Lower Mean Heart Rate Research Articles

Heart rate variability in sick sinus syndrome: does it have a diagnostic role?

Hypothesis of our study was that the irregular rhythm of sick sinus syndrome (SSS) was characterized by an augmented HRV. Objective was to assess whether SSS patients had a typical HRV profile. We screened all 1947 consecutive Holter ECGs performed in our Units of Vascular Medicine and Internal Medicine and Cardioangiology at the University of Palermo (Italy) from April 2010 to September 2014. Among these, we selected 30 patients with ECG criteria of SSS. They were compared to 30 patients without SSS matched for age, sex and comorbidities. The SSS group had a lower mean heart rate (HR) (P=0.003), and a longer mean NN max-min longer (P<0.0005) compared to control group. SSS group had higher mean pNN50 (P=0.043), mean RMSSD (P=0.006), mean SDNN (P=0.021), and mean SDNNi (P=0.005) as compared with control group. Moreover, HR ≤64.5 bpm, NN max-min>1355 msec, pNN50>16.08, RMSSD>50.2, SDNN>151.94, and SDNNi>71.1 showed a predictive value for diagnosis of SSS. The positivity of all 6 variables according to the aforementioned cut-offs ensured a positive predictive value of 100% and the negativity of all 6 variables had a negative predictive value of 94% for diagnosis of SSS. Among SSS patients, we did not observe any correlation between HR and HRV variables. SSS patients have a HRV profile characterized by: low HR, long NN max-min interval, and elevated pNN50, RMSSD, SDNN and SDNNi values with specific diagnostic cut-offs for diagnosis of SSS. Moreover, we found the absence of correlation between HR and all time-domain HRV variables in SSS patients.

Rate-responsive pacing and atrial high rate episodes in cardiac resynchronization therapy patients: Is low heart rate the key?

BackgroundThe role of atrial rate‐responsive (RR) pacing in cardiac resynchronization therapy (CRT) is unclear due to the favorable effect of rate lowering in systolic heart failure. Atrial high rate episodes (AHREs) in CRT recipients are particularly worrisome since they cause loss of CRT, beyond representing a stroke risk factor.HypothesisThe presence of an association between RR and the incidence of AHREs.MethodsDaily remote transmissions from 836 CRT recipients were analyzed. AHREs were classified by duration: ≥15 minutes, ≥5 hours, and ≥ 24 hours. Variables possibly associated to AHREs were included in time‐dependent proportional‐hazard models, averaging over 30‐day periods and adjusting for main baseline variables.ResultsAfter a median follow‐up of 23.9 (12.2‐36.0) months, 507 (60.6%) patients experienced at least one 15‐minute AHRE. RR function was programmed in 166 (19.8%) patients and was associated with an increased AHRE occurrence rate with hazard ratio (HR) ranging from 1.45 to 1.78 for the 3 cutoffs of episode duration. The negative effect of RR function was not observed in the subset of patients with low mean heart rate (<68 bpm). Higher mean heart rates increased AHRE risk (HR:1.02, P = .01), while CRT amount decreased it (HR:0.98, P < .01). The extent of atrial pacing did not predict AHRE occurrence.ConclusionsRR pacing in CRT recipients is associated with increased AHRE occurrence, especially when an average heart rate > 68 bpm is attained.

A comparative study of midazolam alone or in combination with dexmedetomidine or clonidine for awake fiberoptic intubation

Background:Awake fiberoptic intubation (AFOI) is the gold standard technique for managing patients with anticipated difficult airway. Conscious sedation is desirable, not only to make the procedure more tolerable and comfortable for the patient but also to ensure optimal intubating conditions. Ideal sedation regime for AFOI should provide comfort, cooperation, hemodynamic stability, and amnesia along with maintenance of spontaneous respiration. Several sedative agents have been assessed over the past two decades for this purpose but α2 agonists appear to be the favorable choice owing to its sedative, analgesic, amnestic, and sympatholytic properties along with good hemodynamic profile.Aims:The present study has been aimed to recognize the characteristics of dexmedetomidine, clonidine, and midazolam and to compare their efficacy in providing optimal intubating conditions as well as hemodynamic stability during AFOI.Settings and Design:A prospective double-blind randomized study done in tertiary care hospital.Materials and Methods:Sixty patients of American Society of Anesthesiologists physical status Classes I and II aged 18–60 years with anticipated difficult airway were randomly allocated into three groups. All the patients received injection midazolam bolus followed by sedation infusion of midazolam, dexmedetomidine, and clonidine according to the allocated group. Primary outcome includes the time to achieve Ramsay Sedation Score (RSS) ≥2, time taken in intubation, intubation score, comfort score for fiberoptic insertion and intubation, and patient tolerance after intubation. The secondary outcome was hemodynamic, and respiratory variables include changes in heart rate (HR), mean arterial pressure (MAP), oxygen saturation (SpO2), and respiratory rate during the procedure.Statistical Analysis:All data were recorded, summarized, tabulated, and statistically analyzed using SPSS 16.0 version (Chicago, Inc., USA). The data were presented in mean ± standard deviation. P < 0.05 was considered as statistically significant.Results:All the three groups were comparable in terms of demographic profile. Time to achieve RSS ≥2 and mean intubation time was significantly less in Groups D and C as compared to Group M (P < 0.001). Among groups, Group D took least time to achieve RSS ≥2 (5.53 ± 0.74) and mean intubation time (4.53 ± 0.91). Similarly, overall intubation score, comfort, and patient tolerance score were significantly more in Group M as compared to Groups D and C (P < 0.001). Among the groups, Group D achieved least intubation score (3.80 ± 0.67) and comfort score (2.53 ± 0.74). Although Groups D and C have a lower mean HR and MAP during the procedure and intubation compared to Group M, the incidence of SpO2 is most frequent with clonidine.Conclusions:Patients who received α2 agonist were calmer and cooperative with less pain and discomfort than the patients who received midazolam. Dexmedetomidine allows better endurance, stable hemodynamics, and patent airway as compared to clonidine.

Physiological and affective responses of 30s‒30s intermittent small-sided game in elite handball players: A new alternative to intermittent running

Objectives: To compare physiological and affective demands of a novel small-sided game designed in intermittent (30s‒30s) regimen opposing 3-a-side field players with 30s‒30s shuttle running and handball match play. Methods: Fourteen elite male handball players (age 23.8 ± 4.4 y; body mass 84.0 ± 7.4 kg; height 188 ± 0.06 m) performed 2 periods of 10-min of each experimental exercise in separate occasions. Physiological demand was assessed using mean heart rate, time spent in heart rate intensity zones and post-exercise blood lactate concentration. The difference between ‘perceived exertion’ and ‘pleasure’ determined the affective balance. Results: Small-sided game and shuttle running drills showed similar mean heart rate (88.8 ±2.4 and 90.4 ±2.8 % of peak heart rate, respectively) and time spent in heart rate zones. The match play elicited lower mean heart rate (86.9 ± 3.4 % of peak heart rate, P ≤ 0.05, large ES) than small-sided game and shuttle running. Peak lactate for small-sided game (6.6 ±2.6 mmol/L) was lower than shuttle running (10 ±2.2 mmol/L, P ≤ 0.05, large ES) whereas no significant difference was observed with match play. The small-sided game showed lower affective balance than shuttle running (P ≤ 0.01, large ES). Conclusions: Coaches can be confident in prescribing the small-sided game as a suitable alternative to shuttle running to provide consistent aerobic stimulus with lower affective balance. The small-sided game may be considered as a specific training method in achieving relevant physiological adaptations for handball match play.

A17369 Application of Continuous Noninvasive Arterial Pressure Monitor in Patients with Cardiovascular Diseases plus Obstructive Sleep Apnea

Objectives: The hemodynamics of patient with cardiovascular diseases (CVD) plus obstructive sleep apnea (OSA) is changeable and complicated. A new continuous noninvasive arterial pressure monitor (CNAP) has been validated in screening the hemodynamics. The aim of our study is to assess the performance of CNAP in patients with CVD plus OSA. Methods: The hemodynamics of patient with cardiovascular diseases (CVD) plus obstructive sleep apnea (OSA) is changeable and complicated. A new continuous noninvasive arterial pressure monitor (CNAP) has been validated in screening the hemodynamics. The aim of our study is to assess the performance of CNAP in patients with CVD plus OSA. Results: Compared with the values monitored before sleeping, patients had higher mean systolic blood pressure (125.60 ± 17.19mmHg vs. 118.96 ± 17.97mmHg, P < 0.05), lower mean heart rate (66.41 ± 9.19bpm vs. 69.61 ± 12.57bpm, P < 0.05) during sleep apnea events. 10 patients have used continuous positive airway pressure (CPAP) to treat OSA. Compared with the values monitored before treatment by CPAP, patients using CPAP had lower cardiac output (5.41 ± 1.12l/min vs. 5.74 ± 1.19l/min, P < 0.05), cardiac index (2.85 ± 0.40l/min/m^2 vs. 3.02 ± 0.4l/min/m^2, P < 0.05), pulse pressure variation (5.67 ± 1.20% vs. 6.48 ± 1.20%, P < 0.05) and stroke volume variation (7.47 ± 1.60% vs. 11.03 ± 2.78%, P < 0.05). Conclusion: CNAP could be clinically useful to assess hemodynamics of patient with CVD plus OSA. When sleep apnea events happened, patients’ mean systolic blood pressure became higher while mean heart rate became lower. When patients using CPAP, cardiac output, cardiac index, pulse pressure variation and stroke volume variation all became lower.

The multiple implications of dipper profiles in hypertensive diabetics patients: The better cardiovascular prognostic of those with lowest mean heart rate

The multiple implications of dipper profiles in hypertensive diabetics patients: The better cardiovascular prognostic of those with lowest mean heart rate

Prefrontal cortex modulates the correlations between brain-derived neurotrophic factor level, serotonin, and the autonomic nervous system

Top-down regulation in the human brain and anatomical connections between the prefrontal cortex (PFC) and specific catecholamine-related regions have been well-studied. However, the way in which the PFC modulates downstream neuro-networks in terms of serotonin and the autonomic nervous system (ANS) by variation in the level of brain-derived neurotrophic factor (BDNF) is still unclear. We recruited sixty-seven healthy subjects. Serotonin transporter (SERT) availability was examined by SPECT with [123I]ADAM analysis; heart rate variability (HRV) testing was performed, and the BDNF level was measured. The Wisconsin card-sorting test (WCST), which assesses PFC activation, was also conducted. The interactions of BDNF level and SERT availability were significant in relation to the HRV indexes of low frequency, high frequency, total power, and mean heart rate range. Moderate to significant positive correlations between SERT availability and the above-mentioned HRV indexes existed only in subjects with a low BDNF level. Furthermore, in the low BDNF level group, only those with high WCST perseveration errors or low category completions exhibited significant positive correlations between SERT availability and HRV indexes. A lower BDNF level and poorer PFC function might modulate the synergistic effects of serotonergic and ANS systems in order to maintain brain physiological and psychological homeostasis.

Severe conduction defects requiring permanent pacemaker implantation in patients with a new-onset left bundle branch block after transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is frequently associated with cardiac conduction defects (CCD) requiring permanent pacemaker implantation (PPI). Although new-onset left bundle branch block (LBBB) is often seen, the rate of progression to severe CCD is unclear. We aimed to find clinical and electrocardiographic (ECG) parameters associated with severe CCD requiring PPI in patients with a new-onset LBBB after TAVI and assess its effect on clinical outcome. All consecutive patients undergoing TAVI who developed a new-onset LBBB were retrospectively analysed. We excluded patients with pre-existing bundle branch block or pacemaker. Patients were divided into two groups: with or without PPI after TAVI. We included 155 patients (50% female, 80 ± 7 years), of which 37 (24%) developed CCD requiring PPI, mainly due to a total atrioventricular block (n = 17; 46%). Cardiac conduction defects requiring PPI were associated with the following pre-existing parameters: atrial fibrillation (AF), the use of digoxin, CoreValve implantation, and left heart axis. Furthermore, it was associated with the following post-procedural parameters: left heart axis, lower mean heart rate, and prolonged PQ and QRS times. During follow-up, patients with PPI showed a lower mortality rate (11 vs. 29%, P = 0.03). In patients without PPI, mortality was lower in those with narrower QRS complex and transient LBBB. The severity and persistence of a new-onset LBBB after TAVI is associated with mortality. Cardiac conduction defects requiring PPI are associated with prior AF, the use of digoxin, CoreValve implantation, and a left heart axis. In these patients, PPI portends a better prognosis than no PPI.

Electrocardiograms of Children and Adolescents Practicing Non-competitive Sports: Normal Limits and Abnormal Findings in a Large European Cohort Evaluated by Telecardiology.

The objective of this study was to derive normal electrocardiographic values and to report the abnormal findings in a large contemporary European cohort of physically active children and young adolescents. In a 3-month period, data derived from subjects aged between 3 and 14years and referred to the Telecardiology Centre (Genoa, Italy) for electrocardiogram (ECG) evaluation as pre-participation screening for non-competitive sports were analyzed. A total of 2060 ECGs were recorded. Of those, 1962 did not show any morphological abnormality and were used to derive normality ranges for heart rate, PR interval, QRS duration, corrected QT interval, and voltage of R wave as measured in V1 according to age and sex. Findings and clinical implications of the 98 ECGs with abnormal findings were also reported. Abnormal ECG findings were not as uncommon as expected in this population, being manifest in about 5% of subjects. However, major ECG anomalies (diffuse negative T-waves, pre-excitation) were present in just ten subjects (0.5%). Lower mean heart rate values (from 90-100 bpm at 3years of age to 80-85 bpm at 14years of age) and lower rates of the prevalence of negative T-waves in the V3 lead (from 55-60% at 3years of age to 8-10% at 14years of age) were observed with increasing age. This is the first work reporting derived normal limits and abnormal ECG findings in a large contemporary European cohort of children and adolescents aged 3-14years practicing non-competitive sports. Clear pathological alterations are extremely uncommon, deserving, when encountered, additional examinations. Even in a physically active population, the common features of an adult athlete's ECG are absent.

호흡 시 호기 및 흡기 비율과 자세가 체질별 심박변이도에 미치는 영향

Objectives We observed what effects both ratio of inhalation and exhalation(I/E) and posture have on heart rate variability(HRV) according to Sasang Constitution(SC).Methods HRV of 73 healthy participants who filled in self-questionnaires was recorded while they carried out 0.1Hz paced breathing(PB) with sitting, usual breathing(UB) with standing, and 0.1Hz PB with standing. PB was conducted to 4:6 or 6:4 of I/E and UB with sitting was executed before and after each breathing. Finally, HRV indices were analyzed of 60 participants(Soeum: 24, Soyang: 18, Taeeum: 18).Results & Conclusions In both self-questionnaires and HRV indices, there are not statistically significant between SC about the posture and I/E. SOEUM preferred 4:6 of I/E and showed lower mean RR and SDNN. SOYANG preferred 6:4 of I/E and showed higher mean RR and lower mean heart rate. TAEUM did not prefer I/E and showed the highest SDNN.

The aging influence on cardiorespiratory, metabolic, and energy expenditure adaptations in head-out aquatic exercises: Differences between young and elderly women

ABSTRACTThe purpose of this study was to: (1) establish the relationship between acute physiological responses and musical cadence; and (2) compare physiologic responses between young and older women. Eighteen older (mean = 65.06 ± 5.77 years) and 19 young (mean = 22.16 ± 2.63 years) women underwent an intermittent and progressive protocol performing the head-out aquatic exercise the “rocking horse.” Results showed that older women demonstrated lower mean heart rate, blood lactate concentration (bLa), and oxygen uptake (VO2) at rest. Hierarchical linear modeling showed that variations in the rating of perceived effort and individual metabolic equivalent of task did not differ significantly by age group. However, during exercise, physiological responses of younger women were significantly different than for older women: in mean values, for each increased musical beat per minute, mean bLa was 0.003 mmol/l, VO2 was 0.024 ml/kg/min, and energy expenditure was 0.0001 kcal/kg/min higher for younger women. This study shows that increases in musical cadence increased the cardiorespiratory, metabolic, and energy expenditure responses. However, these responses during increasing intensity seemed to differ between young and older women, with lower values for the elderly group, when performing head-out aquatic exercises.

Effects of Cold Water Immersion on Muscle Oxygenation During Repeated Bouts of Fatiguing Exercise: A Randomized Controlled Study.

Postexercise cold water immersion has been advocated to athletes as a means of accelerating recovery and improving performance. Given the effects of cold water immersion on blood flow, evaluating in vivo changes in tissue oxygenation during cold water immersion may help further our understanding of this recovery modality. This study aimed to investigate the effects of cold water immersion on muscle oxygenation and performance during repeated bouts of fatiguing exercise in a group of healthy young adults.Twenty healthy subjects performed 2 fatiguing bouts of maximal dynamic knee extension and flexion contractions both concentrically on an isokinetic dynamometer with a 10-min recovery period in between. Subjects were randomly assigned to either a cold water immersion (treatment) or passive recovery (control) group. Changes in muscle oxygenation were monitored continuously using near-infrared spectroscopy. Muscle performance was measured with isokinetic dynamometry during each fatiguing bout. Skin temperature, heart rate, blood pressure, and muscle soreness ratings were also assessed. Repeated measures ANOVA analysis was used to evaluate treatment effects.The treatment group had a significantly lower mean heart rate and lower skin temperature compared to the control group (P < 0.05). Cold water immersion attenuated a reduction in tissue oxygenation in the second fatiguing bout by 4% when compared with control. Muscle soreness was rated lower 1 day post-testing (P < 0.05). However, cold water immersion had no significant effect on muscle performance in subsequent exercise.As the results show that cold water immersion attenuated decreased tissue oxygenation in subsequent exercise performance, the metabolic response to exercise after cold water immersion is worthy of further exploration.

HEART RATE MONITORING SYSTEMS IN GROUPS FOR RELIABILITY AND VALIDITY ASSESSMENT OF CARDIORESPIRATORY FITNESS ANALYSIS

According to statistics in Taiwan, the proportion of students engaged in regular exercise has declined drastically with the increase in education level. This study thus aims to provide a platform for monitoring of group cardiorespiratory fitness to allow users such as teachers or coaches to easily monitor a group’s exercise condition, intensity and duration to increase exercise efficiency, promote exercise motivation and reduce exercise risk. Based on group measurement concept and wearable chest strap textiles integrated with heart rate monitoring devices, teachers or coaches can immediately acquire and display all heart rate information on a notebook computer together with synchronous field projection display. The acquired heart rate data can also be automatically recorded and analyzed to assist in assessing the physical fitness. Our proposed platform aims to monitor the cardiorespiratory fitness in group mainly for college students and young office worker. To validate the stability of our platform in the long term, we recruited the college students in a physical fitness class, 35 in total, as the subjects for long term observation. In the experiments the subjects are divided into “varsity group” and “sedentary group” according to whether they are with or without regular exercise habits. Subjects wearing chest straps were instructed to take the 3-minute Step Test and the 5-minute constant intensity exercise test. The results show that the “varsity group” has a lower resting heart rate ([Formula: see text][Formula: see text]bpm vs. [Formula: see text][Formula: see text]bpm), a lower exercise heart rate ([Formula: see text][Formula: see text]bpm vs. [Formula: see text][Formula: see text]bpm) and a lower mean heart rate ([Formula: see text][Formula: see text]bpm vs. [Formula: see text][Formula: see text]bpm). The “Varsity group” also has a higher heart rate recovery percentage at the first minute ([Formula: see text] vs. [Formula: see text]) and the second minute ([Formula: see text] vs. [Formula: see text]). Moreover, all these indexes have a high correlation with the fitness index in the 3-minute Step Test, among which the percentage of heart rate recovery in the first minute shows the highest positive correlation ([Formula: see text], [Formula: see text]). Our wearable heart rate monitoring system can thus be deemed as effective to provide a platform for measurement of group heart rates and for assessment of cardiorespiratory fitness.

Low resting heart rates are associated with new-onset atrial fibrillation in patients with vascular disease: results of the ONTARGET/TRANSCEND studies.

Elevated systolic blood pressure (SBP) and high resting heart rate (HR) are associated with cardiovascular end-points. Although the association between atrial fibrillation (AF) and SBP is well established, the relation between AF and HR remains unclear. In patients from the ONTARGET and TRANSCEND studies with high cardiovascular disease risk (n=27064), new-onset AF was evaluated in relation to mean SBP, visit-to-visit variation in SBP (SBP-CV; i.e. SD/mean×100%), mean HR and visit-to-visit variation in HR (HR-CV). Low mean HR (P<0.0001) and high SBP (P=0.0021) were associated with incident AF. High SBP-CV (P=0.031) and HR-CV (P<0.0001) were also associated with incident AF. After adjustment for confounders, SBP and SBP-CV were no longer significantly associated with AF. The detrimental effect of low HR was particularly evident in subjects who were not receiving treatment with beta-blockers (P=0.014 for interaction between beta-blocker use and mean HR). In addition to low HR, high HR-CV and high SBP had additive effects on incident AF. Low mean HR (<60 beatsmin(-1) ) is independently associated with incident AF, and low HR-CV and high SBP further increase the incidence of new-onset AF in patients at high risk of cardiovascular disease.

Differences in Vital Signs Between Elderly and Nonelderly Patients Prior to Ward Cardiac Arrest

Vital signs and composite scores, such as the Modified Early Warning Score, are used to identify high-risk ward patients and trigger rapid response teams. Although age-related vital sign changes are known to occur, little is known about the differences in vital signs between elderly and nonelderly patients prior to ward cardiac arrest. We aimed to compare the accuracy of vital signs for detecting cardiac arrest between elderly and nonelderly patients. Observational cohort study. Five hospitals in the United States. A total of 269,956 patient admissions to the wards with documented age, including 422 index ward cardiac arrests. None. Patient characteristics and vital signs prior to cardiac arrest were compared between elderly (age, 65 yr or older) and nonelderly (age, <65 yr) patients. The area under the receiver operating characteristic curve for vital signs and the Modified Early Warning Score were also compared. Elderly patients had a higher cardiac arrest rate (2.2 vs 1.0 per 1,000 ward admissions; p<0.001) and in-hospital mortality (2.9% vs 0.7%; p<0.001) than nonelderly patients. Within 4 hours of cardiac arrest, elderly patients had significantly lower mean heart rate (88 vs 99 beats/min; p<0.001), diastolic blood pressure (60 vs 66 mm Hg; p=0.007), shock index (0.82 vs 0.93; p<0.001), and Modified Early Warning Score (2.6 vs 3.3; p<0.001) and higher pulse pressure index (0.45 vs 0.41; p<0.001) and temperature (36.4°C vs 36.3°C; p=0.047). The area under the receiver operating characteristic curves for all vital signs and the Modified Early Warning Score were higher for nonelderly patients than elderly patients (Modified Early Warning Score area under the receiver operating characteristic curve 0.85 [95% CI, 0.82-0.88] vs 0.71 [95% CI, 0.68-0.75]; p<0.001). Vital signs more accurately detect cardiac arrest in nonelderly patients compared with elderly patients, which has important implications for how they are used for identifying critically ill patients. More accurate methods for risk stratification of elderly patients are necessary to decrease the occurrence of this devastating event.

A randomised comparative study of dexmedetomidine and midazolam for sedation during awake fiberoptic intubation in laproscopic cholecystectomy patients

Background: Fiberoptic nasotracheal intubation is an effective method for the management of patients with difficult airways. An ideal sedation regimen would ensure patient’s comfort, attenuation of airway reflexes, patient’s co-ordination, haemodynamic stability and amnesia. It is critical for both the surgeon and the anesthesiologist to understand the physiologic consequences of laparoscopy and to work in cooperation to achieve a good surgical outcome. Methods: Patients were randomly allocated to midazolam (MDZ) group (group 1) and dexmedetomidine (DEX) group (group 2). DEX patients received dexmedetomidine 1μg/kg, followed by an infusion of dexmedetomidine 0.1μg/kg/hr titrated to 0.7μg/kg/hr to achieve RSS ≥2. MDZ subjects received IV midazolam 0.05mg/kg with additional doses given to achieve a RSS ≥ 2. Measurements: Pulse rate, systolic and diastolic blood pressures and SpO 2 recorded during pre-oxygenation, one minute prior to introduction of fiberscope and then every minute for the following five minutes and beginning one minute before endotracheal intubation and then every minute until the endotracheal tube was secured, patient’s tolerance assessed on 5 point fiberoptic intubation score during fiberscopy and endotracheal intubation, total comfort score values assessed during pre-oxygenation, fiberscopy and endotracheal intubation and patient’s response to 24 hour post op questionnaire assessment were measured. Results: DEX group patients were significantly more quiet and more harmonius during awake fiberoptic intubation (AFOI) than were the MDZ group patients. The DEX group patients were found to have a lower mean Heart Rate than the MDZ patients. Conclusions: Both dexmedetomidine and midazolam are effective for fibreoptic intubation. Dexmedetomidine allows better endurance, stable haemodynamic status and a patent airway.

Physical and physiological profile of young female taekwondo athletes during simulated combat

Aim and Method. The purpose of this study was to describe the physical performance (acceleration, number of impacts, distance and maximum speed) and physiological response (heart rate and blood lactate) of young female taekwondo athletes during combat simulations. Material. The sample consisted of seven girls (13.1 ± 1.1 years), who participated in a simulated taekwondo competition. Results. The main results observed were: post match blood lactate = 4.19 ± 2.03 mmol. L-1; peak heart rate = 201 ± 7 bpm; maximum acceleration = 9.68 ± 0.52 G; number of impacts = 148 ± 42; total distance = 203 ± 69 m; and maximum speed = 7.07 [6.7, 8.2] km/h. A lower mean heart rate (P < 0.05; F = 8.333) was found in the first round (163 ± 14 bpm) compared with the second (182 ± 9 bpm) and third rounds (185 ± 10 bpm). Conclusions. The main findings of the present study are that young female taekwondo athletes presented with low blood lactate after the match, performed around 150 impacts during the match, which occurred each 1.37 m - given that the total displacement is around 200 m - with high acceleration, and the displacements were performed at moderate speeds. In addition the heart rate was lower in the first round compared to the other two rounds. © Idokan Poland Association.

Propofol versus dexmedetomidine as a sole sedative for diagnostic flexible bronchoscopy: a randomized double-blind study

Context Sedation is commonly used to improve patients' tolerance and comfort during flexible bronchoscopy (FB). Dexmedetomidine is a relatively novel sedative for use in FB. Aims The aim of this study was to compare dexmedetomidine and propofol as sole sedative agent in terms of hemodynamics, efficacy, safety and tolerance to the procedure among patients undergoing FB. Settings and design This study was carried out in a tertiary care teaching hospital, and was a double-blind randomized-controlled trial. Patients and methods Sixty patients were analyzed. Group 1 received propofol (1 mg/kg bolus, then 5 mg/kg/h infusion); group 2 received dexmedetomidine (1 mg/kg bolus, followed by 0.7 mg/kg/h infusion). Intraoperative (IOP) SpO 2 , heart rate, mean arterial pressure, and respiratory rate were recorded at nine time points. Primary outcome variables were hemodynamic variables, level of sedation, and recovery time (to reach an Aldrete score 10/10). Results The dexmedetomidine group showed significantly lower mean heart rate than the propofol group at IOP 0 , IOP 2 , and IOP 4 . The mean arterial pressure was significantly higher throughout the procedure in the dexmedetomidine group compared with the propofol group ( P 4 and IOP 6 ( P 2 was noted in the dexmedetomidine group (97.0 ± 1.1). Incidences of bucking and coughing were significantly higher in the dexmedetomidine group. Bronchoscopist visual analogue scale scores for coughing and satisfaction were significantly lower in the propofol group ( P P < 0.001). Conclusion Propofol showed superiority over dexmedetomidine in terms of safety, efficacy, adverse-effect profile, and tolerance to the procedure in patients undergoing diagnostic flexible bronchoscopy.

Effects of mother versus artificial rearing during the first 12 weeks of life on challenge responses of dairy cows

We investigated the effects of mother versus artificial rearing on the responses to a social and a non-social challenge in adulthood. Rearing of treatment groups only differed during the first 12 weeks of life. Artificially reared animals were separated from their mothers within 24h after birth and fed via an automatic milk feeder six times (A6, n=6) or twice (A2, n=5) a day. They were housed together with calves suckled by their mothers twice a day for 15min (M2, n=9) or with permanent access to the cow barn and thus to their mothers and the cow herd via selection gates (MP, n=6). After weaning animals of all rearing treatments were kept together until integration into the dairy cow herd. About 4.5 months after calving (age 31±1.4 months), cows were subjected to an isolation test and two novel objects tests (first: traffic cone, second: ball). ANOVA (behaviour; heart rate of novel object tests) and GLMM (heart rate and cortisol responses to isolation) were used for statistical analyses. During isolation, MP cows were more active: they walked significantly longer (P=0.036), tended to enter more squares in the middle area of the test arena (P=0.059), and to explore the arena or the outer environment for longer (P=0.056) than cows of the other three treatments. In addition, MP and A6 cows had the lowest mean heart rate during isolation, whereas after return into the herd the MP cows showed the lowest heart rate. Cortisol levels differed between groups dependent on sampling time (P=0.001), with MP cows having the lowest basal values but the highest after the isolation test. In the novel object tests, A6 cows tended to explore the traffic cone later (P=0.051), focused the ball earlier (P=0.040) and tended to use the area farther away from the ball more often than cows of the other three treatments (P=0.100). These results in 2.5-year-old cows suggest that rearing with permanent access to the mother and the herd increases sociality leading to higher behavioural activity during isolation and affects physiological stress reactions so that they resemble a reactive coping style, while reaction to novel objects in the home environment is not affected by mother rearing.

Abstract 332: Differences in Vital Signs Between Elderly and Non-Elderly Patients Prior to Ward Cardiac Arrest

BACKGROUND: Vital signs and composite risk scores, such as the Modified Early Warning Score (MEWS), are used to identify high-risk patients, trigger rapid response teams, and assist with triage decisions. Although age-related vital sign changes are known to occur, little is known about the differences in vital signs between elderly and non-elderly patients prior to ward cardiac arrest (CA). We compared the accuracy of vital signs and the MEWS for detecting CA between elderly and non-elderly patients. METHODS: All patients hospitalized on the wards from five hospitals were included in the study. Patient characteristics and vital signs prior to CA were compared between elderly (age ≥65 years) and non-elderly (age &lt;65 years) patients. The area under the receiver operating characteristic curve (AUC) was also calculated for vital signs and the MEWS for elderly and non-elderly ward patients for CA. RESULTS: A total of 269,956 admissions with documented age occurred during the study period, which included 422 index ward CAs. Within four hours of CA, elderly patients had significantly lower mean heart rate (88 vs. 99 beats per minute; P&lt;0.001), diastolic blood pressure (60 vs. 66 mm Hg; P=0.007), and shock index (0.82 vs. 0.93; P&lt;0.001), and higher pulse pressure index (0.45 vs. 0.41; P&lt;0.001) and temperature (97.6 vs. 97.3 °F; P=0.047). The AUCs for all vital signs and the MEWS were higher for non-elderly patients than elderly patients (MEWS AUC 0.85 (95% CI 0.82-0.88) vs. 0.71 (95% CI 0.68-0.75); P&lt;0.001). While the incidence of CA increased with age, accuracy of the MEWS decreased (Figure). CONCLUSIONS: Vital signs are much more accurate for detecting CA on the wards in non-elderly patients compared to elderly patients, which has important implications for how they are used for identifying critically ill patients. Further investigation into improving the accuracy of risk stratification for elderly patients is necessary in order to decrease their risk for this devastating event.