Tilt testing remains a valuable asset

Head-up tilt test (TT) has been used for >50 years to study heart rate/blood pressure adaptation to positional changes, to model responses to haemorrhage, to assess orthostatic hypotension, and to evaluate haemodynamic and neuroendocrine responses in congestive heart failure, autonomic dysfunction, and hypertension. During these studies, some subjects experienced syncope due to vasovagal reflex. As a result, tilt testing was incorporated into clinical assessment of syncope when the origin was unknown. Subsequently, clinical experience supports the diagnostic value of TT. This is highlighted in evidence-based professional practice guidelines, which provide advice for TT methodology and interpretation, while concurrently identifying its limitations. Thus, TT remains a valuable clinical asset, one that has added importantly to the appreciation of pathophysiology of syncope/collapse and, thereby, has improved care of syncopal patients.

Nicotine in various delivery systems of it and its effect on the heart-rate variability

n this experimental study heart rate variability (HRV) using electrocardiography was studied in a small group of volunteers (10 people) who have never smoked (4), ex-smokers (4) and active smokers (2). Different nicotine delivery systems and smoking simulators, including regular, nicotine-free and electronic cigarettes, tobacco heating systems, chewing gums and a completely new product on the domestic market – nicotine packs of oral fixation (NPOF) were used. Supplemented with hormonal studies (stress hormones in saliva and catecholamines in the blood), HRV analysis showed relatively small changes in HRV with systemic use of packs with moderate nicotine content (up to 6 mg), which makes this type of product a leader in biological safety among the studied alternative delivery systems nicotine.

Monitoring physiological responses and fluid balance of elite female beach handball players during an international tournament

Background and Study Aim. Despite its increasing popularity, beach handball has not been studied in terms of physiological responses. Thus the aim of this study was to demonstrate lactate and heart rate responses as well as urine specific gravity (USG) levels and fluid intakes of female university students who competed at an international beach handball tournament. Material and Methods. Five university students who are also handball players (age: 21±1,2, body weight: 56,6±6,4, height:1,61±0,06 and BMI: 21,7±1,43) voluntarily participated in this study. Heart rate (HR), lactate level (LA) and USG were measured before each and immediately after each competition and fluid intake during competition was monitored. Results: The mean values of lactate accumulation and heart rate before and after the match were 1,4 mmol and 87,3, 5,0 and 123,9, respectively. Athletes were euhydrated before the matches (USGmean=1,018) and only presented dehydration after the second match. Conclusions. Beach handball does not result in strenuous physiological effects according to heart rate and lactate responses. Their fluid intake was not enough to eliminate dehydration. Despite fluid availability during the match they presented dehydration at the second match.

Effects of Aircraft Noise Exposure on Heart Rate during Sleep in the Population Living Near Airports

Background Noise in the vicinity of airports is a public health problem. Many laboratory studies have shown that heart rate is altered during sleep after exposure to road or railway noise. Fewer studies have looked at the effects of exposure to aircraft noise on heart rate during sleep in populations living near airports. Objective The aim of this study was to investigate the relationship between the sound pressure level (SPL) of aircraft noise and heart rate during sleep in populations living near airports in France. Methods In total, 92 people living near the Paris-Charles de Gaulle and Toulouse-Blagnac airports participated in this study. Heart rate was recorded every 15 s during one night, using an Actiheart monitor, with simultaneous measurements of SPL of aircraft noise inside the participants’ bedrooms. Energy and event-related indicators were then estimated. Mixed linear regression models were applied, taking into account potential confounding factors, to investigate the relationship between energy indicators and heart rate during sleep measured every 15 s. Event-related analyses were also carried out in order to study the effects of an acoustic event associated with aircraft noise on heart rate during sleep. Results The more the SPL from all sources (LAeq,15s) and the SPL exceeded for 90% of the measurement period (LA90,15s) increased, the more heart rate also increased. No significant associations were observed between the maximum 1-s equivalent SPL associated with aircraft overflight (LAmax,1s) and differences between the heart rate recorded during or 15 or 30 s after an aircraft noise event and that recorded before the event. On the other hand, a positive and significant association was found between LAmax,1s and the heart rate amplitude calculated during an aircraft noise event. Results were unchanged when analyses were limited to participants who had lived more than five years in their present dwelling. Conclusion Our study shows that exposure to the maximum SPL linked to aircraft overflight affect the heart rate during sleep of residents near airports. However, further studies on a larger number of participants over several nights are needed to confirm these results.

Efeito agudo da ventilação não invasiva associada ao exercício físico sobre parâmetros cardiovasculares e respiratórios: um estudo de caso

Introdução: O método de suprimento de ventilação não invasivo (VNI) durante a realização de exercícios físicos tem sido utilizado como uma ferramenta auxiliar no tratamento de pacientes com doenças pulmonares. A literatura mostra que ainda há escassez de dados acerca dos efeitos da utilização da VNI durante a realização do exercício físico sobre os parâmetros cardiorrespiratórios.Objetivo: Avaliar o efeito do exercício físico associado a VNI sobre parâmetros cardiovasculares e respiratórios.Métodos: Participou deste estudo de caso um indivíduo do sexo masculino, saudável, com 27 anos de idade. Foram mensurados: frequência cardíaca (FC), variabilidade cardíaca (VFC), saturação periférica de oxigênio (SPO2), pressão arterial sistólica (PAS) e diastólica (PAD) e duplo produto (DP). Foram realizados dois treinos cardiorrespiratórios em esteira ergométrica, um sem VNI e o outro com VNI. As sessões de treinamento contemplaram duração de 40 min divididos em 5 min de aquecimento com intensidade entre 50% e 55% da FC reserva, 30 min de fase específica com intensidade entre 60% e 85% da FC reserva, e 5 min de desaquecimento com intensidade de 50% a 55% da FC reserva. Para avaliar as alterações das variáveis desfecho, foi estimada a variação percentual pelo coeficiente de variação.Resultados: A realização do exercício com VNI provocou alterações nos parâmetros cardiovasculares e respiratórios analisados, com destaque para redução da VFC (Δ%= -64,14) e PAD (Δ%= -45,82) em comparação à realização sem VNI.Conclusão: Os resultados do presente estudo sugerem que a realização do exercício físico com VNI pode beneficiar as respostas dos parâmetros cardiovasculares e respiratórios. Os resultados foram discutidos.Acute Effect of Non-Invasive Ventilation Associated with Physical Exercise on Cardiovascular and Respiratory Parameters: a Case StudyIntroduction: The noninvasive ventilation (NIV) method during physical exercise has been used as an auxiliary tool in the treatment of patients with pulmonary diseases. However, there is a lacune on the knowledge about cardiorespiratory parameters effects of NIV during physical exercise.Objective: To evaluate the effect of physical exercise associated with NIV on cardiovascular and respiratory parameters.Methods: A healthy, 27-year-old male was enrolled in this case study. Heart rate (HR), cardiac variability (HRV), peripheral oxygen saturation (SPO2), systolic blood pressure (SBP) and diastolic blood pressure (DBP) and double product (SD) were measured. Two cardiorespiratory treadmills were performed on treadmill, one without NIV and the other with NIV. The training sessions included 40 min duration divided in 5 min of heating with intensity between 50% and 55% of reserve HR, 30 min of specific phase with intensity between 60% and 85% of reserve HR, and 5 min of cooling with intensity of 50% to 55% of reserve FC. To express the changes of the variables, the percentage change was estimated by the coefficient of variation.Results: The exercise with NIV caused changes in cardiovascular and respiratory parameters, with a reduction in HRV (Δ% = -64.14) and DBP (Δ% = -45.82) in comparison with non-NIV.Conclusion: Our findings suggested that physical exercise with NIV use may benefit in association with exercise in relation to cardiovascular and respiratory parameters. The results were discussed.

Heart rate variability: a biomarker of dairy calf welfare

Dairy calf welfare is recognised to be compromised from common management practices. In this study heart rate variability (HRV) was used to measure stress in 25 young dairy calves to quantify the degraded welfare they experienced from weaning separation and isolation and also the painful disbudding procedure. It was shown the time spent on the cow before separation had a significant negative correlation to HRV (r2 = –0.68, P = 0.03). The longer a calf spent in isolation the lower its HRV 3 days after joining a group pen (P = 0.037). The removal of a dummy teat elicited a significant drop in HRV (P = 0.05), identifying the addictive properties of sucking in calves. Post disbudding stress, reflected by declining HRV values, was only partly alleviated by the non-steroidal anti-inflammatory drug meloxicam after 48 h. The findings showed calf welfare would be improved by reducing the time between birth and separation and also the days spent in single pens. Providing dummy teats for individually housed calves showed potential as a positive environmental enrichment. Meloxicam may improve welfare by alleviating some chronic pain following hot iron disbudding. We conclude these findings illustrate that HRV, as a science-based animal-centric biomarker of animal welfare, may be used to help improve farmed animal practice.

Ballistocardiographic Responses to Dynamic Facial Displays of Emotion While Sitting on the EMFi Chair

The aim of the present paper was to study heart rate changes during a video stimulation depicting two actors (male and female) producing dynamic facial expressions of happiness, sadness, and a neutral expression. We measured ballistocardiographic emotion-related heart rate responses with an unobtrusive measurement device called the EMFi chair. Ratings of subjective responses to the video stimuli were also collected. The results showed that the video stimuli evoked significantly different ratings of emotional valence and arousal. Heart rate decelerated in response to all stimuli and the deceleration was the strongest during negative stimulation. Furthermore, stimuli from the male actor evoked significantly larger arousal ratings and heart rate responses than the stimuli from the female actor. The results also showed differential responding between female and male participants. The present results support the hypothesis that heart rate decelerates in response to films depicting dynamic negative facial expressions. The present results also support the idea that the EMFi chair can be used to perceive emotional responses from people while they are interacting with technology.

QTC Dispersion and P-Wave Dispersion during Migraine Attacks

The aim of this study was to investigate increase of QTc dispersion and P-wave dispersion during migraine attacks. Fifty-five patients (16–65 years of age, 49 women, six men) with migraine were included in our study. Heart rate, QTc interval, maximum and minimum QTc interval, QTc dispersion, maximum and minimum P-wave duration and P-wave dispersion were measured from 12-lead ECG recording during migraine attacks and pain-free periods. ECGs were transferred to a personal computer via a scanner and then used for magnification of x400 by Adobe Photoshop software. Maximum QTc interval (454 ± 24 ms vs. 429 ± 23 ms, P < 0.001), QTc interval (443 ± 26 ms vs. 408 ± 22 ms, P <0.001) and QTc dispersion (63 ± 18 ms vs. 43 ± 14 ms, P <0.001) were found significantly higher during migraine attacks compared with pain-free periods. Maximum P-wave duration (107 ± 11 ms vs. 100 ± 11 ms, P <0.001) and P-wave dispersion (45 ± 13 ms vs. 35 ± 13 ms, P <0.001) were found higher during migraine attacks than pain-free periods. We concluded that migraine attacks are associated with increased QTc and P-wave dispersion compared with pain-free periods.

Beat-to-beat cardiovascular responses to rapid, low-level LBNP in humans

The hypothesis tested was that there are significant transient changes in the cardiovascular variables after rapid onset and release of mild lower body negative pressure (LBNP, −20 mmHg), even in experimental situations where there is no detectable change in steady-state values. Twelve subjects participated in the study. Heart rate, stroke volume (SV), cardiac output, mean arterial pressure (MAP), total peripheral resistance (TPR), acral and nonacral skin blood flow, and blood flow velocity in the brachial artery were continuously recorded during the pre-LBNP period (0–120 s), during LBNP (120–420 s), and during the post-LBNP period (420–600 s). The main finding was that MAP is transiently but strongly affected by rapid changes in LBNP as small as −20 mmHg. There was also a characteristic asymmetry in cardiovascular responses to the onset and release of LBNP, particularly in the responses in SV. The transient changes in MAP indicate that the neural responses that affect TPR are not fast enough to compensate for the rapid changes in LBNP. In this case, the arterial baroreceptors will be activated as well as the low-pressure baroreceptors that sense central venous pressure. This must be taken into consideration in future discussions of the results of LBNP protocols.