Changes In Mean Heart Rate Research Articles

Influence of body mass loss on changes in heart rate during exercise in the heat: a systematic review.

The purpose of this review was to compare the changes in heart rate (HR) for every 1% change in body mass loss (ΔBML) in individuals while exercising in the heat. PubMed, SPORTDiscus, ERIC, CINAHL, and Scopus were searched from the earliest entry to February 2013 using the search terms dehydration, heart rate, and exercise in various combinations. Original research articles that met the following criteria were included: (a) valid measure of HR, (b) exercise in the heat (>26.5° C [79.7 °F]), (c) the level of dehydration reached at least 2%, (d) a between-group comparison (a euhydrated group or a graded dehydration protocol) was evident, and (e) for rehydration protocols, only oral rehydration was considered for inclusion. Twenty articles were included in the final analysis. Mean values and SDs for HR and percentage of body mass loss immediately after exercise were used for this review. The mean change in HR for every 1% ΔBML was 3 b·min-1. In trials where subjects arrived euhydrated and hypohydrated, the mean change in HR for every 1% ΔBML was 3 and 3 b·min-1, respectively. Fixed intensity and variable intensity trials exhibited a mean HR change of 4 and 1 b·min-1, respectively. Exercising in the heat while hypohydrated (≥2%) resulted in an increased HR after exercise. This increase in HR for every 1% ΔBML exacerbates cardiovascular strain in exercising individuals, thus causing decrements in performance. It should be encouraged that individuals should maintain an adequate level of hydration to maximize performance, especially in the heat.

Clinical outcome of the off-pump coronary artery bypass surgery- a comparison between combined high thoracic epidural anaesthesia with GA and GA alone

Background: The common challenges for the cardiac anaesthesiologist during off pump coronary artery surgery (OPCAB) include haemodynamic stability during the different stressful surgical events and multiple cardiac manipulations, providing adequate myocardial protection, and obtaining effective postoperative analgesia leading to early discharge from the intensive care unit. Objective: This study has been undertaken with a view to find out whether a combined high thoracic epidural anaesthesia (HTEA) with general anaesthesia (GA) is safe and more efficient in providing overall cardiovascular stability as well as improving the parameters leading to a better outcome in terms of a shorter and more predictable road maps to recovery. Methods: Sixty patients aged within 40-70 years, without having any coagulopathy disorder, any emergency surgery or left main disease scheduled for CABG on beating heart were enrolled in prospective, randomized observational comparative study. Patients were divided in two groups. In group A patients received GA alone and in group B patients received high thoracic epidural anaesthesia with GA. The parameters including heart rate, SPO2, CVP, arterial blood pressure, ECG, and ABG analysis were recorded before induction, during induction, intubation and during different events of the surgery. Post operative pain score, sedation score, ventilator hour, duration in the ICU stay, rescue analgesic need and post operative complications was assessed and recorded. Results: significant per-operative mean heart rate changes were observed all the events except at wound closure and during anastomosis with D1/D2 and the mean difference of mean arterial pressure at intubations, skin incision, sternotomy, pericardiotomy, during anastomosis of distal end of the graft with RCA, PDA, LCX and D1/D2 were observed statistically significant (p<0.05). No incidence of different arrhythmia occurred in group B, premature ventricular complex (PVC) was statistically significant (p<0.05) between two groups. No significant change was found in per-operative pH of arterial blood, PaCO2 and PaO2 changes at different times. Post operative pain score (VAS 0-100) in different time interval was found significant (p<0.05) change between two groups in all follow-up times. Status of rescue analgesics were observed statistically significant (p<0.05). The mean ventilator hours were 7.4±1.09 hours in group A and 5.3±0.81 hours in group B. The mean ICU stay was 72.9±9.2 hours in group A and 57.1±12.0 hours in group B. No post-operative complication was observed in both groups. The data were compiled and analyzed by using statistical software SPSS (ver. 12.0) and significance test performed by unpaired t test and Chi square test. P value <0.05 was considered as statistically significant. Conclusion: Both anaesthetic techniques are equally safe but better clinical outcome of the OPCAB surgery with the high thoracic epidural anaesthesia with GA. DOI: http://dx.doi.org/10.3329/jbsa.v22i2.18142 Journal of BSA, 2009; 22(2): 54-60

The Repeatability of Gait Speed and Physiological Cost Index Measurements in Working Adults

To determine the performance characteristics of gait speed measurements and the physiological cost index (PCI; heart rate change/gait speed) in working adults. Gait speeds, heart rate changes, and non-steady state PCIs were calculated in 61 volunteers who worked in our health sciences center. These subjects completed 9 separate 100-foot walk tests in 3 separate sessions. The mean heart rate change after a 100-foot walk was 16.6 ± 8.1 beats per minute. The mean gait speed was 76.1 ± 9.6 meters per minute, and the mean PCI was 0.22 ± 0.11 beats per meter. There were highly significant correlations among all measurements on the 9 separate tests (correlation coefficients 0.41-0.95); gait speed measurements had the highest correlations (0.91-0.95). In a multivariable model hypertension and arthritis were associated with reduced gait speeds. Gait speed, heart rate changes, and non-steady state PCIs have good repeatability when measured over short walks. This information provides a rapid physiological assessment and a method for measuring changes in functional status in healthy subjects and most patients.

Addition of Impedance Threshold Device Therapy Improves Blood Pressure in the Out-of-Hospital Spontaneously Breathing Hypotensive Patient

An impedance threshold device (ITD) intended for use in spontaneously breathing patients exhibiting low blood pressure. The ITD is reported to provide therapeutic benefit through inspiratory resistance of 7cmH2O, and clinical improvement has been observed as soon as a patient begins to breathe through it. Pre-clinical and clinical studies have shown that the ResQGARD (Advanced Circulatory, Roseville, MN) increases blood pressure during hypotension from a variety of causes. This device has yet to be tested in a large urban out-of-hospital system. This pilot study sought to identify a change in vital signs following paramedic administration of the ITD. Secondary outcomes included patient tolerance and paramedic perception of patient tolerance. A six-month prospective nonrandomized observational cohort study was conducted. All paramedics received 30-45 minutes of training on patient selection and application of the ITD. This initial training was reinforced utilizing a Web-based training video, and a visual reminder (8.5 x 11 laminated sheet) of the study protocol posted inside the ambulance. The cohort was spontaneously breathing adult patients with hypotension due to dehydration, sepsis, anaphylaxis, or hypovolemia. Exclusion criteria included: unable to maintain airway, pulmonary edema, or significant respiratory distress. Upon determination of hypotension (SBP<90mmHG), standard therapy (positioning, reassurance, and intravascular fluids) was initiated and the ITD was applied in accordance with manufacturer's recommendation. The subject was coached to breathe slow and deep utilizing the mask-type device. Supplemental oxygen was supplied if deemed necessary by the paramedic. Vital signs were documented every 2-5 minutes post intervention. Patient tolerance (observed), and patient comfort (reported) were documented. Two hundred subjects were recruited with a mean initial blood pressure 78/50 (± 14/13) heart rate 87 (± 25) beats per minute and ventilatory rate of 19 (± 7) breaths per minute. After paramedic treatment, including ITD mean blood pressure 97/63 (±19/15; p=<.0001) heart rate 87 (± 25; p=.47) beats per minute and ventilatory rate of 19 (± 7; p=.002) breaths per minute, with 66% of blood pressures increased after. Of the 200 hypotensive subjects, 29 were as a result of trauma (fall, auto collisions, shootings/stabbings). The trauma population also demonstrated a significant increase in mean blood pressure from 80 to 103 systolic, and 56 to 71 diastolic (p=<.0001 and .001, respectively), and non-significant change in mean heart rate from 89 to 80 (p=.17). In all groups, 75% of patients reported moderate to easy tolerance, and only 15% of patients reporting difficult tolerance. The ITD was easily assimilated into the standard bundle of care for the treatment of hypotensive patients. A significant increase in blood pressure was observed in the overall cohort. Importantly for the trauma cohort, the ITD did not restore “normal” blood pressure, but continued to allow for permissive hypotension, and continued to be generally well tolerated.

Relation of Target Dose Adherence to One Year Mortality in Heart Failure with Reduced Ejection Fraction: A Substudy of SUGAR

Introduction: Cardiac glycosides are the only available oral agents which have positive inotropic effects and do not increase myocardial oxygen consumption. We conducted a single center study of acute intravenous digoxin loading in patients with low output decompensated heart failure (HF) with hemodynamic monitoring. Hypothesis: Digoxin loading is safe and effective in improving cardiac index (CI) and decreasing the need for IV inotropic support in low output decompensated HF. Methods: A total of 10 patients with low output HF monitored with a Swan Ganz catheter were loaded with 1 mg of Digoxin over a 24 hour period. Loading dose was given intravenously as 0.5 mg followed by 0.25 mg in six hours and then 0.25 mg six hours later. Hemodynamic variables were obtained before and after digoxin loading. Safety end points included atrial and ventricular arrhythmias and digoxin level at 72 hours after loading. Results: Baseline echocardiographic and hemodynamic variables were consistent with advanced HF, with a mean LVEF of 15 +/5 %, a baseline mean CI of 1.67 L/min/m2 and a mean PCWP of 27.4 mm Hg. After Digoxin loading, CI improved by a mean of 60.1 % (0% to 135.7%) and PCWP decreased by 38.2% (11% to 50%). Mean arterial pressure remained stable along with mean heart rate change of -2.1 % (-20. 6 % to +11.4%). Four patients who were IV inotrope dependent were successfully transitioned off IV inotropes to oral agents. None of the patients had any significant atrial or ventricular arrhythmias during the ICU stay. Digoxin levels were consistently below 2 ng/ml at 72 hours post digoxin loading. Conclusions: We demonstrated the efficacy and safety of IV digoxin loading in acutely improving cardiac index and facilitating weaning off IV inotropes in the setting of low output decompensated HF.

The Intersection of Knowledge Transfer and Health Literacy in Reducing Readmission Rates for Heart Failure

Introduction: Cardiac glycosides are the only available oral agents which have positive inotropic effects and do not increase myocardial oxygen consumption. We conducted a single center study of acute intravenous digoxin loading in patients with low output decompensated heart failure (HF) with hemodynamic monitoring. Hypothesis: Digoxin loading is safe and effective in improving cardiac index (CI) and decreasing the need for IV inotropic support in low output decompensated HF. Methods: A total of 10 patients with low output HF monitored with a Swan Ganz catheter were loaded with 1 mg of Digoxin over a 24 hour period. Loading dose was given intravenously as 0.5 mg followed by 0.25 mg in six hours and then 0.25 mg six hours later. Hemodynamic variables were obtained before and after digoxin loading. Safety end points included atrial and ventricular arrhythmias and digoxin level at 72 hours after loading. Results: Baseline echocardiographic and hemodynamic variables were consistent with advanced HF, with a mean LVEF of 15 +/5 %, a baseline mean CI of 1.67 L/min/m2 and a mean PCWP of 27.4 mm Hg. After Digoxin loading, CI improved by a mean of 60.1 % (0% to 135.7%) and PCWP decreased by 38.2% (11% to 50%). Mean arterial pressure remained stable along with mean heart rate change of -2.1 % (-20. 6 % to +11.4%). Four patients who were IV inotrope dependent were successfully transitioned off IV inotropes to oral agents. None of the patients had any significant atrial or ventricular arrhythmias during the ICU stay. Digoxin levels were consistently below 2 ng/ml at 72 hours post digoxin loading. Conclusions: We demonstrated the efficacy and safety of IV digoxin loading in acutely improving cardiac index and facilitating weaning off IV inotropes in the setting of low output decompensated HF.

Heart rate-reducing effects of bisoprolol in Japanese patients with chronic atrial fibrillation: Results of the MAIN-AF study

BackgroundA variety of β-blockers are used to control heart rate (HR) in atrial fibrillation (AF); however, there have been few quantitative assessments of HR and blood pressure reductions with β-blocker monotherapy. Methods and resultsSeventy-eight patients with chronic (persistent or permanent) AF were administered bisoprolol (2.5mg/day) for 2 weeks. Subsequently, 48 patients judged to require a dose increase were either continued on 2.5mg/day (24 patients) or administered a higher dose (5mg/day; 24 patients) in a double-blind fashion for two further weeks. Change in mean HR as determined by Holter electrocardiogram was the primary endpoint. After 2 weeks of bisoprolol 2.5mg/day, mean HR was significantly lower than that before treatment (12.2±9.1beats/min, p<0.001). Mean HRs in the 5-mg and 2.5-mg continuation groups were also significantly decreased compared with those before treatment (17.3±12.9 and 11.4±7.4beats/min, respectively, both p<0.001), with a significant between-group difference (p=0.033). The HR reduction was greater during the day than at night. Although a greater reduction in systolic blood pressure was seen in the 5-mg group than in the 2.5-mg continuation group, the difference between groups was not significant. There were no serious adverse events. ConclusionsThis is the first quantitative analysis of β-blocker monotherapy in AF patients. Bisoprolol exhibits a dose-responsive HR reduction when administered at sequential doses of 2.5mg/day and 5mg/day.

A comparative study of the efficacy of intravenous Paracetamol and Dexmedetomidine on peri-operative hemodynamics and post-operative analgesia for patients undergoing laparoscopic cholecystectomy.

Background:Unrelieved post-operative pain may result in the physical suffering as well as multiple physiological and the psychological consequences, which may adversely affect the peri-operative outcome and contribute to increase the length of stay in hospital.Objectives:We designed this study to evaluate the effect of IV Paracetamol and Dexmedetomidine as multimodal analgesic technique on post-operative analgesia and to reduce the consumption of the systemic opioid and its adverse effects in cases of laparoscopic cholecystectomy.Materials and Methods:Eighty consenting, American society of Anesthesiologist-physical status-I (ASA-PS-I), female patients, aged 19-60 year was randomly assigned to one of the following two groups: Group P (n = 40) received IV 1 g Paracetamol infusion over 10 min pre-operatively and 6 hourly thereafter and Group D (n = 40) received IV Dexmedetomidine 1 μg/kg bolus over 10 min pre-operatively and 0.2-0.4 μg/kg/h thereafter for 24 h. Peri-operative hemodynamic variables, post-operative pain scores, and the need for rescue analgesics were recorded and compared.Results:Profiles of intra-operative hemodynamic changes were similar in both groups in respect to heart rate (HR), diastolic blood pressure, mean arterial pressure except in the systolic blood pressure where Dexmedetomidine significantly reduced it in compare to Paracetamol (P = 0.014). Post-operatively 4th h and 24th h changes in mean HR between two groups was a statistically significant (P < 0.05). Visual analog scale scores were significantly lower in the Group P compared with Group D at 8th, 16th, and 24th h (P < 0.001). Sedation score were statistically higher in the Group D compared with the Group P at post-operative 4th, 8th, 16th, and 24th h (P < 0.006).Conclusion:Adjunctive use of both Paracetamol and Dexmedetomidine infusion reduced opioid use. However, Paracetamol peri-operatively provides adequate analgesia with the less sedation whereas Dexmedetomidine provides analgesia and co-operative sedation.

Hemodynamic Changes during Otolaryngological Office-Based Flexible Endoscopic Procedures

A preponderance of literature supports the safety of office-based flexible endoscopic procedures of the upper aerodigestive tract; however, until recently there were no data regarding hemodynamic stability during these procedures. A recent study showed intraprocedure changes in patients' hemodynamic parameters, raising the concern that perhaps patients should be monitored during these procedures. The aim of our study was to determine whether physiologically significant alterations in vital signs occur during office-based flexible endoscopic procedures. We performed a retrospective review of 100 consecutive patients who underwent office-based flexible endoscopic procedures of the upper aerodigestive tract from July 2010 to October 2011. Baseline values and the maximal changes in systolic blood pressure, diastolic blood pressure, heart rate, and oxygen saturation were recorded and compared. One hundred consecutive patients were included in the study. Twenty-one patients (21%) had severe hypertension and 40 patients (40%) had tachycardia during the procedure. The mean change overall in systolic blood pressure was 26.2 mm Hg (p < 0.001), the mean change in diastolic blood pressure was 13.9 mm Hg (p < 0.001), the mean change in heart rate was 16.6 beats per minute (p < 0.001), and the mean change in oxygen saturation was 1.6% (p < 0.001). These changes were significant. On further breakdown into groups, patients over 50 years of age and patients who were undergoing esophageal or laser procedures had significant elevations in heart rate (p = 0.01 and p = 0.04, respectively). An elevation in diastolic blood pressure was also significant in patients who were undergoing esophageal or laser procedures (p = 0.04 for both). These data concur with those of the previous report that found potentially significant hemodynamic changes during office-based procedures. Although preliminary, our findings suggest that it may be wise to monitor vital signs in patients over 50 years of age and patients who are undergoing an esophageal or laser procedure who are at risk for complications that could arise from tachycardia and hypertension.

Cardiovascular Effects and Safety of Fingolimod in Clinical Practice (P04.138)

Objective: To describe the cardiovascular safety and tolerability of fingolimod in a clinical/academic practice. Background Fingolimod is approved by the FDA for relapsing multiple sclerosis (RRMS). Bradycardia and slowing of AV conduction were observed with fingolimod initiation in clinical trials. Screening electrocardiogram (EKG) and a first dose observation (FDO) period is recommended in all patients starting this medication. Design/Methods: Patients starting fingolimod from December 2010 to August 2011 were identified through the electronic medical record database. Demographics, cardiovascular history, screening EKG, cardiology consultation notes, FDO experience and 3 month follow-up data were retrieved and tabulated. Results: A total of 318 patients were identified. A history of hypertension was present in 30 (9.4%) of patients and a history of cardiac disease was present in 8 (2.5%) patients. Betablockers, calcium channel blockers, and digoxin were used by 3.7%, 2.8%, and 0.6% of patients respectively. Pretreatment EKG studies were available in 300 (94.3%) patients and were abnormal in 80 (25.2%) cases. Cardiology consultation was requested in 33 (10.4%) patients and use of fingolimod was cleared for all. During FDO mean heart rate change was -11.5 bpm (p Conclusions: Screening EKG showed abnormalities in a quarter of patients starting fingolimod, and identified patients at risk for symptomatic bradycardia. Fingolimod was well tolerated and no severe or serious cardiovascular adverse effects were encountered during FDO. Disclosure: Dr. Bermel has received personal compensation for activities with Astellas, Biogen Idec, Novartis, and Teva Neuroscience as a consultant and/or speaker. Dr. Ontaneda has nothing to disclose. Dr. Hara-Cleaver has received personal compensation for activities with Biogen Idec, Novartis, Serono, Inc., and TEVA Neuroscience as a consultant. Dr. Rudick has received personal compensation for activities with Biogen Idec, Genzyme, and Wyeth/Pfizer. Dr. Rudick has received research support from Biogen Idec through the Cleveland Clinic. Dr. Cohen has received personal compensation for activities with Biogen Idec, Eli Lilly & Company, Novartis, and Vaccinex. Dr. Cohen has received research support for activities with Biogen Idec, BioMS, Genzyme Corporation, Novartis, Synthon, and Teva Neuroscience.

Heart rate stability and decreased parasympathetic heart rate variability in healthy young adults during perceived stress

We report in healthy and fit university students that stressful university examination conditions are associated with depressed parasympathetic activity (as reflected in heart rate variability (HRV) parameters). We discuss these findings and possible theoretical reasons for why a perceived stressful situation may impart HRV changes but not changes in mean heart rate (HR).

Multicenter Comparison of High Concentration Contrast Agent Iomeprol-400 With Iso-osmolar Iodixanol-320

To compare a contrast agent with high iodine concentration with an iso-osmolar contrast agent for coronary dual-source computed tomography angiography (DS-CTA), and to assess whether the contrast agent characteristics may affect the diagnostic quality of coronary DS-CTA. Patients were randomized to receive either 80 mL of iodixa:nol-320 (Visipaque, GE Healthcare, Chalfont St. Giles, United Kingdom) or iomeprol-400 (Iomeron, Bracco Imaging SpA, Milan, Italy) at 5 mL/s. Mean, minimum, maximum heart rate, and its variation (max-min) were assessed during calcium scoring scan and coronary DS-CTA. Three off-site readers independently evaluated the image sets in terms of technical adequacy, reasons for inadequacy, vessel visualization, diagnostic confidence (based on a 5-point scale), and arterial contrast opacification in Hounsfield units (HUs). Ninety-six patients were included in the final evaluation. No significant differences were observed for pre- and postdose heart rate values for iomeron-400 compared with iodixanol-320, and changes in heart rate variation were also not significantly different (-2.3 ± 11.7 vs. -2.5 ± 7.3 bpm, P > 0.1). Contrast measurements in all analyzed vessels were significantly higher for iomeprol-400 (mean, 391.5-441.4 HU) compared with iodixanol-320 (mean, 332.3-365.5 HU, all P ≤ 0.0038). There was no significant difference in qualitative visualization of coronary arteries (mean scores, 4.3-4.5 for iomeprol, 4.1-4.3 for iodixanol, P = 0.15-0.28), or in diagnostic confidence scores. HU were inversely correlated with the number of insufficiently opacified segments (all readers P ≤ 0.0006). The high-iodine concentration contrast medium iomeprol-400 demonstrated significant benefit for coronary arterial enhancement compared with the iso-osmolar contrast medium iodixanol-320 when administered at identical flow rates and volumes for coronary DS-CTA. In addition, higher enhancement levels were found to be associated with lower numbers of inadequately visualized segments. Finally, observed mean heart rate changes after intravenous contrast injection were generally small during the examination and comparable for both agents.

Heart Rates of Elementary Physical Education Students During the Dancing Classrooms Program

We examined how different types of dance activities, along with their duration, influenced heart rate responses among fifth-grade physical education students (N = 96) who participated in the Dancing Classrooms program. Results indicated that the overall Dancing Classrooms program elicits a moderate cardiovascular heart rate response (M = 124.4 bpm), in which 47% of class time was spent above a 60% maximal heart rate threshold. The swing dance in particular (M = 143.4 bpm) stimulated a much higher heart rate level than all other dances in the program, with a mean heart rate change of 52.6 bpm. Girls (127.3 bpm) achieved marginally higher heart rates (p = .059) than boys (121.1 bpm).

Normal cardiac autonomic regulation during submaximal, but not maximal, cycle ergometry exercise in persons with Down syndrome

Objective To compare heart rate variability (HRV) responses to submaximal cycle ergometry exercise between persons with and without DS when matched for heart rate (HR) changes to that stressor. METHODS Persons with and without DS (n=9/grp; 28 yrs) were matched for HR responses during a 6 min cycle ergometry task (avg cycle HR-baseline HR) performed at 50% of body weight in Watts. HRV was assessed in the frequency domain (total power, low frequency (LF) and high frequency HF)). Blood pressure was obtained using finger photoplethysmography. RESULTS The mean change in HR was 29 ± 10 bpm. Both groups exhibited similar responses to the cycle exercise, with no differences between groups in any of the HRV measures. Systolic blood pressure was different between groups (p<0.05), but changed similarly with exercise. Peak aerobic capacity (DS vs. Control: 24.2 vs. 36.7 mL/kg/min), HR (167 vs. 189 bpm), and catecholamine levels (epinephrine: 55 vs. 314 pg/mL) were lower with maximal exercise in those with DS vs. controls (p<0.05). CONCLUSIONS While persons with DS exhibit attenuated work capacity and peak HR, it appears that a subset of individuals do have normal cardiac autonomic regulation at submaximal exercise loads. Supported in part by an American Heart Association Grant-in-Aid DS Controls Rest Cycle Rest Cycle Systolic BP (mm Hg)* 110 ± 7 137 ± 20 136 ± 21 159 ± 26 Total power (ms2) 2175 ± 495 774 ± 146 3233 ± 526 555 ± 155 Low Frequency (ms2) 972 ± 284 127 ± 46 1678 ± 284 163 ± 45 High Frequency (ms2) 252 ± 105 73 ± 27 343 ± 106 49 ± 27

Anesthesia Literature Review

Anesthesia Literature Review

Stuttered and fluent speakers' heart rate and skin conductance in response to fluent and stuttered speech

Previous studies have found simultaneous increases in skin conductance response and decreases in heart rate when normally fluent speakers watched and listened to stuttered speech compared with fluent speech, suggesting that stuttering induces arousal and emotional unpleasantness in listeners. However, physiological responses of persons who stutter observing stuttering and fluent speech has not been measured. Research suggests that the mechanism responsible for listeners' reactions is the mirror neuron system. The mirror neuron system activates when perceiving and producing goal-directed actions and forms the link between action perception and action production. To compare physiological responses elicited via fluent and stuttered speech in fluent and persons who stutter groups. Participants included 15 adult persons who stutter (mean age = 29.7 years) and 21 normally fluent controls (mean age = 23.7 years). Participants watched and listened to six speech samples read by three persons who stutter speakers and three fluent speakers, while their skin conductance response and heart rate were recorded simultaneously. Participants' responses to each speech sample were defined as changes in mean heart rate and mean skin conductance response between 15 s before and 15 s during stimuli presentation. Both groups showed similar patterns of response: skin conductance response was significantly increased and heart rate was significantly decreased in response to stuttered versus fluent speech. Similar to previous findings, the highest skin conductance response measures were induced by the first presentation of stuttered speech, with the response attenuating on subsequent presentations, while the heart rate was stable over time. Results confirmed past research that showed arousal and emotional unpleasantness when observing stuttering. Clinically, these results acknowledge the arousal and emotional discomfort in fluent speakers and persons who stutter. The physiological responses to stuttering and the underlying emotional aspects should be discussed in the therapeutic milieu with notions about coping strategies.

The Effect of office-based flexible endoscopic surgery on hemodynamic stability123

Because of technological advances in endoscopy equipment, office-based flexible endoscopic surgery (OBFES) is becoming more widespread and common in practice. In our experience, we have noticed that patients often have marked rises in heart rate (HR) and blood pressure (BP). However, to our knowledge, changes in hemodynamic stability during these procedures have never been studied. The primary aim of this study was to investigate changes in BP, HR, and oxygen (O(2)) saturation in patients undergoing unsedated laryngeal surgery. Retrospective chart review. Medical records for 31 consecutive subjects who underwent OBFES at the University of California, San Francisco Mt. Zion Endoscopy Suite from June 2008 to June 2009 were reviewed. Absolute values and changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), HR, and O(2) saturation from baseline were evaluated. During the procedure, 9/31 patients had tachycardia (29%) and 7/31 had severe hypertension (23%). The mean change in HR was 14.6 beats/min (P < .0001), mean change in DBP was 18.5 mm of mercury (Hg) (P < .0001), mean change in SBP was 33.1 (P < .0001), and mean change in O(2) was 0.8 (P = .01). Older age groups had significantly higher baseline DBP (P = .02) and SBP (P = .0006), as well as procedural SBP (P = .0007). One procedure was terminated early secondary to unsafe rises in SBP and DBP. Change in DBP and SBP was not correlated with age. Significant changes in hemodynamic status occur during OBFES. Clinicians should be aware of this and consider the risks these changes may pose to their patients. Monitoring during these procedures may be indicated.

Evaluating the Use of Dexmedetomidine in Neurocritical Care Patients

Dexmedetomidine is a highly selective alpha(2)-adrenoreceptor agonist that produces dose-dependent sedation, anxiolysis, and analgesia without respiratory depression. Dexmedetomidine has been used in critically ill medical, surgical, and pediatric patients, as an adjunct to sedation and/or for treating drug or alcohol withdrawal. Information regarding the dosing and utilization of dexmedetomidine has been derived primarily from studies in critically ill patients in the medical intensive care unit. There has been no study designed specifically to evaluate dexmedetomidine for these therapeutic uses in the neurocritical care population. The primary and secondary objectives were to evaluate the starting dose of dexmedetomidine for neurocritical care patients and to assess the effect on hemodynamic parameters, respectively. This was a prospective, observational study conducted from October 2007 to March 2008. Patients were included if they were admitted to the Neuro-Intensive Care Unit and received dexmedetomidine infusion. Six patients met the criteria for the study. The mean initial dexmedetomidine infusion rate and mean maximum infusion rate were 0.67 +/- 0.2 and 1.3 +/- 0.5 mcg/kg/h, respectively. The mean duration of dexmedetomidine infusion was 66 +/- 10 h. Two patients (33%) experienced a significant change in mean heart rate and systolic blood pressure after starting dexmedetomidine infusion. Neurocritically ill patients may require high doses of dexmedetomidine to achieve desired levels of sedation. The high rates and long duration of dexmedetomidine infusion had a statistically, but not clinically, significant impact on hemodynamic parameters.

One Hundred–Foot Walk Test for Functional Assessment of Clinic Patients

BackgroundGait velocity measurements provide functional assessment of patients with diverse diseases and allow predictions about future adverse events. The optimal distance for patient classification is uncertain. MethodsParticipants were identified in internal medicine clinics and had to be independently ambulatory. Study investigators collected medical information, used a qualitative test to assess gait and balance (G and B score), and measured gait velocity with a timed 100-foot walk. ResultsOne hundred eighty-four patients participated in this study. The mean age was 57.8±12.7years; 50% of the participants were men. The mean gait speed was 3.33±0.71 ft/sec. Gait speed decreased with age and with body mass index (BMI) and increased with height and male sex. Patients with more comorbidities had decreased speed (P<0.01). There were significant correlations between gait speed and grip strength (P<0.01) and between lower G and B scores and slower gait speeds (P<0.01). G and B scores were negatively correlated with age, BMI, and certain diagnoses. They also predicted risk for past falls. The mean heart rate change during the test was 8 beats per minute. Patients in the highest quartile for heart rate change had lower gait speeds than patients in the other 3 quartiles, suggesting physiologic impairment. ConclusionsA 100-foot walk test in clinic patients provides a practical functional assessment. Gait speed was slower in patients with multiple comorbidities and poor balance. Patients with increased heart rate responses during this test seem to have physiologic impairment. This test has the potential to predict adverse events and to quantitatively determine responses to therapeutic interventions but needs prospective evaluation in clinical studies.

Increased non-stationarity of heart rate during general anaesthesia with sevoflurane or desflurane in children

BackgroundDuring general anaesthesia, the most prominent change in heart rate variability (HRV) is a decrease in the magnitude of heart rate (HR) oscillation in the high- and low-frequency ranges. In children receiving sevoflurane or desflurane, we observed a significant increase in HR non-stationarity, that is, a significant change of mean HR over time. The aim of our study was to describe this increased non-stationarity and compare it with the decrease in the magnitude of HR oscillation. MethodsSixty children received sevoflurane (n=30) or desflurane anaesthesia (n=30). The magnitude of HR oscillation and non-stationarity during pre-anaesthesia and anaesthesia were measured by spectral and Hurst analyses using structure function, respectively. ResultsLow- and high-frequency powers decreased significantly and the very-short-term (2≤τ≤8 s, Hα) and short-term Hurst exponent (8≤τ≤45 s, Hβ) increased significantly during the anaesthetic period compared with the pre-anaesthetic period, regardless of the anaesthetic agent [sevoflurane: mean (sd) Hα 0.414 (0.169) vs 0.252 (0.0655), Hβ 0.481 (0.169) vs 0.078 (0.0409); desflurane Hα 0.336 (0.171) vs 0.261 (0.0614), Hβ 0.471 (0.221) vs 0.0813 (0.049)]. Stepwise discriminant analysis showed that the short-term Hurst exponent was better than the spectral indices at differentiating between the pre-anaesthetic period and anaesthetic period. ConclusionsDuring sevoflurane and desflurane anaesthesia in children, there is a significant increase in very-short-term and short-term HR non-stationarity. Furthermore, the greater short-term non-stationarity differentiates better between the pre-anaesthesia and anaesthesia than the decreased magnitude of HR oscillation in the high- and low-frequency ranges.