrhythmias. 4We propose that this cardiac autonomic coactivation may allow greater cardiac output during bradycardia (increased ventricular filling time and stronger contraction) than activation of the sympathetic limb alone. This may be important when pumping blood into a constricted vascular tree, such as is the case during the peripheral chemoreceptor reflex and the diving response. [source] Abnormal heart rate response to hypercapnia in boys with an apparent life-threatening eventACTA PAEDIATRICA, Issue 12 2002A Edner Aim: To determine instantaneous cardiac variability responses to increased carbon dioxide (CO2) during quiet sleep in infants who may be at risk for the Sudden Infant Death syndrome (SIDS). Methods: The cardiac rate variability before, during and after a CO2 challenge was examined in 41 infants who had experienced an apparent life-threatening event (ALTE) and 41 gender- and age-matched control infants. Results: The ALTE infants responded to CO2 breathing with a significant increase in R-R intervals, i.e. decreases in heart rate, compared to the controls (45.1% increase in R-R intervals vs. 41.4%; p= 0.005). The differences between ALTE infants and controls depended primarily on the boys' responses. Conclusion: ALTE infants, particularly ALTE boys, have an autonomic dysfunction,lower sympathetic stimulation and/or inhibited vagal withdrawal when stressed with CO2. The outcome might provide clues to the mechanisms underlying the cardiovascular processes contributing to the terminal event in SIDS. [source] Effects of prenatal visual stimulation on growth and heart rate in bobwhite quail (Colinus virginianus)DEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2006Merry J. Sleigh Abstract This study examined the effects of prenatal visual stimulation on bobwhite quail embryos' growth and heart rate. No differences in growth rate were found between embryos exposed to visual stimulation during the late prenatal period and control embryos. Embryos exposed to visual stimulation throughout incubation maintained lower heart rates in response to visual stimulation than did naïve embryos. In a subsequent experiment, naïve embryos that underwent an egg-opening procedure exhibited heart rates that were lower than embryos measured in intact eggshells. Embryos in opened eggs maintained lower heart rates than comparison embryos across time; however, a less invasive egg-opening procedure led to a quicker heart rate recovery than did a more invasive egg-opening procedure. These findings indicate that prenatal heart rate responses may be mediated by multiple features of the organism's developmental context, including intensity and duration of sensory stimulation. © 2006 Wiley Periodicals, Inc. Dev Psyshobiol 48: 315,324, 2006. [source] Contingency Learning and Reactivity in Preterm and Full-Term Infants at 3 MonthsINFANCY, Issue 6 2008David W. Haley Learning difficulties in preterm infants are thought to reflect impairment in arousal regulation. We examined relationships among gestational age, learning speed, and behavioral and physiological reactivity in 55 preterm and 49 full-term infants during baseline, contingency, and nonreinforcement phases of a conjugate mobile paradigm at 3 months corrected age. For all infants, negative affect, looking duration, and heart rate levels increased during contingency and nonreinforcement phases, whereas respiratory sinus arrhythmia (RSA, an index of parasympathetic activity) decreased and Cortisol did not change. Learners showed greater RSA suppression and less negative affect than nonleamers. This pattern was particularly evident in the preterm group. Overall, preterm infants showed less learning, spent less time looking at the mobile, and had lower Cortisol levels than full-term infants. Preterm infants also showed greater heart rate responses to contingency and dampened heart rate responses to nonreinforcement compared to full-term infants. Findings underscore differences in basal and reactivity measures in preterm compared to full-term infants and suggest that the capacity to regulate parasympathetic activity during a challenge enhances learning in preterm infants. [source] Computer Analysis of the Fetal Heart RateJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 5 2000Patricia Robin McCartney RNC Computer analysis of the fetal heart rate is a technology of the Information Age commercially available for research and clinical practice. Intelligent systems are engineered with algorithms or neural networks designed to simulate expert knowledge. Automated analysis has provided objective, standardized, and reproducible data used to research fetal heart rate responses in the antepartum and intrapartum setting. Perinatal information systems can integrate FHR analysis and data management. [source] The effects of smoking on selective attention as measured by startle reflex, skin conductance, and heart rate responses to auditory startle stimuliPSYCHOPHYSIOLOGY, Issue 1 2010Justin E. Greenstein Abstract The present study examined the effects of cigarette smoking on attentional processing by measuring nondeprived smokers' (n=39), minimally deprived smokers' (n=36), and nonsmokers' (n=34) startle eyeblink reflex, heart rate, and skin conductance responses (SCR) to acoustic startle stimuli (105 dB) during directed attention tasks. Whereas smokers demonstrated smaller startle responses than nonsmokers during a directed attention visual task, no difference in startle response magnitude emerged between the two smoking groups, nor did we observe an effect of smoking on SCR or heart rate response to the startle stimuli. Our findings suggest that smokers differ from nonsmokers in their selective attention abilities and that smoking does not enhance minimally deprived smokers' selective attention. [source] Effects of low dose dexamethasone treatment on basal cardiovascular and endocrine function in fetal sheep during late gestationTHE JOURNAL OF PHYSIOLOGY, Issue 2 2002Andrew J. W. Fletcher This study investigated the effects on ovine fetal basal cardiovascular and endocrine functions of fetal intravenous dexamethasone treatment, resulting in circulating concentrations that were one-fifth of the values measured clinically in human infants following maternal antenatal glucocorticoid therapy. Between 117-120 days gestation (dGA; term: ca 145 dGA), 26 Welsh Mountain sheep fetuses were surgically prepared under general anaesthesia with vascular catheters and a Transonic flow probe positioned around a femoral artery. At 125 ± 1 dGA, fetuses were infused with dexamethasone (2.06 ± 0.13 ,g kg,1 h,1i.v.; n= 13) or saline (n= 13) for 48 h. Daily fetal arterial blood samples were taken and cardiovascular data were recorded continuously (data acquisition system). Pressor, vasoconstrictor and chronotropic responses to exogenously administered doses of phenylephrine, angiotensin II and arginine vasopressin (AVP) were determined at 124 ± 1 (pre-infusion), 126 ± 1 (during infusion) and 128 ± 1 (post-infusion) dGA. Fetal cardiac baroreflex curves were constructed using peak pressor and heart rate responses to phenylephrine. Dexamethasone treatment elevated fetal mean arterial blood pressure by 8.1 ± 1.0 mmHg (P < 0.05), increased femoral vascular resistance by 0.65 ± 0.12 mmHg (ml min,1),1 (P < 0.05), depressed plasma noradrenaline concentrations and produced a shift in set-point, but not sensitivity, of the cardiac baroreflex (P < 0.05). Elevations in fetal arterial blood pressure, but not femoral vascular resistance and the shift in baroreflex set-point, persisted at 48 h following dexamethasone treatment. By 48 h following dexamethasone infusion, basal plasma noradrenaline concentration was restored, whilst plasma adrenaline and neuropeptide Y (NPY) concentrations were enhanced, compared with controls (P < 0.05). Fetal dexamethasone treatment did not alter the fetal pressor or femoral vasoconstrictor responses to adrenergic, vasopressinergic or angiotensinergic agonists. These data show that fetal treatment with low concentrations of dexamethasone modifies fetal basal cardiovascular and endocrine functions. Depending on the variable measured, these changes may reverse, persist or become enhanced by 48 h following the cessation of treatment. [source] Orthostatic heart rate variability analysis in idiopathic Parkinson's diseaseACTA NEUROLOGICA SCANDINAVICA, Issue 5 2006E. Mihci Objectives ,, We evaluated time and spectral analyses of 24-h heart rate variability (HRV) and the heart rate responses to passive tilt in patients with idiopathic Parkinson's disease (IPD) in order to investigate cardiovascular autonomic functions. Material and methods ,, Twenty-three subjects with IPD without autonomic symptoms and 15 age-matched healthy controls were enrolled. Frequency- and time-domain HRV parameters were studied during resting and passive head-up tilt (HUT) test. Results ,, All time-domain parameters were found to be low in patients with IPD. In patients with IPD, both low frequency (LF) and high frequency (HF) decreased during HUT period and no significant change in LF to HF ratio was noted. Both time- and frequency-domain HRV indices showed no correlation with age, disease severity and duration, and with l -dopa medication. Conclusion ,, The results indicate that impairment of autonomic nervous system function in IPD without autonomic symptoms is frequent, and does not show clear association with clinical stage and the age of the patients. [source] Cardiovascular reflex responses after intrathecal ,-conotoxins or dexmedetomidine in the rabbitCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 1-2 2003Duncan W Blake Summary 1.,The effects of thoracic intrathecal doses (1 µg/kg) of the ,2 -adrenoceptor agonist dexmedetomidine and ,-conotoxins MVIIA and CVID on vasoconstrictor and heart rate responses to acute central hypovolaemia were studied in seven chronically instrumented rabbits. 2.,Gradual inflation of an inferior vena cava cuff to reduce cardiac index (CI) by 8% per minute induced progressive vasoconstriction and an increase in heart rate (phase I). At approximately 40% of resting CI, there was sudden decompensation with failure of vasoconstriction and decrease in mean arterial pressure (MAP; phase II). 3.,Both intrathecal MVIIA and CVID decreased resting CI (by 20% at 3 h), but only MVIIA significantly reduced resting MAP (P = 0.003). Dexmedetomidine resulted in transient bradycardia, but no other significant change in the resting circulation. With simulated haemorrhage, the relationship between CI and vascular conductance was shifted after MVIIA (1,3 h after injection) so that there was less vasoconstriction and a reduced increase in heart rate by the end of phase I compared with other treatments (P = 0.002 and P = 0.009, respectively). One hour after injection, dexmedetomidine reduced the slope of the phase I vasoconstrictor response (P = 0.03), but did not significantly alter the end-point of the response. With failure of vasoconstriction and the onset of phase II, vascular conductance was higher after MVIIA compared with controls. Both conotoxins caused progressive failure of vasoconstriction rather than recovery during phase II (P < 0.001). 4.,Intrathecal injections of these drugs to control chronic pain may compromise cardiovascular responses to changes in central blood volume. At the single doses studied, there were significant differences between the responses to simulated haemorrhage after MVIIA or dexmedetomidine compared with CVID, with the prolonged effect after MVIIA most likely to be of clinical significance. [source] | |||||||||||||