Heart Rate Trends Research Articles

Tachycardic and non-tachycardic responses in trauma patients with haemorrhagic injuries

BackgroundAnalyses of large databases have demonstrated that the association between heart rate (HR) and blood loss is weaker than what is taught by Advanced Trauma Life Support training. However, those studies had limited ability to generate a more descriptive paradigm, because they only examined a single HR value per patient. MethodsIn a comparative, retrospective analysis, we studied the temporal characteristics of HR through time in adult trauma patients with haemorrhage, based on documented injuries and transfusion of ≥3 units of red blood cells (RBCs). We analysed archived vital-sign data of up to 60 min during either pre-hospital or emergency department care. ResultsWe identified 133 trauma patients who met the inclusion criteria for major haemorrhage and 1640 control patients without haemorrhage. There were 55 haemorrhage patients with a normal median HR and 78 with tachycardia. Median ΔHR was −0.8 and +0.7 bpm per 10 min, respectively. Median time to documented hypotension was 8 and 5 min, respectively. RBCs were not significantly different; median volumes were 6 (IQR: 4–13) and 10 units (IQR: 5–16), respectively. Time-to-hypotension and mortality were not significantly different. Tachycardic patients were significantly younger (P < 0.05). Only 10 patients with normal HR developed transient/temporary tachycardia, and only 11 tachycardic patients developed a transient/temporary normal HR. ConclusionsThe current analysis suggests that some trauma patients with haemorrhage are continuously tachycardic while others have a normal HR. For both cohorts, hypotension typically develops within 30 min, without any consistent temporal increases or trends in HR.

Abstract P290: Maternal Aerobic Exercise Intervention Improves Fetal Heart and Growth Measures

Introduction: Self-reported maternal exercise is associated with improved heart and body size measures in the fetus. Currently, there is a gap in understanding how regular maternal aerobic exercise at recommended levels (150 min/wk) for pregnancy influence heart and body size in utero. Hypothesis: We assessed the hypothesis that offspring of women randomized to aerobic exercise will have lower heart rate (HR), higher ejection fractions (EF), and lighter fetal weight than offspring of women in the control group. Methods: Healthy pregnant women were randomly assigned to aerobic exercise or no intervention. Women performed aerobic activity at a moderate intensity for 150 min/wk from 16 weeks until delivery. Maternal demographics (age, pre-pregnancy BMI) as well as other activities were self-reported. Based on type and intensity, activities were converted to METs and then combined to yield METmin per week (METs X frequency per week X duration in minutes). A sonographer blinded to group assignment recorded fetal ultrasound. Data from 27 pregnancies (16 exercise, 11 control) were analyzed. To compare differences between groups (Active only=A; Quiet only=Q) independent t -tests were performed while regression analysis was conducted to determine predictors of fetal HR, our primary outcome. Results: Of the 16 exercisers, 6 were excluded (compliance 51-74%); the remaining 10 had &gt;80% compliance. There were no group differences in maternal demographics, i.e., age and pre-pregnancy BMI. All values were in the normal range for fetal heart and body size measures. While not statistically significant, there was trend for fetal HR to be lower in exercisers (p=0.14) while aortic (p=0.05) and pulmonary (p=0.22) diameter, right ventricular (RV) EF (p=0.17), and left ventricular (LV) EF (p=0.18) were slightly higher compared to controls. In the A state , the female HR of exercisers were lower (p=0.05), while male left ventricular (LV) EF (p=0.006), and all fetuses right ventricular (RV) EF (p=0.07) were increased relative to same gender controls. In the Q state , female aortic diameter (p=0.11) and all fetuses’ pulmonary diameter (p=0.04) were increased in exercisers relative to same gender controls. Exercise level during pregnancy was a significant predictor of fetal HR (R 2 =0.10; p=0.01). Fetal head to abdominal circumference ratio was appropriate in exercisers (1.0±0.1) relative to control (0.985±0.1) fetuses (p=0.09). The fetuses of exercisers were slightly lighter relative to fetuses of controls (p=0.20). Conclusion: These preliminary data support the positive influence of aerobic exercise at recommended levels on fetal health outcomes during pregnancy.

Dynamic psychophysiological correlates of a learning from text episode in relation to reading goals

This study aimed to investigate undergraduates' cardiac activity during an episode of complex learning from text. Specifically, we examined (a) heart rate (HR) and (b) heart rate variability (HRV) as psychophysiological measures while students read a science text and were tested on it. Reading goals were also taken into account: Students were asked to read for themselves to know more on a topic, or to read to perform well to gain course credit. Undergraduates (N = 50) were randomly assigned to one of the two reading goal conditions. Their HR and HRV were registered at baseline, while reading the text, during the testing phase, and while recovering from the task. Findings confirmed that in the condition with the reading goal focused on good performance, the students comprehended the text better than the students who read for themselves. Two mixed-effects models examined HR and HRV trends during the four phases of the learning episode. Findings showed a general trend in which students’ HRV was greater in the reading phase compared to baseline. HR decreased during reading and increased during the testing phase. This pattern indicates a deep cognitive effort of students while reading that gave way to higher psychophysiological arousal in the testing phase. Moreover, a series of linear regression models revealed that being under aroused and in a state of receptive calm during the reading phase allowed greater performance. Educational implications are drawn.

Total intravenous versus desflurane-based anesthesia for shunt procedure in pediatric congenital cyanotic heart disease

Background Congenital cyanotic heart disease (CCHD), inclusive of all types of cyanotic heart disease with resulting hypoxemia and hypoxia, has diverse multisystem effects, including erythrocytosis, hyperviscosity, cholelithiasis, cerebral abscess, vascular dysfunction, and hemoptysis. Most, but not all, patients with CCHD, undergo surgical repair in childhood, resulting in either an elimination or reduction in the degree of hypoxemia and its complications. Systemic-to-pulmonary artery shunt is a necessity as a life-saving procedure that is carried out through placement of extracardiac systemic-to-pulmonary artery shunts, using many procedures such as Blalock–Taussig shunt procedure or its modification [modified Blalock–Taussig shunt (MBTS)], which is commonly used nowadays, modified Blalock–Thomas–Taussig shunt (commonly called the MBTS) is a surgical procedure used to increase pulmonary blood flow for palliation in duct-dependent cyanotic heart defects such as pulmonary atresia, which are common causes of blue baby syndrome. In this procedure, there is temporarily direction of the blood flow to the lungs and relieve cyanosis. Traditionally, these surgical procedures are accomplished by either a total intravenous anesthesia (TIVA) or inhalational-based anesthesia. The TIVA technique achieves hemodynamic stability but has many disadvantages such as increases in the period of mechanical ventilation and its associated complications, and increase in ICU stay. Although inhalational anesthetic-based technique may be associated with myocardial depression and dysarrythmias (up to ventricular arrhythmia), but, due to lower blood solubility, facilitates early awakening and endotracheal extubation; this technique decreases the duration of mechanical ventilation, ICU stay, and, therefore, total hospital stay. Patients and methods Forty ASA classes III and IV patients between 18 months and 6 years, scheduled for MBTS procedure for repairing CCHD, were to undergo systemic to pulmonary shunt using cardiopulmonary bypass (CPB) after median sternotomy. They were divided into two groups: patients in the TIVA group (n=20) were administered a combination of midazolam–fentanyl–propofol along with neuromuscular blockade, whereas the desflurane group (n=20) was administered desflurane with 0.6–1 MAC in 100% oxygen with a combination of fentanyl with neuromuscular blockade. Hemodynamic parameters [heart rate (HR), mean blood pressure], duration of elective ventilation, incidence of supraventricular tachycardia and ventricular tachycardia/ventricular fibrillation, and level of myocardial injury were detected by cardiac troponin I as a cardiac biomarker for myocardial injury recorded as primary outcome, whereas duration of inotrope use, ICU and hospital stay, and serum creatinine levels were recorded preoperatively, thereafter, at 24 h postoperatively, they were recorded as secondary outcome. Any serious adverse events, such as acute renal injury, or any other major cardiovascular/neurologic events were recorded. Results Repeated measure analysis was carried out to see the trend in HR from HR1 (at baseline) in both groups, HRs HR2 (just prior to CPB), HR3 (weaning from CPB), and HR4 (arrival at ICU) were significantly higher than HR1 (P&lt;0.001). The mean arterial pressures recorded at time intervals where T2 (just prior to CPB) and T4 (arrival at ICU) were found to be significantly lower in patients included in the TIVA than in the desflurane group (P=0.003 and 0.002, respectively), but mean arterial pressure values at T1 (at baseline) and T3 (weaning from CPB) were insignificant in both the groups (P&gt;0.05). Duration of mechanical ventilation, ICU stay and hospital stay were lower in the desflurane group compared with the TIVA group (P&lt;0.005). While patients in the TIVA group recorded significantly lower inotrope use than those in the desflurane group (P&lt;0.001). Likewise, the creatinine values measured at baseline and 24 h postoperatively were compared in both groups and also, inbetween group itself, were only significantly increased in the TIVA group (P=0.018). For cardiac troponin I levels, at T2 there were significantly higher than those at T1 in the TIVA group (P=0.001) when compared to the desflurane group (P=0.836). Conclusion TIVA has the advantage of hemodynamic stability, but it prolongs the duration of controlled ventilation and length of hospital stay. The current study demonstrated that a desflurane-based anesthetic provides comparable stability, early recovery of myocardial contractility, decreased duration of controlled ventilation, duration of ICU admissions, and total hospital stay.

Efficacy of dexmedetomidine versus remifentanil to blunt the hemodynamic response to laryngoscopy and orotracheal intubation: a randomized clinical trial.

The study aims to compare the efficacy of dexmedetomidine (DEX) vs. remifentanil (REM) to blunt the hemodynamic response to laryngoscopy and orotracheal intubation. Enrolled in a double-blind clinical trial, 124 patients undergoing elective surgery under general anesthesia at Amirkabir Hospital (Arak, Iran), were assigned into four groups equally (31 patients in each group), DEX, REM, DEX-REM, and normal saline (NS), who received intravenous DEX (1 µg/kg), REM (1 µg/kg), their equal mixture (each 0.5 µg/kg, 1 minute before tracheal intubation), and NS, respectively. Then, blood pressure (BP), heart rate (HR), and arterial oxygen saturation (SaO2) were measured on arrival to the operating room, 1 minute before laryngoscopy and tracheal intubation, immediately after intubation, and afterwards every 5 to 15 minutes, and finally the data were analyzed using SPSS 18.0. The groups were same regarding to age, sex and baseline hemodynamic variables including mean of BP (P = 0.157), HR (P = 0.105) and SaO2 (P = 0.366). Tukey post-hoc test showed that there DEX, REM, and a DEX + REM groups was same regarding to MBP and HR, but these hemodynamic responses were higher in NS group than other groups at all time after laryngoscopy and intubation (P < 0.05). Moreover, repeated measure test showed a decreasing trend in MBP and HR in three intervention groups at all time after intubation (P > 0.05). A DEX/REM mixture had the lowest BP and three intervention groups had lower HR than the NS group. A mixture of the drugs used seems to lead to not only a prevented increase in HR and BP during laryngoscopy but also a decreased BP and HR. This study was registered in Iranian Registry Clinical Center with the registration No. IRCT2016092722254N1.

Abstract 21029: Achieving High Retention in Mobile Health Research Using Design Principles Adopted From Widely Popular Consumer Mobile Apps

Introduction: While mHealth platforms can enable rapid participant recruitment, the first 5 ResearchKit apps retained less than 10% of daily participants after the first 90 days, whereas well-optimized consumer mobile apps like Instagram and Twitter retain 31% and 48%, respectively. We proposed to apply design principles from the world of consumer internet to achieve high engagement and retention in a mHealth study. Methods: We enrolled 14,011 users of Cardiogram for Apple Watch app into the Health eHeart Study, an IRB-approved study at UCSF. We applied 3 key design principles to drive engagement and retention. First, give valuable insights back to user—e.g., notify users of abnormal heart rate spikes, and show when exercise caused a lower resting heart rate trend—using Gottman’s ratio: for every negative insight, give 5 positive ones. Second, minimize latency so users’ data updates many times per day. Third, use simple user interfaces that easily visualize trends and provide insights in small digestible formats. Results: Mean age was 42.3 ± 12.1, 31% were women. Seven days after app install, 64% of participants were active; 63% were active after 30 days, and 54% after 90 days. Retention was consistent across age groups—day 90 retention was 52% for 20-40 y.o., 55% for 40-60, and 49% for above 60. Refreshing data as frequently as possible had the highest impact on user engagement—in A/B testing, where heart rate visualizations were updated less frequently, we saw 20.9% drop in daily active users (51951 to 41094) within 7 days. The ratio of daily to monthly active users, a key measure of engagement, is 69.8% in our study, while average mHealth app is 8%. Conclusions: By applying design techniques from consumer mobile apps, we achieved day 90 retention 5x higher than the best ResearchKit app, showing that mHealth studies can retain large cohorts of participants and collect unique ambulatory health data with high engagement, improving the impact of mobile health interventions.

Wearable Sensors and Their Metrics for Measuring Comprehensive Occupational Fatigue: A Scoping Review

Extensive research has been conducted to study the effects of physical and sleep related fatigue on occupational health and safety. However, fatigue is a complex multidimensional construct, that is task- and occupation-dependent, and our knowledge on how to measure this complex construct is limited. A scoping review was conducted to: 1) review sensors and their metrics currently employed in occupational fatigue studies, 2) identify overlap between sensors and associated metrics that can be leveraged to assess comprehensive fatigue, 3) investigating the effectiveness of the sensors/metrics, and 4) recommended potential sensor/metric combinations to evaluate comprehensive fatigue. 512 unique abstracts were identified through Ovid-MEDLINE, MEDLINE, Embase and Cinal databases and application of the inclusion/exclusion criteria resulted in 27 articles that were included for the review. Heart rate sensors and actigraphs were identified to be the most suitable devices to study comprehensive fatigue. Heart rate trend within the heart rate sensor, and sleep length and sleep efficiency within actigraphs were found to be the most popular and reliable metrics for measuring occupational fatigue.

Effectiveness of Ice-Sheet Cooling Following Exertional Hyperthermia.

The procedure of wrapping a heat casualty in ice-water soaked bed sheets to reduce core temperature has received little investigation, despite the practice and recommendation for its use in some military settings. Thus, the purpose of this study was to investigate the cooling efficacy of ice-sheet cooling (ISC) following exertional hyperthermia. 13 (11 males, 2 females) participants (age = 23 ± 3 years, height = 176.5 ± 10.3 cm, mass = 78.6 ± 15.3 kg, body fat = 19.6 ± 8.6%, and body surface area = 1.95 ± 0.22 m2) volunteered to complete 2 randomized, crossover design trials on an outdoor recreation field (34.4 ± 1.4°C, 54.4 ± 4.1% relative humidity). Each trial consisted of exercise (self-paced 400-m warm-up, 1,609-m run, and 100-m sprints) followed by 15 minutes of either lying supine in the shade with no treatment (control [CON]) or being treated with ice-water soaked sheets wrapped around their body (ISC). Physiological (rectal temperature [Tre], heart rate, mean-weighted skin temperature) and perceptual measures (thermal sensation, rating of perceived exertion) were assessed after each exercise protocol, every 3 minutes during treatment, and every 5 minutes during recovery. By design, there were no differences during exercise between ISC and CON for Tre (p = 0.16), skin temperature (p = 0.52), heart rate (p = 0.62), thermal sensation (p = 0.89), or rating of perceived exertion (p = 0.99). There were greater decreases in Tre at 3 (ISC 0.33 ± 0.26°C vs. CON 0.03 ± 0.30°C, p = 0.01) and 6 minutes (ISC 0.47 ± 0.27°C vs. CON 0.30 ± 0.19°C, p = 0.05) of treatment; however, the overall rate of cooling was not different between trials (CON 0.05 ± 0.02°C/min vs. ISC 0.06 ± 0.02°C/min, p = 0.72). Skin temperature (Tsk) was significantly reduced from 3 minutes (ISC 34.4 ± 1.7°C vs. CON 36.6 ± 0.5°C, p = 0.007) through 15 minutes (ISC 32.4 ± 1.5 vs. CON 36.1 ± 0.4°C, p < 0.001) of treatment. There was a trend for lower heart rate with ISC (p = 0.051). Thermal sensation was reduced from 3 minutes of treatment (ISC 3.5 ± 0.9 vs. CON 4.5 ± 0.6, p = 0.002) through 15 minutes (ISC 2.8 ± 1.0 vs. CON 3.9 ± 0.4, p = 0.005). ISC does not provide effective reduction in Tre following exertional hyperthermia compared to no treatment. However, perceptual benefits may warrant the use of ISC in settings where rapid reductions in core temperature are not a concern (i.e., recovery from exercise). Thus, clinicians should continue to utilize validated techniques (i.e., cold-water immersion) for the treatment of exertional heat illnesses.

Short-term association between personal exposure to noise and heart rate variability: The RECORD MultiSensor Study

BackgroundStudies revealed long-term associations between noise exposure and cardiovascular health, but the underlying short-term mechanisms remain uncertain. ObjectivesTo explore the concomitant and lagged short-term associations between personal exposure to noise and heart rate variability (HRV) in a real life setting in the Île-de-France region. MethodsThe RECORD MultiSensor Study collected between July 2014 and June 2015 noise and heart rate data for 75 participants, aged 34–74 years, in their living environments for 7 days using a personal dosimeter and electrocardiography (ECG) sensor on the chest. HRV parameters and noise levels were calculated for 5-min windows. Short-term relationships between noise level and log-transformed HRV parameters were assessed using mixed effects models with a random intercept for participants and a temporal autocorrelation structure, adjusted for heart rate, physical activity (accelerometry), and short-term trends. ResultsAn increase by one dB(A) of A-weighted equivalent sound pressure level (Leq) was associated with a 0.97% concomitant increase of the Standard deviation of normal to normal intervals (SDNN) (95% CI: 0.92, 1.02), of 2.08% of the Low frequency band power (LF) (95% CI: 1.97, 2.18), of 1.30% of the High frequency band power (HF) (95% CI: 1.17, 1.43), and of 1.16% of the LF/HF ratio (95% CI: 1.10, 1.23). The analysis of lagged exposures to noise adjusted for the concomitant exposure illustrates the dynamic of recovery of the autonomic nervous system. Non-linear associations were documented with all HRV parameters with the exception of HF. Piecewise regression revealed that the association was almost 6 times stronger below than above 65 Leq dB(A) for the SDNN and LF/HF ratio. ConclusionPersonal noise exposure was found to be related to a concomitant increase of the overall HRV, with evidence of imbalance of the autonomic nervous system towards sympathetic activity, a pathway to increased cardiovascular morbidity and mortality.

Evaluation of Heart Rate in Daily Life Based on 10 Million Samples Database

This research uses a very-large amount of heart rate data (approximately 10 millions entries) collected on one million persons to investigate heart rate trends in daily life. Trends were examined regarding both human characteristics (gender, age, BMI), and environmental properties (hour of the day, day of the week, season). Concerning the relation between heart rate and gender, women’s heart rate trend was significantly lower compared to men’s. As for the relation between heart rate and age, on one hand, women’s heart rate tends to become lower with aging. On the other hand, men’s heart rate tends to keep increasing until the 50’s. Also, men’s heart rate is lower than women’s in the 10’s and 20’s, the trend becomes opposite from the 30’s. In the relation between heart rate and BMI (Body Mass Index), heart rate is significantly higher for users with higher BMI. Regarding diurnal fluctuation of heart rate, it has been confirmed to take its lowest between 3 A.M. and 6 A.M., then increasing regularly until the peak between noon and 3 P.M., after which it decreases during the evening through the night. As for in-week fluctuation, the trend of higher heart rate during the week and lower heart rate during week-ends and holidays has been comfirmed. Specialy, heart rate remarkably increases from Sunday to Monday. Finally, concerning seasonal fluctuation trend, heart rate is decreasing from summer to autumn, and is at his highest level in winter. The results of this research tend to correspond with previous studies that have been carried out on smaller samples and fewer subjects, demonstrating the credibilitay and validity of the data measured by our system. Moreover, on a public health point of view, we can say that it is important to take into account various human properties and spatio-temporal characteristics when having a comparative analysis of people’s health distribution. We think the knowledge obtained in this research can be applied practically to the whole society as an indication for health care and various diseases prevention.

Blood Pressure and Heart Rate Measures Associated With Increased Risk of Covert Brain Infarction and Worsening Leukoaraiosis in Older Adults.

In people without previous stroke, covert findings on serial magnetic resonance imaging (MRI) of incident brain infarcts and worsening leukoaraiosis are associated with increased risk for ischemic stroke and dementia. We evaluated whether various measures of blood pressure (BP) and heart rate are associated with these MRI findings. In the CHS (Cardiovascular Health Study), a longitudinal cohort study of older adults, we used relative risk regression to assess the associations of mean, variability, and trend in systolic BP, diastolic BP, and heart rate measured at 4 annual clinic visits between 2 brain MRIs with incident covert brain infarction and worsening white matter grade (using a 10-point scale to characterize leukoaraiosis). We included participants who had both brain MRIs, no stroke before the follow-up MRI, and no change in antihypertensive medication status during follow-up. Among 878 eligible participants, incident covert brain infarction occurred in 15% and worsening white matter grade in 27%. Mean systolic BP was associated with increased risk for incident covert brain infarction (relative risk per 10 mm Hg, 1.28; 95% confidence interval, 1.12-1.47), and mean diastolic BP was associated with increased risk for worsening white matter grade (relative risk per 10 mm Hg, 1.45; 95% confidence interval, 1.24-1.69). These findings persisted in secondary and sensitivity analyses. Elevated mean systolic BP is associated with increased risk for covert brain infarction, and elevated mean diastolic BP is associated with increased risk for worsening leukoaraiosis. These findings reinforce the importance of hypertension in the development of silent cerebrovascular diseases, but the pathophysiologic relationships to BP for each may differ.

Clinical application of cardiopulmonary resuscitation with abdominal lifting and compression in emergency treatment

To investigate the clinical value of cardiopulmonary resuscitation (CPR) with abdominal lifting and compression on patients with breathing and cardiac arrest induced by severe chest trauma. Sixty-six breathing and cardiac arrest patients induced by severe chest trauma admitted to the General Hospital of Jingyuan Coal Industry Group Company from October 2011 to October 2016 were enrolled, and they were divided into abdominal lifting and compression group (n = 32) and unarmed abdominal compression group (n = 34) by random number table. The patients in both two groups were given the airway open, respiration support, defibrillation treatment, venous access establishment, vasoactive drugs application and other conventional treatments. On the basis of the routine treatment, the patients in abdominal lifting and compression group were given application of abdominal lifting and compression device with 100 times/min frequency and continuously alternating press down to lift the abdomen, the amplitude of pressing and pulling were 3-5 cm below or above the original level of the abdomen. Those in unarmed abdominal compression group were given abdominal CPR pressing method by hand, the frequency of pressing and depth of subsidence was the same as abdominal lifting and compression group. Heart rate (HR) and arterial blood gas at 30 minutes after CPR as well as the success rate of resuscitation were compared between the two groups. The changes in HR, mean arterial pressure (MAP) and pulse oxygen saturation (SpO2) before and 30 minutes and 60 minutes after CPR were dynamically observed in patients with restoration of spontaneous circulation (ROSC) after abdominal lifting and compression CPR treatment. Compared with the unarmed abdominal compression group, HR (bmp: 136.13±6.14 vs. 148.45±5.16) and arterial partial pressure of carbon dioxide [PaCO2 (mmHg, 1 mmHg = 0.133 kPa): 48.51±2.60 vs. 62.51±2.50] at 30 minutes after CPR in abdominal lifting and compression group were significantly lowered, and arterial partial pressure of oxygen (PaO2) was significantly increased (mmHg: 88.07±3.92 vs. 74.12±2.12, all P < 0.05). Four patients with ROSC were found in abdominal lifting and compression group, and 2 in unarmed abdominal compression group. The success rate of resuscitation in abdominal lifting and compression group was significantly higher than that of unarmed abdominal compression group (12.50% vs. 5.82%, P < 0.05). In 4 patients with ROSC after abdominal lifting and compression CPR showed a downward trend in HR and an upward trend in MAP and SpO2 with CPR time prolongation. The effect of abdominal lifting and compression CPR is better than that of unarmed abdominal compression CPR, which is of great value for the life saving of patients with breathing and cardiac arrest induced by severe chest trauma.

Major depressive disorder and generalized anxiety disorder show different autonomic dysregulations revealed by heart-rate variability analysis in first-onset drug-naïve patients without comorbidity.

The aim of the present study was to examine whether depression and anxiety disorder manifest different autonomic dysregulations using heart-rate variability (HRV) and heart rate (HR) measurements. HRV and HR were recorded both at rest and during task execution (random-number generation) in first-onset drug-naïve patients with major depressive disorder (MDD, n = 14) and generalized anxiety disorder (GAD, n = 11) as well as in healthy controls (n = 41). The patients showed no comorbidity of depression and anxiety disorder. GAD patients did not exhibit panic or phobic symptoms at the time of measurement. Following power spectrum analysis of HR trend, the high- (HF) and low-frequency (LF) components, the sum (LF + HF), and the LF/HF ratio were compared among the groups. In the MDD patients, as previously reported, HF was low and the LF/HF ratio was high during the initial-rest condition, and HF was less reactive to the task. In contrast, GAD patients showed significantly high HF, although autonomic reactivity was not impaired. The results indicate that baseline autonomic activity and its reactivity to behavioral changes are different between MDD and GAD in the early stage of illness. High parasympathetic tone in GAD may reflect responses of the parasympathetic system to anxiety. MDD is accompanied by an autonomic shift toward sympathetic activation and a reduced reactivity to task.

Variations on a Precision Medicine Theme: One Size Fits Some.

Precision medicine, or personalized medicine, refers to the tailoring of therapy to the individual characteristics of patients. It can be applicable to patients with advanced disease and to preventative interventions as well. The impetus for this approach came from sequencing of the human genome and the anticipation that an individual’s sequence would inform treatment, aided perhaps by Big Data algorithms. In heart failure, advances in omics have occurred alongside other disciplines but from a practical standpoint, our ability to provide precision medicine remains more or less in the neutral position. In this article, we maintain that despite significant limitations on our ability to use genotyping or Big Data to impact real-world heart failure care in real time, we are in fact practicing a significant degree of precision medicine and can continue to do more of the same with relatively modest changes in approach to practice. The advent of angiotensin-converting enzyme inhibitors and β-blockers impacted heart failure therapeutics1,2 in a truly revolutionary way. They are recommended across all New York Heart Association classes for the management of patients with heart failure with reduced ejection fraction (EF).3 Although β-blockers have not been critically examined in patients with class I symptoms, we accept the notion that for these 2 classes of drugs, one size truly does fit all. We argue about dose, not whether we should use the drugs.4,5 We can also debate the duration of treatment in patients who have normalized their EF and the likelihood of recurrence of heart failure if those medications are stopped. Fundamentally, the importance of blockade of the renin–angiotensin system and adrenergic stimulation are fully accepted concepts that apply in young and old, symptomatic and asymptomatic, borderline low and very low EF, left ventricular failure and biventricular failure, in the …

Age‐Related Variations in Ventricular Response Rate in Individuals with Persistent or Permanent Atrial Fibrillation

To the Editor: Atrial fibrillation (AF) is the most frequent sustained arrhythmia.1 Its prevalence increases with age, affecting almost 20% of individuals aged 85 and older2 and resulting in substantial health care use and morbidity.3 Rapid heart rate (HR) is the most obvious cause of symptoms, which in turn are associated with lower quality of life and higher risk of hospitalization.4 The influence of age on ventricular rate has been previously investigated in individuals with paroxysmal AF5 but has not been well characterized in those with persistent or permanent AF. Thus, the goal was to evaluate the effect of age on ventricular response rate in these individuals. Thirty-two thousand seven hundred seventeen 24-hour electrocardiographic Holter recordings were performed in the Complexo Hospitalario Universitario A Coruña, Instituto de Investigación Biomédica de A Coruña, A Coruña, Spain, between March 1, 2000, and November 14, 2015. Those in which AF was verified were initially considered for inclusion in this study. When several Holter monitoring studies were available for the same individual, the first was selected, resulting in 3,109 available recordings with AF. Individuals in whom AF was not the sole cardiac rhythm identified throughout the recordings or in whom a pacemaker had been previously implanted were also excluded (n = 701), leaving a final study population of 2,408 individuals. Maximal, minimal, and mean HR over the 24-hour period were collected for each Holter recording. HR range was estimated as the difference between maximal and minimal HR. Correlations between age and HR were assessed using Spearman rank correlation coefficients. Age was categorized into four groups (<50, 50–64, 65–79, ≥80), and trends in HR were assessed according to age group. The relationship between age and the need for pacemaker implantation within 1 year was also evaluated in the subset of 2,178 participants with AF who underwent Holter monitoring between March 1, 2000, and November 14, 2014. The statistical significance of trends across age intervals was assessed using the Cochran-Armitage test for categorical variables and the Cuzick nonparametric test for continuous variables. The ethics committee of A Coruña-Ferrol approved this study. Mean age was 75 ± 10, and 1,381 subjects (57.4%) were male. Maximal HR was 134 ± 32 beats per minute (bpm), minimal HR was 41 ± 11 bpm, and mean HR was 74 ± 17 bpm. There were significant inverse correlations between age and maximal HR (ρ = −0.306, P < .001), minimal HR (ρ = −0.149, P < .001), mean HR (ρ = −0.230, P < .001), and HR range (ρ = −0.303, P < .001). Table 1 shows the trends in maximal, minimal, and mean HR and HR range according to age group; all these parameters decreased gradually and significantly with age. The likelihood of pacemaker implantation within 1 year after Holter recordings also increased progressively with age, (<50, 4.7%; 50–64, 5.4%; 65–79, 8.7%; ≥80, 10.2%; P for trend <.001). An inverse association was found between age and ventricular rate in individuals with persistent or permanent AF. The need for pacemaker implantation in these individuals also increased progressively with age. Although age has been shown to influence HR during episodes of paroxysmal AF,5 this study complements and expands this observation to individuals with persistent or permanent AF. The slower ventricular rate with increasing age in these subjects may mainly be due to progressive atrioventricular conduction delay6 and atrial structural changes. Impaired atrioventricular conduction or age-related decreases in sinus node function may also explain the gradual increase in the probability of pacemaker implantation during follow-up in individuals with AF.7 A lower level of physical activity in older adults might further account for the greater reduction in maximal and mean HR with age than in minimal HR. The decrease in minimal HR with increasing age occurred despite well-known higher vagal tone at rest in younger individuals. One might infer that the dosage of negative chronotropic drugs required for adequate HR control in elderly adults might be lower and that these medications may be associated with greater probability of symptomatic bradycardia than in their younger counterparts. Nonetheless, no attempt was made to account for the effect of such medications, and the study was not designed to test these assertions. Furthermore, the indications for pacemaker implantation were not evaluated. In conclusion, HR tended to decrease with age in individuals with persistent or permanent AF, and there was an apparently congruent, gradual increase in the need for pacemaker implantation with aging in these individuals. Conflict of Interest: The authors declare no competing interests. Author Contributions: Bouzas-Mosquera: study concept and design, acquisition of subjects and data, analysis and interpretation of data, preparation of manuscript. Broullón, Martínez, Yáñez, Álvarez-García, Peteiro, Vázquez-Rodríguez: acquisition of subjects and data, review of manuscript. Sponsor's Role: The study had no external funding.

A laser Doppler system for monitoring cerebral microcirculation: implementation and evaluation during neurosurgery.

The aim of this study was to adapt and evaluate laser Doppler perfusion monitoring (LDPM) together with custom-designed brain probes and software for continuous recording of cerebral microcirculation in patients undergoing neurosurgery. The LDPM system was used to record perfusion and backscattered light (TLI). These parameters were displayed together with the extracted heart rate (HR), pulsatility index (PI) and signal trends from adjustable time intervals. Technical evaluation was done on skin during thermal provocation. Clinical measurements were performed on ten patients undergoing brain tumour surgery. Data from 76 tissue sites were captured with a length varying between 10 s to 15 min. Statistical comparisons were done using Mann-Whitney tests. Grey and tumour tissue could be separated from white matter using the TLI signal (p < 0.05). The perfusion was significantly higher in grey and tumour tissue compared to white matter (p < 0.005). LDPM was successfully used as an intraoperative tool for monitoring local blood flow and additional parameters linked to cerebral microcirculation (perfusion, TLI, HR and PI) during tumour resection. The systems stability opens up for studies in the postoperative care of patients with, for example, traumatic brain injury or subarachnoid haemorrhage.

Impact of Heart Rate Dynamics on Mortality in the Early Phase after Ischemic Stroke: A Prospective Observational Trial

Growing evidence suggests that the heart rate (HR) at rest is an independent predictor of cardiovascular mortality. In ischemic stroke, continuous monitoring of HR is the standard of care, but systematic data on its dynamics and prognostic value during the acute phase are limited. In this prospective observational study, HR was measured by continuous electrocardiographic monitoring on admission and during the first 72 hours of care among patients who were awake with ischemic stroke and survived until discharge. Functional outcome was assessed after 90 days. Data from 702 consecutive patients were analyzed (median age, 73 years, 54% men). The time course of HR was initially characterized by a rapid decline during the first 12 hours after admission. Among patients who survived until day 90, this was followed by a continuous downward trend in HR, whereas death after discharge was associated with a secondary increase and a reversal point 12 hours after admission. After adjustment for established risk factors, this secondary increase during the acute period was an independent predictor of death (hazard ratio, 3.73; 95% confidence interval, 1.47-9.43; P = .005). A secondary rise of HR during care for acute ischemic stroke is an early sign of fatality and may represent a surrogate for an unfavorable sympathetic disinhibition. Further research is warranted to clarify the role of targeted HR reduction after ischemic stroke (http://clinicaltrials.gov/, unique identifier NCT01858779).

Impact of nocturnal heart rate variability on cerebral small-vessel disease progression: a longitudinal study in community-dwelling elderly Japanese.

Recent evidence has shown an effect of ambulatory heart rate (HR) on cardiovascular events and mortality. Our objective was to determine whether ambulatory HR was related to the progression of cerebral small-vessel disease (SVD) or cognitive decline in community-dwelling elderly people. A cohort of 190 community-dwelling elderly people underwent an ambulatory blood pressure monitoring (ABPM), brain magnetic resonance imaging (MRI) and cognitive testing at baseline, with MRI and cognitive tests repeated 4 years later. HR variability in ABPM was quantified by the s.d. (s.d. and the root mean square of successive differences (RMSSD), and the relationship between HR variability and the progression of SVD/cognitive decline was investigated. We also assessed the association of nighttime HR variability and nocturnal HR dipping. The nighttime RMSSD of participants with the progression of SVD was significantly higher than that of those without progression of SVD (P<0.05). Moreover, nighttime RMSSD was independently associated with the progression of SVD (1 b.p.m. increment: odds ratio=1.13, 95% confidence interval=1.04-1.24, P<0.01). We failed to confirm an association between cognitive decline and nighttime HR variability. However, s.d. in the daytime and 24-h HR were independently related to cognitive decline (P<0.05). Nocturnal HR dipping was least in the top quartiles of nighttime HR variability, with a monotonic trend of nocturnal HR dipping that was dependent on the quartiles of nighttime HR variability indices (P<0.01). Increased HR variability during the night is a predictor of the progression of SVD in community-dwelling elderly people.

Accuracy of continuous noninvasive hemoglobin monitoring for the prediction of blood transfusions in trauma patients.

Early detection of hemorrhagic shock is required to facilitate prompt coordination of blood component therapy delivery to the bedside and to expedite performance of lifesaving interventions. Standard physical findings and vital signs are difficult to measure during the acute resuscitation stage, and these measures are often inaccurate until patients deteriorate to a state of decompensated shock. The aim of this study is to examine a severely injured trauma patient population to determine whether a noninvasive SpHb monitor can predict the need for urgent blood transfusion (universal donor or additional urgent blood transfusion) during the first 12 h of trauma patient resuscitation. We hypothesize that trends in continuous SpHb, combined with easily derived patient-specific factors, can identify the immediate need for transfusion in trauma patients. Subjects were enrolled if directly admitted to the trauma center, >17 years of age, and with a shock index (heart rate/systolic blood pressure) >0.62. Upon admission, a Masimo Radical-7 co-oximeter sensor (Masimo Corporation, Irvine, CA) was applied, providing measurement of continuous non-invasive hemoglobin (SpHb) levels. Blood was drawn and hemoglobin concentration analyzed and conventional pulse oximetry photopletysmograph signals were continuously recorded. Demographic information and both prehospital and admission vital signs were collected. The primary outcome was transfusion of at least one unit of packed red blood cells within 24 h of admission. Eight regression models (C1-C8) were evaluated for the prediction of blood use by comparing area under receiver operating curve (AUROC) at different time intervals after admission. 711 subjects had continuous vital signs waveforms available, to include heart rate (HR), SpHb and SpO2 trends. When SpHb was monitored for 15 min, SpHb did not increase AUROC for prediction of transfusion. The highest ROC was recorded for model C8 (age, sex, prehospital shock index, admission HR, SpHb and SpO2) for the prediction of blood products within the first 3 h of admission. When data from 15 min of continuous monitoring were analyzed, significant improvement in AUROC occurred as more variables were added to the model; however, the addition of SpHb to any of the models did not improve AUROC significantly for prediction of blood use within the first 3 h of admission in comparison to analysis of conventional oximetry features. The results demonstrate that SpHb monitoring, accompanied by continuous vital signs data and adjusted for age and sex, has good accuracy for the prediction of need for transfusion; however, as an independent variable, SpHb did not enhance predictive models in comparison to use of features extracted from conventional pulse oximetry. Nor was shock index better than conventional oximetry at discriminating hemorrhaging and prediction of casualties receiving blood. In this population of trauma patients, noninvasive SpHb monitoring, including both trends and absolute values, did not enhance the ability to predict the need for blood transfusion.

Safety, pharmacokinetics, pharmacogenomics and QT concentration-effect modelling of the SirT1 inhibitor selisistat in healthy volunteers.

Selisistat (SEN0014196), a first-in-class SirT1 inhibitor, is being developed as a disease-modifying therapy for Huntington's disease. This first-in-human study investigated the safety, pharmacokinetics and pharmacogenomics of single and multiple doses of selisistat in healthy male and female subjects. In this double-blind, randomized, placebo-controlled study, seven cohorts of eight subjects received a single dose of selisistat at dose levels of 5, 25, 75, 150, 300 and 600 mg and four cohorts of eight subjects were administered 100, 200 and 300 mg once daily for 7 days. Blood sampling and safety assessments were conducted throughout the study. Selisistat was rapidly absorbed and systemic exposure increased in proportion to dose in the 5-300 mg range. Steady-state plasma concentrations were achieved within 4 days of repeated dosing. The incidence of drug related adverse events showed no correlation with dose level or number of doses received and was comparable with the placebo group. No serious adverse events were reported and no subjects were withdrawn due to adverse events. There were no trends in clinical laboratory parameters or vital signs. No trends in heart rate or ECG parameters, including the QTc interval and T-wave morphology, were observed. There were no findings in physical or neurological examinations or postural control. Transcriptional alteration was observed in peripheral blood. Selisistat was safe and well tolerated by healthy male and female subjects after single doses up to 600 mg and multiple doses up to 300 mg day(-1).