Heart Rate Increment Research Articles

The importance of heart rate on left ventricular global longitudinal strain in echocardiography: novel insights facilitated by automated deep learning methods

Abstract Background Heart rate (HR) is assumed to influence echocardiographic measurements. Consequently, HR needs to be considered for accurate assessment of cardiac function. Despite left ventricular global longitudinal strain (LV GLS) being recognised as a valuable measure of cardiac function, its normal reference ranges remain confined to patients within a limited range of resting HR. So far, time-consuming manual analyses and high measurement variability have precluded comprehensive assessment of the interplay between HR and LV GLS. Using fully automated GLS measurements provided by novel deep learning (DL) methods, it is now possible to evaluate changes in LV GLS across a wide range of HR. Purpose To improve echocardiographic assessments across a wide range of HR intervals, we aimed to study the influence of controlled HR variations on LV GLS using programmable pacemakers and fully automated DL measurements. Methods Participants with sinus node dysfunction and implanted programmable pacemakers were enrolled. Echocardiographic acquisitions were obtained at baseline HR and during stepwise increments by 10 beats/min, targeting a range from 50 to 140 beats/min. Recordings of cine-loops including 10 cardiac cycles were obtained for the four-chamber, two-chamber, and apical long axis view. LV GLS was measured for all cycles using a fully automated DL method developed by our group, and presented as mean of the three standard apical views for all patients at each HR level. A linear mixed model was used for construction of an overall trendline based on the estimated fixed effects across all 50 patients, stating patient number as the random effect. The correlation between HR and LV GLS was evaluated by a likelihood ratio test. Results Fifty patients were included, 52% females, mean age 68 years (27 to 88 years). All patients had preserved atrioventricular conduction. Resting HR ranged from 50 to 87 beats/min (mean 64 beats/min). At baseline echocardiographic acquisition, most participants were within normal ranges for LV volumes, systolic and diastolic function. A total of about 13,000 cardiac cycles were automatically analysed by the DL method. The overall trend demonstrated a linear relation between increasing HR and decreasing absolute LV GLS (Figure 1). Across HR increments from 50 to 140 beats/min, there was a 32% (22%–42%) reduction in absolute LV GLS, declining from -17.1% to -11.7%. The strong correlation between changes in HR and LV GLS was further supported by a highly significant likelihood ratio test (p-value <0.001). Conclusions There was a reduction of absolute LV GLS with increasing HR. These findings emphasize the importance of integrating HR considerations into clinical echocardiography practice. Moreover, the results highlight that DL methods can unlock substantially richer insights from individual patient data, offering a new pathway towards more personalized and precise cardiac diagnostics.Figure 1

Proportional increment of oxygen consumption, heart rate and core body temperature in the digesting Python bivittatus.

The Burmese python has a remarkable digestive physiology with large elevations of metabolic rate and heart rate following feeding. Here, we investigated the relationship between heart rate, oxygen consumption and core body temperature during digestion in five pythons (Python bivittatus) by implantation of data loggers. The snakes were placed in respirometers at 30±0.1°C for 26 days and voluntarily ingested three meals of different size, whilst heart rate, core body temperature and oxygen consumption rate were measured continuously. Both oxygen consumption and heart rate increased severalfold during digestion, and metabolic heat production increased core body temperature by 2°C, explaining 12% of the observed tachycardia. The rise in core body temperature means that standard metabolic rate increased during digestion, and we estimate that failure to account for core body temperature leads to a 4% overestimation of the specific dynamic action (SDA) response. Our study reveals a close correlation between oxygen consumption and heart rate during digestion, further supporting the use of heart rate as a proxy for metabolism.

Simulation of loading and unloading through ramps of different configuration: effects on the ease of handling and physiological response of pigs of two slaughter weights

Behaviour, heart rate (HR) and blood lactate concentration of 144 pigs, equally distributed into lighter (L, 122 kg on average) and heavier (H, 153 kg on average) groups, were assessed to study the effects of slaughter weight on pigs’ response to a simulated loading and unloading procedure using four ramp configurations, i.e., 0º (level ramp), 15º slope and 1.66 m length, 15º slope and 2.71 m length (15ºLO), and 25º slope and 1.66 m. No interaction was found between ramp configuration and slaughter weight (P > 0.10). The frequencies of pigs’ slips or falls (P = 0.01) increased on sloped ramps compared to the floor level (Padj < 0.05), and pigs jumped-off more from the 25° than the 15°LO ramp (Padj = 0.05). Pigs negotiating the 25° slope ramp presented a higher concentration of blood lactate than those walking at the floor level (P = 0.02). When compared to L pigs, H pigs were more reluctant to move (P = 0.05) and, presented higher increments of HR (ΔHR) during handling (P = 0.03). In conclusion, heavier pigs were more difficult to handle, regardless of the ramp steepness, which alone reduced ease of handling and affected the physiological condition of pigs.

Effectiveness of facilitated tucking on reducing pain during heel stick in neonates: a randomized controlled experimental study.

Pain in neonates is associated with adverse neurodevelopmental outcomes in the later days of life. Facilitated tucking is a nonpharmacological method of pain relief. The study aims to compare the effect of facilitated tucking in pain reduction in neonates. This was a randomized controlled experimental study conducted in the neonatal ward of a tertiary care center. There were 25 neonates randomized each in the experimental and control groups (total of 50), based on computer-generated random tables. The experimental group was placed in a facilitated tucking position during heel stick, while the control group was kept in the usual position, as done routinely. A self-structured questionnaire and Neonatal Infant Pain Scale were used. The main outcome measures were the mean Neonatal Infant Pain Scale score, and change in preprocedure and postprocedure heart rate and oxygen saturation in the two groups. Ethical clearance and informed written consent were sought. Neonates in the experimental group had significantly lesser pain (less Neonatal Infant Pain Scale score) than the neonates in the control group (P<0.001). There was also a significant increment in the mean heart rate and a decrease in the oxygen saturation after the procedure in the control group, indicating significantly more pain perception (P<0.001) in the control group. Facilitated tucking was found to be effective in reducing the pain during heel stick procedures in neonates.

Differential and synergistic effects of left and right atrial ablation of paraseptal ganglionated plexuses in a cohort of consecutive patients undergoing cardioneuroablation

Abstract Background Cardioneuroablation (CNA) treats reflex syncope by ablating the main epicardial ganglionated plexuses (GPs) conveying vagal outputs to the sino-atrial (SA) and atrio-ventricular (AV) nodes. The two main GPs, superior paraseptal (SPSGP) and inferior paraseptal (IPSGP), regulate vagal tone to SA and AV nodes, respectively. Both GPs can be targeted with radiofrequency energy (RF) from the right (RA) and left atrium (LA). It is unclear if bi-atrial ablation yields more effective GP ablation or if the ablation sequence affects GP response. Purpose We aimed to assess the added efficacy of ablating the SPSGP and IPSGP in the LA after initial RA ablation, and vice versa, in a separate group of patients. Methods In a consecutive patient population undergoing CNA we evaluated the acute efficacy of RF delivery on the SPSGP and the IPSGP. The population was divided into two consecutive groups: one receiving RF initially in the RA and then in the LA (group 1), and the other in the reverse order (group 2). The acute effect of RF applications was measured as percentage increase in heart rate (HR) for the SPSGP and as reduction of PR interval for the IPSGP. Results Sixty-one patients (50±15 years; 61% males) underwent CNA. Of these, 17 underwent ablation of the SPSGP and IPSGP starting from the RA and completing the procedure in the LA (group 1), while in 44 patients, the procedure was performed in the opposite order (group 2). In group 1, RF delivery on the SPSGP from the RA prompted an increase in HR (54.1±11.1 vs 60.6±14.7 bpm; p=0.03; median HR increment 3.8%, IQR 0-38.3) that was further enhanced after LA ablation (from 57.5±11.9 to 64.5±13.5 bpm; p&amp;lt;0.001; median HR increment: 8.0%, IQR: 2.0-13.5). In group 1, RA ablation of the IPSGP reduced PR interval in a single patient (from 224 to 184 ms), without further shortening after LA ablation. Final CNA success was 82% in group 1. In group 2, RF delivery on the SPSGP from the LA induced a marked increase in HR (58.4±13.1 vs 76.8±16.1 bpm; p&amp;lt;0.001; median HR increase 30.0%, IQR 14.0-43.0). In the same patients, additional ablation from the RA prompted further but lower incremental effect (from 70.0±17.3 to 76.9±17.9 bpm; p&amp;lt;0.001; median HR increment 8.3%, IQR: 0-16.4). In group 2, 4 (9%) patients had PR shortening after LA ablation of the IPSGP (241±93 vs 172±14 ms; p value). Of these, a single patient had further PR reduction after IPSGP RA ablation (from 189 to 161 bpm). Final CNA success was 93% in group 2. Symptoms-free survival was 88% at 16±5 months in group 1 and 89% at 19±7 months in group 2 (p= ns). Conclusions Bi-atrial ablation of the SPSGP and IPSGP provides incremental acute efficacy compared to ablation from either the RA or the LA alone. LA ablation of the main GPs seems an essential component of CNA. The physiological significance of these findings requires further investigationGanglionated Plexuses Segmentation

BRASH syndrome with a complete heart block- a case report

IntroductionBRASH syndrome (Bradycardia, Renal failure, Atrioventricular (AV) nodal blocking agent, Shock and Hyperkalemia) is a recently emerging diagnosis that describes the profound bradycardia seen in patients on AV nodal blockers who present with acute kidney injury (AKI) and hyperkalemia.Case presentationWe present a case of a 68 years old female patient with past history of hypertension taking atenolol and Enalapril presented to emergency department with the complaint of loss of consciousness of 02 hours duration. She had 03 days history of fatigue, poor oral intake, decreased urine output, appetite loss, vertigo and global headache. Her vital signs were blood pressure of 60/40 mmHg, absent radial pulse and temperature of 36.4 °C. Her systemic examination was remarkable for dry buccal mucosa; apical heart rate was 22 beats per minute. Glasgow Coma Scale was 13/15. Her laboratory tests showed creatinine of 1.83 mg/dL, blood urea nitrogen of 89 mg/dL and potassium elevated to the level of 6.39 mEq/dL. ECG revealed complete heart block with a normal QT interval and T waves and no U waves with ventricular rate of 22 beats per minute. Her previous medications were discontinued and the patient was resuscitated with intravenous (IV) fluids. She was given 03 doses of 1 mg atropine every 5 minutes but there was no increment in heart rate. She was given 50% dextrose with 10 international units of regular insulin, 1 g of calcium gluconate and Intravenous perfusion of norepinephrine and dopamine. Subsequently, after 14 hours of ICU admission the patient had a cardiac arrest with asystole and resuscitation was attempted but she couldn’t survive.ConclusionBRASH syndrome is largely an under-recognized life threatening clinical diagnosis. Physicians should have high index of suspicion for BRASH when they encounter patients with bradycardia, hyperkalemia, and renal failure, as timely diagnosis is crucial in the management.

Anticipatory Heart Rate Before Moderate- and Vigorous-Intensity Exercise Among Sedentary and Physically Active Young Adult Males.

Background Anticipatory heart rate (HR) refers to an increase in HR that occurs in anticipation of a future event or activity. The anticipatory heart rate (HR) response before exercise is an important physiological indicator of exercise readiness. This study aimed to compare the anticipatory HR changes between sedentary and physically active young adult males during moderate- and vigorous-intensity exercise. Understanding these anticipatory heart rate patterns can provide insights into the physiological adaptations and cardiovascular health of individuals with varying physical activity levels. Materials and methods A total of 60 young adult males, comprising sedentary (n = 30) and physically active individuals (n = 30), participated in this study. A brisk walking for a distance of 50 m was considered moderate intensity and one minute of spot jogging at maximum effort with verbal encouragement was considered vigorous intensity exercise. The HR was recorded at baseline, just before the exercise, and on each minute up to 5 minutes after the exercise. Results The study involved 30 physically active young adult males (mean age 20.23 ± 1.43 years) and 30 sedentary adult males (mean age 20.07 ± 1.17 years). In physically active young adults, the resting HR was 76.4±10.89 bpm and just before starting moderate-intensity exercise, it was 78.83±12.98 bpm, paired t-test P = 0.22. The HR just before vigorous-intensity exercise was 80.83±11.18 bpm (paired t-test P = 0.03). In sedentary young adults, the resting HR was 82.23±12.69 bpm and just before starting moderate-intensity exercise, it was 90.13±18.69 bpm, paired t-test P = 0.0008. The HR just before vigorous-intensity exercise was 91.7±15.04 bpm (paired t-test P <0.0001). Conclusion Physically active young adults did not exhibit a significant increase in anticipatory HR before moderate-intensity exercise. However, sedentary individuals exhibit a significant anticipatory HR response. Before vigorous-intensity exercise, both exhibited significant increments in HR. The result highlights the importance of considering the anticipatory HR response as a potential marker of cardiovascular health and exercise readiness.

Cardiometabolic sex differences in adults born small for gestational age.

This study aimed to assess the cardiometabolic sex similarities and differences in adults born small for gestational age. This study was an ambispective cohort study from a birth registry in Barcelona, Spain, including 523 adult participants (20-40 years-old) subdivided as born small for gestational age (SGA, if birth weight <10th centile) or adequate fetal growth for gestational age (AGA). Cardiometabolic health was assessed by echocardiography, electrocardiogram, blood pressure measurement, vascular ultrasound, anthropometric measurements, and serum glycemia and lipid profile. Stratified analyses by sex were performed by estimation of adjusted absolute difference (AAD) using inverse probability weighting. Compared with AGA, the stratified analyses by sex showed a more pronounced reduction in ejection fraction [AAD: female -1.73 (95% CI -3.2 to -0.28) vs. male -1.33 (-3.19 to 0.52)] and increment in heart rate [female 3.04 (0.29-5.8) vs. male 2.25 (-0.82 to 5.31)] in SGA females compared with SGA males. In contrast, a more pronounced reduction in PR interval [female -1.36 (-6.15 to 3.42) vs. male -6.61 (-11.67 to -1.54)] and an increase in systolic blood pressure [female 0.06 (-2.7 to 2.81) vs. male 2.71 (-0.48 to 5.9)] and central-to-peripheral fat ratio [female 0.05 (-0.03 to 0.12) vs. male 0.40 (0.17-0.62)] were mainly observed in SGA male compared with SGA female. Sex differences were observed in the effect of SGA on cardiometabolic endpoints with female being more prone to cardiac dysfunction and male to electrocardiographic, vascular, and metabolic changes. Future research including sex-stratification data is warranted.

A Pacing-Controlled Procedure for the Assessment of Heart Rate-Dependent Diastolic Functions in Murine Heart Failure Models.

Heart failure with preserved ejection fraction (HFpEF) is a condition characterized by diastolic dysfunction and exercise intolerance. While exercise-stressed hemodynamic tests or MRI can be used to detect diastolic dysfunction and diagnose HFpEF in humans, such modalities are limited in basic research using mouse models. A treadmill exercise test is commonly used for this purpose in mice, but its results can be influenced by body weight, skeletal muscle strength, and mental state. Here, we describe an atrial-pacing protocol to detect heart rate (HR)-dependent changes in diastolic performance and validate its usefulness in a mouse model of HFpEF. The method involves anesthetizing, intubating, and performing pressure-volume (PV) loop analysis concomitant with atrial pacing. In this work, a conductance catheter was inserted via a left ventricular apical approach, and an atrial pacing catheter was placed in the esophagus. Baseline PV loops were collected before the HR was slowed with ivabradine. PV loops were collected and analyzed at HR increments ranging from 400 bpm to 700 bpm via atrial pacing. Using this protocol, we clearly demonstrated HR-dependent diastolic impairment in a metabolically induced HFpEF model. Both the relaxation time constant (Tau) and the end-diastolic pressure-volume relationship (EDPVR) worsened as the HR increased compared to control mice. In conclusion, this atrial pacing-controlled protocol is useful for detecting HR-dependent cardiac dysfunctions. It provides a new way to study the underlying mechanisms of diastolic dysfunction in HFpEF mouse models and may help develop new treatments for this condition.

Spontaneous physical functional recovery after hospitalization for COVID-19: insights from a 1 month follow-up and a model to predict poor trajectory.

Long COVID syndrome has emerged as a new global healthcare challenge, with impaired physical performance being a prominent debilitating factor. Cardiopulmonary rehabilitation is a mainstay of management of symptomatic post-COVID patients, and optimization of candidate selection might allow for more effective use of available resources. In order to study the natural dynamics and to identify predictors of physical functional recovery following hospitalization for COVID-19, 6 min walk test was performed pre-discharge in 176 patients (40% hypertensive, 53% female, mean age 53.2 ± 13.5 years) with re-evaluation at 1 month. Six min walk distance and the reached percent of predicted distance (6MWD%) were suboptimal at both visits-396 ± 71 m (68.7 ± 12.4%) pre-discharge and 466 ± 65 m (81.8 ± 13.6%) at 1 month. Associated changes included significant oxygen desaturation (2.9 ± 2.5 and 2.3 ± 2.2%, respectively) and insufficient increment of heart rate during the test (24.9 ± 17.5 and 28.2 ± 12.0 bpm) that resulted in low reached percent of individual maximum heart rate (61.1 ± 8.1 and 64.3 ± 8.2%). Automatic clusterization of the study cohort by the 6MWD% changes has allowed to identify the subgroup of patients with poor "low base-low increment" trajectory of spontaneous post-discharge recovery that were characterized by younger age (38.2 ± 11.0 vs. 54.9 ± 12.1, p < 0.001) but more extensive pulmonary involvement by CT (43.7 ± 8.8 vs. 29.6 ± 19.4%, p = 0.029) and higher peak ESR values (36.5 ± 9.7 vs. 25.6 ± 12.8, p < 0.001). Predictors of poor recovery in multivariate logistic regression analysis included age, peak ESR, eGFR, percentage of pulmonary involvement by CT, need for in-hospital oxygen supplementation, SpO2 and mMRC dyspnea score pre-discharge, and history of hypertension. COVID-19 survivors were characterized by decreased physical performance pre-discharge as assessed by the 6 min walk test and did not completely restore their functional status after 1 month of spontaneous recovery, with signs of altered blood oxygenation and dysautonomia contributing to the observed changes. Patients with poor "low base-low increment" trajectory of post-discharge recovery were characterized by younger age but more extensive pulmonary involvement and higher peak ESR values. Poor post-discharge recovery in the study cohort was predictable by the means of machine learning-based classification model that used age, history of hypertension, need for oxygen supplementation, and ESR as inputs.

Predicting Therapeutic Efficacy of Pharmacological Treatments in Children with Postural Orthostatic Tachycardia Syndrome: A Mini-Review.

Postural orthostatic tachycardia syndrome (POTS) is common in children, with an excessive increment in heart rate when moving from the supine to upright position. It has significant negative impacts on the daily life of pediatric patients. The pathogenesis of POTS includes peripheral vascular dysfunction, central hypovolemia, abnormal autonomic function, a high-adrenergic state, impaired skeletal-muscle pump function, the abnormal release of vasoactive factors, and autoimmune abnormalities. Therefore, the empirical use of pharmacological treatments has limited therapeutic efficacy due to the diversity of its mechanisms. A crucial aspect of managing POTS is the selection of appropriate treatment targeting the specific pathogenesis. This review summarizes the commonly used pharmacological interventions, with a focus on their predictive indicators for treatment response. Factors such as heart rate variability, plasma biomarkers, and cardiac-function parameters are discussed as potential predictors of therapeutic efficacy, enabling the implementation of individualized treatment to improve therapeutic effectiveness. This review consolidates the current knowledge on POTS, encompassing its clinical characteristics, epidemiological patterns, underlying pathogenic mechanisms, and predictive indicators for treatment response. Further research is warranted to enhance the understanding of POTS and facilitate the development of more effective therapeutic approaches for this challenging syndrome.

Improvement of students’ physical fitness in physical education classes using CrossFit means

Background and Study Aim. The purpose of the study is to develop and experimentally substantiate the efficiency of methods to improve the physical fitness (PF) of students in physical education classes using CrossFit means. Material and Methods. The studies were conducted at the University with first-year students and involved 44 students of the control group and 52 students of the experimental group aged 17 to 19 years. Three versions of the experimental program to improve the students’ PF in physical education classes using CrossFit means were developed. The students’ PF level was determined according to the results of performing the State tests of the Ministry of Education and Science of Ukraine: 100 m running (s), standing long jump (cm), pull-ups and cross bar dips (number); hanging leg raises to the crossbar (number); 1000 m running (min, s); shuttle run 4x9 m and 10x10 m (s); trunk forward bending (cm). The level of students’ functional fitness was determined according to the indices of heart rate (HR), blood pressure, time of breath-holding while performing Stange’s test, lung vital capacity. Results. In the process of the pedagogical experiment more pronounced positive changes in the indices of physical and functional fitness were observed in students of the experimental group as compared to those of the control group, the functional reserves of the heart and motor system of students increased by the end of the experiment. The efficiency of four-hour classes a week according to the experimental program manifested itself in the increase of strength, strength endurance, speed and agility during a performance of motor tests; a decrease in resting heart rate, an increase of the degree of HR increment under load (relative to the resting level), an increase of HR recovery at the first minute after the load. Mathematical models of interrelations of separate somatic and vegetative parameters in the process of development and improvement of motor skills under the influence of the experimental program of physical education with the use of CrossFit means were developed and specified. Mathematical models reflect mechanisms of increase of functional reserves of heart and motor system of students, their interrelation in the process of improving the results in motor tests under the influence of CrossFit means. Conclusions. The results of the research confirm the higher efficiency of the physical education experimental method with the use of specially developed complexes of CrossFit® physical exercises in comparison with the generally accepted program of the Ministry of Education and Science of Ukraine. The efficiency of the experimental program’s impact on the physical state of the students is confirmed by an increase in the level of development of motor qualities, an increase in the economy of the body functioning at rest, an increase in the functional reserves of the heart and the motor system.

Long-Term Outcome of Cardiac Denervation Procedures: The Anatomically Guided Septal Approach

BackgroundFunctional bradycardia is a challenging condition that affects a healthy population. Ganglionated plexus ablation has emerged as a therapeutic alternative to avoid a pacemaker. ObjectivesThe purpose of this study is to evaluate long-term effects of anatomically guided cardiac denervation. MethodsThis is a prospective longitudinal study that included 36 patients with symptomatic functional bradycardia. Electroanatomic reconstruction of both atria was carried out, and the main septal ganglionated plexi were anatomically located and targeted. ResultsAblation endpoints were: 1) heart rate increment; 2) Wenckebach cycle length shortening; and 3) atrio-Hisian (AH) interval shortening. A sinus node denervation was obtained in all patients with an increment of 21.6% in the mean heart rate. All patients presented a negative atropine test after ablation. Twenty-eight (77.7%) patients presented immediate sings of atrioventricular node denervation, with a shortening of 15.6% of mean Wenckebach cycle length and 15.9% of the mean AH interval. All heart rate variability parameters showed a significant reduction after 12 months, enduring after 18 months. Thirty (83.3%) patients remained free of events after a mean follow-up of 52.1 ± 35.2 months. One patient (2.77%) presented acute sinus node artery occlusion during ablation with persistent sinus dysfunction and had a pacemaker implantation; 3 (8.3%) other patients evolved with sinus tachycardia, and 4 (11.1%) patients presented syncope recurrence during follow-up, 3 (8.3%) of them requiring a pacemaker implantation. No other tachyarrhythmia was observed. ConclusionsThe anatomically guided septal approach is an effective technique for syncope prevention, promoting long-lasting autonomic changes. No significant proarrhythmia effect has been observed during the long-term follow-up.

Effects of temperature control on hyperthermia-related cardiac dysfunction in a porcine model of cardiac arrest

The outcome of cardiac arrest is worse when there is fever after spontaneous circulation is restored (ROSC). The purpose of this study was to investigate the mechanism of post-ROSC cardiac dysfunction after hyperthermia treatment and the effects of temperature control. Twenty-four male Bama minipigs were randomized into 3 groups (8 per group): CPR + controlled normothermia (CN), CPR + hyperthermia (HT), and CPR + therapeutic mild hypothermia (TMH). Defibrillation was given to pigs with ventricular fibrillation after 8 min of untreated fibrillation. Subsequently, these animals received the post-ROSC treatments of hyperthermia (38 °C), controlled normothermia (37 °C) or hypothermia (33 °C) according to the groups. Hemodynamic parameters, left ventricular ejection fraction, blood samples and myocardial tissues were assessed. At 24 h after the post-ROSC treatments, the pigs treated with hyperthermia showed increments in heart rate and plasma cardiac troponin I, and decreases in mean arterial pressure, cardiac index, and left ventricular ejection fraction, compared to those with the controlled normothermia pigs. However, the deterioration of the above parameters can be attenuated by TMH. The pigs in the TMH group also had a reduced percentage of apoptotic cardiomyocytes, an increased anti-apoptotic Bcl-2/Bax ratio and a decreased caspase-3 activity in myocardium, as compared with both controlled normothermia and hyperthermia pigs. In conclusion, hyperthermia is associated with a worse myocardial dysfunction. TMH improves hyperthermia-induced myocardial dysfunction by attenuating apoptosis in a porcine model of cardiac arrest.

A Methodical Approach to Scrutinize the Role of Body Mass Index in Heart Rate Increment and Recovery

OBJECTIVES Heart rate (HR) is a crucial health indicator and is also one of the health factors we need to pay explicit attention to. Body Mass Index (BMI) is considered a cofactor in heart-related issues like heart rate increment and recovery. Thus a study was conducted to determine the relationship between BMI and the rate of heart rate increment and recovery. METHODOLOGY 24 participants aged 17-20 were examined during elliptical machine training once a week continuously for three months. Their regular resting heart rate and change in heart rate during and after the elliptical workout were recorded and compared with BMI. RESULTS The HR increments were noted alongside BMI for male participants below BMI 21.13, and female participants below BMI 20.16. The heart rate increment tempo decreases alongside the increased BMI for both sexes afterwards. The heart rate recovery (HRrecovery) for male participants falls with the BMI increase to ~25 and increases thereafter. The female participants show a differing trend: HRrecovery rates increase following BMI growth till BMI ~ 20 and then decrease parabolically till the maximum BMI among female participants. The findings suggest no linear and non-significant correlation between BMI and heart rate increment or HRrecovery. The coefficient of determination is too tiny (R2 = 0.1395 for males and R2 = 0.003 for females) to indicate the causation between BMIs and HRrecovry. CONCLUSION This is the first study scrutinizing the role of body mass index on heart rate increment and heart rate recovery. Thus BMI should not be used as the cofactor or risk for heart activity or impaired functions.

Reliability and Sensitivity of Nocturnal Heart Rate and Heart-Rate Variability in Monitoring Individual Responses to Training Load.

To assess the reliability of nocturnal heart rate (HR) and HR variability (HRV) and to analyze the sensitivity of these markers to maximal endurance exercise. Recreational runners recorded nocturnal HR and HRV on nights after 2 identical low-intensity training sessions (n = 15) and on nights before and after a 3000-m running test (n = 23). Average HR, the natural logarithm of the root mean square of successive differences (LnRMSSD), and the natural logarithm of the high-frequency power (LnHF) were analyzed from a full night (FULL), a 4-hour (4H) segment starting 30minutes after going to sleep, and morning value (MOR) based on the endpoint of the linear fit through all 5-minute averages during the night. Differences between the nights were analyzed with a general linear model, and intraclass correlation coefficient (ICC) was used for internight reliability assessments. All indices were similar between the nights followed by low-intensity training sessions. A very high ICC (P < .001) was observed in all analysis segments with a range of .97 to .98 for HR, .92 to .97 for LnRMSSD, and .91 to .96 for LnHF. HR increased (P < .001), whereas LnRMSSD (P < .01) and LnHF (P < .05) decreased after the 3000-m test compared with previous night only in 4H and FULL. Increments in HR (P < .01) and decrements in LnRMSSD (P < .05) were greater in 4H compared with FULL and MOR. Nocturnal HR and HRV indices are highly reliable. Demanding maximal exercise increases HR and decreases HRV most systematically in 4H and FULL segments.

Different Resting Methods in Improving Laypersons Hands-Only Cardiopulmonary Resuscitation Quality and Reducing Fatigue: A Randomized Crossover Study

ObjectiveTo determine the effects of different resting methods with various rest-start points or rest-compression ratios on improving cardiopulmonary resuscitation (CPR) quality and reducing fatigue during continuous chest compressions (CCC) in 10-min hands-only CPR scenario. MethodsThis prospective crossover study was conducted in 30 laypersons aged 18-65. Trained participants were randomized to follow different orders to perform following hands-only CPR methods: (1) CCC, 10-min CCC; (2) 4+6, 4-min CCC + 6-min of 10-s pause after 60-s compressions; (3) 2+8 (10/60), 2-min CCC + 8-min of 10-s pause after 60-s compressions; (4) 5/30, 2-min CCC + 8-min of 5-s pause after 30-s compressions; (5) 3/15, 2-min CCC + 8-min of 3-s pause after 15-s compressions. CPR quality (depth, rate, hands-off duration, chest compression fraction (CCF)) and participants’ fatigue indicators (heart rate, blood pressure, rating of perceived exertion (RPE)) were compared among methods of different rest-start points and different rest-compression ratios with CCC. ResultsTwenty-eight participants completed all methods. All resting methods reduced the trend of declining compression depth and the trend of increasing RPE while maintaining CCF of more than 86%. In methods with different rest-start points, the 2+8 method showed no difference in overall CPR quality or fatigue, but better CPR quality of every minute than 4+6 method. In methods with different rest-compression ratios, the 3/15 method showed the best CPR quality and the highest heart rate increment. ConclusionDuring prolonged hands-only CPR, appropriate transient rests were associated with higher CPR quality and lower subjectively perceived fatigue in laypersons.

An Unusual Case of Polyautoimmunity with Concomitant Presentation of Postural Tachycardia Syndrome, Antiphospholipid Syndrome and Hashimoto’s Thyroiditis

Introduction: Postural tachycardia syndrome (POTS) is a chronic form of autonomic dysfunction characterized by symptoms of orthostatic intolerance, often accompanied by sudomotor dysfunction and gastrointestinal dysmotility. In a subgroup of patients with POTS, autoantibodies against adrenergic or cholinergic receptors suggest an immune-mediated etiology. Antiphospholipid syndrome (APS) is a hypercoagulative autoimmune disorder associated with anti-phospholipid-antibodies that causes arterial and venous thromboses. Concurrent occurrence of APS and immune-mediated POTS is rare. Methods and Results: Here, we report a 28-year-old female that experiences symptoms of orthostatic intolerance, vasovagal syncopes, gastrointestinal dysmotility and sudomotor dysfunction. She fulfills the formal diagnostic criteria of POTS showing a heart rate increment of ≥30 beats per minute (bpm) within 10 m of head-up tilt in the absence of orthostatic hypotension, accompanied by symptoms of orthostatic intolerance. The thermoregulatory sweat test reveals severe patchy anhidrotic areas. Gastric emptying scintigraphy shows an impaired gastrointestinal motility. Plasma norepinephrine levels and a skin biopsy appear normal. Finally, serological persistence of anti-alpha-1-adrenergic autoantibodies suggest an immune-mediated pathogenesis. Several years after initial presentation of POTS symptoms, the patient develops APS with recurrent venous emboli and persistent anti-phospholipid-antibodies. Recently the patient is diagnosed with Hashimoto’s thyroiditis (HT) expressing high levels of thyroid-stimulating hormone and high titers of anti-thyroid antibodies. Conclusion: To our knowledge, this is the first report of consecutive immune-mediated POTS, APS and HT in a young woman, possibly displaying a unique combination of three disorders of autoimmune etiology.

Heart rate variability and incident type 2 diabetes mellitus

Abstract Background Hyperglycemia and autonomic dysfunction are bidirectionally related. The implications from former cross-sectional studies regarding the association of autonomic dysfunction and diabetes are limited due to the potential reverse causation. We aimed to investigate the association of longitudinal evolution of heart rate variability (HRV) with incident type 2 diabetes mellitus (T2D) among the general population. Methods Using data from the prospective population-based cohort study, 7630 participants with available repeated assessments of HRV, who were free of T2D and atrial fibrillation, were included. Measurements of HRV were analyzed from standard 10-s electrocardiograms records, including heart rate and two time-domain HRV markers: the heart-rate corrected standard deviation of the normal-to-normal RR intervals (SDNNc) and heart-rate corrected root mean square of successive RR-interval differences (RMSSDc). Joint models with the Bayes approach were performed to assess the associations between longitudinal evolutions of heart rate and different HRV metrics with incident T2D during follow-up. Models were adjusted for age, sex, body mass index, smoking status, systolic blood pressure, total and high-density lipoprotein cholesterol, use of blood pressure-lowering or lipid-lowering medication, and prevalent cardiovascular disease. Spearmen correlation was used to examine the associations between HRV metrics and glycemic traits (fasting blood glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β)) at baseline. Results During a median follow-up time of 8.6 years, 871 individuals developed T2D. Based on joint models, one standard deviation (SD) increment of heart rate (hazard ratio [HR], 1.21; 95% CI, 1.09–1.34), log(SDNNc) (HR, 1.10; 95% CI, 0.94–1.27), and log(RMSSDc) (HR, 1.15; 95% CI, 1.02–1.31) was associated with the risk of developing T2D in fully-adjusted models. Subgroup analyses suggested stronger associations among men. The HRs of incident T2D per SD increment were 1.25 (1.09, 1.43) for men and 1.16 (0.99, 1.35) for women for heart rate, 1.23 (1.01, 1.51) for men and 0.97 (0.78, 1.20) for women for log(SDNNc), and 1.24 (1.05, 1.48) for men and 1.09 (0.89, 1.31) for women for log(RMSSDc). Results did not change after excluding participants who were prediabetes at baseline or after exclusion of underweight participants. Spearmen correlation indicated that heart rate was significantly associated with baseline glycemic traits, while RMSSDc was only related to fasting blood glucose. Conclusion Our study suggests that both higher heart rate and heart rate variability are associated with an increased risk of T2D development, especially among men. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Erasmus MC and Erasmus University Rotterdam; Netherlands Organization for Scientific Research; Netherlands Organization for Health Research and Development (ZonMw); Research Institute for Diseases in the Elderly; Netherlands Genomics Initiative; Netherlands Ministry of Education, Culture and Science; Netherlands Ministry of Health, Welfare and Sports; European Commission; and Municipality of Rotterdam. We would like to thank the China Scholarship Council for the scholarship to K.W. Forest plot

Safety of airway clearance combined with bronchodilator and hypertonic saline in non-hospitalized infants with acute bronchiolitis

Background: Acute viral bronchiolitis (AVB) is associated with significant morbidity and no study has addressed the safety of airway clearance techniques (ACT) for non-hospitalized infants. This study aimed to evaluate the safety of the use of ACT combined with bronchodilator and hypertonic saline in non-hospitalized children with the first episode of AVB. Methods: A quasi-experimental study of infants aged 2–12 months, with a clinical diagnosis of AVB (mild to moderate), was performed. The Wang score, breathing frequency, oxygen saturation (SpO2), heart rate (HR), and the presence of adverse events were evaluated before, 10 and 20 min after the application of a protocol including ACT (nasal irrigation, prolonged slow expiration, and provoked cough), bronchodilator and hypertonic saline inhalation. A total of 265 infants, mean age 6.86±3.01 months, were included. Results: A reduction (p<0.001) in the Wang score and in the breathing frequency as well as an increase in SpO2 were found. There was also a transient HR increment at 10 min followed by a reduction at 20 min (p<0.05). The proportion of patients presenting with chest retraction and wheezing decreased (p<0.001) after treatment. Most of the children (88.3%) did not experience adverse events. A post-treatment increment (p<0.001) of patients classified as having normal values, as well as a decrease in those with mild and moderate AVB, was found for the Wang score levels. Conclusion: The use of ACT combined with bronchodilator and hypertonic saline was safe, immediately after treatment, for non-hospitalized children with mild to moderate AVB. No clinically important deterioration or adverse events were identified in the follow-up period.