Determining target heart rate for exercising in a cardiac rehabilitation program: a retrospective study

Evaluating the influence of ambient conditions in the cooking space of railway pantry car using selected thermal indices and physiological parameter

BACKGROUND

Hot and humid indoor environment of the kitchen affects worker performance. The Indian Railway's pantry car culinary is one of them that cooks food for the on-board passengers, which could be bothered by the hot indoor climate.

OBJECTIVE

The current study aimed to identify the indoor working environment of the railway "pantry car" using heat stress indices such as "Universal Thermal Climate Index-UTCI," "Wet-Bulb Globe Temperature-WBGT," "Discomfort Index-DI," "Tropical Summer Index-TSI," "Heat Index-HI," and Heart Rate-HR with clothing insulation. METHODS: The study was performed in 2018 (August-summer season) to collect field survey data on 6 railway pantry cars. Measurements were carried out during peak cooking times such as morning "7 : 00 am", day "11 : 30 am", evening "4 : 00 pm," and night "6 : 30 pm". This study's descriptive and Pearson's correlation analysis was accomplished using SPSS version 2016 software.

RESULTS

The analysis results revealed that the average values were for UTCI (37.77±5.26°C), WBGT (30.42±2.28°C), DI (30.05±2.70°C), TSI (33.21±2.90°C), HI (48.53±4.86°C), correspondingly. During analysis, the strongest correlation association was observed between "TSI and DI" (r = 0.985, p < 0.000) and WBGT and TSI (r = 0.958, p < 0.000). A "significant correlation" was found between UTCI and HI (r = 0.637, p < 0.05). While no signification correlation was found between "heat stress indices and physiological parameters (p > 0.05)".

CONCLUSION

In this study, all the heat stress index limit values showed highly harsh working conditions inside the pantry car, which created unfavorable circumstances for the culinarians. Inappropriate "ventilation design" could be a reason for discomfort in the railway pantry car.

Effectiveness of kneeling training in improving mobility and balance post-stroke

BACKGROUND

Fall prevention and balance control constitute critical components of rehabilitation for stroke survivors. Kneeling training, characterized by its low center of gravity focus, has been incorporated into rehabilitation regimens to enhance postural control across various pathological conditions. Despite its widespread use, empirical evidence substantiating the efficacy of kneeling training is limited, particularly in the context of mobility and balance improvement for patients who have had a stroke. This study aims to substantiate the safety and effectiveness of kneeling training in individuals recovering from stroke.

METHODS

A randomized controlled trial comparing kneeling training and conventional rehabilitation training was conducted, involving sixty-seven participants allocated to the Kneeling Training Group (KNT) and the Conventional Rehabilitation Group (CVR). The KNT group underwent 30-minute sessions of kneeling training, while the CVR group received conventional treadmill walking training, both administered six times per week over four weeks. Evaluation encompassed the Fugl-Meyer Assessment for Lower Extremity (FMA-LE), the Berg Balance Scale (BBS), and gait analysis was conducted at baseline, as well as at the 2 and 4-week intervals.

RESULTS

Our study established the safety of a 4-week kneeling training program. Notably, the KNT group exhibited more pronounced improvements in BBS scores at weeks 2 and 4 compared to the CVR group. However, no significant disparities emerged in FMA-LE and gait analysis between the two groups. Our findings suggest that kneeling training may serve as a viable option for enhancing lower limb balance in survivors who have had a stroke.

CONCLUSIONS

We conclude that kneeling training, characterized by its safety, simplicity, and no restrictions on location or equipment, represents a valuable therapeutic approach for enhancing walking balance in individuals recovering from stroke.

TRIAL REGISTRATION

Clinical trials ChiCTR1900028385, December 20, 2019.

Among Patients Taking Beta-Adrenergic Blockade Therapy, Use Measured (Not Predicted) Maximal Heart Rate to Calculate a Target Heart Rate for Cardiac Rehabilitation

PURPOSE

Among patients in cardiac rehabilitation (CR) on beta-adrenergic blockade (βB) therapy, this study describes the frequency for which target heart rate (THR) values computed using a predicted maximal heart rate (HR max ), correspond to a THR computed using a measured HR max in the guideline-based heart rate reserve (HR reserve ) method.

METHODS

Before CR, patients completed a cardiopulmonary exercise test to measure HR max , with the data used to determine THR via the HR reserve method. Additionally, predicted HR max was computed for all patients using the 220 - age equation and two disease-specific equations, with the predicted values used to calculate THR via the straight percent and HR reserve methods. The THR was also computed using resting heart rate (HR) +20 and +30 bpm.

RESULTS

Mean predicted HR max using the 220 - age equation (161 ± 11 bpm) and the disease-specific equations (123 ± 9 bpm) differed ( P < .001) from measured HR max (133 ± 21 bpm). Also, THR computed using predicted HR max resulted in values that were infrequently within the guideline-based HR reserve range calculated using measured HR max . Specifically, 0 to ≤61% of patients would have had an exercise training HR that fell within the guideline-based range of 50-80% of measured HR reserve . Use of standing resting HR +20 or +30 bpm would have resulted in 100% and 48%, respectively, of patients exercising below 50% of HR reserve .

CONCLUSIONS

A THR computed using either predicted HR max or resting HR +20 or +30 bpm seldom results in a prescribed exercise intensity that is consistent with guideline recommendations for patients in CR.

Consistency evaluation of exercise target heart rate determined by resting heart rate and anaerobic threshold in chronic heart failure patients

PURPOSE

To evaluate the consistency on the target heart rate for exercise determined by simple target heart rate (sTHR) based on resting heart rate (HRrest) and heart rate at anaerobic threshold (HRAT) in cardiopulmonary exercise test (CPET) for patients with chronic heart failure.

METHODS

This is a retrospective cohort study, in which CHF patients who underwent CPET in Tongji Hospital Cardiac Rehabilitation Center Affiliated to Tongji University from March 2007 to December 2018 were enrolled. The clinical data of the patients from the electronic medical record system, HRrest and HRAT measured by CPET were collected. Patients were further divided into subgroups according to gender, age (<60 years group and ≥ 60 years group), with or without beta-blocker therapy and subgroup of heart failure (heart failure with reduced, mid-range and preserved ejection fraction). The sTHR (HRrest plus 10, 15, 20, 25 and 30 bpm) and HRAT were all calculated in each patient. Paired t-test was used for the difference between the two methods, correlation analysis was shown by pearson analysis and intraclass correlation coefficient (ICC) was calculated for consistency test.

RESULTS

A total of 547 CHF patients were enrolled, including 447 males (81.7%), aged 63 (56,69) years, with BMI of 25.2 (23.5,26.4) kg/m² and LVEF of 45.0 (36.0, 52.0) %. The target heart rate determined by HRAT method was (93.59 ± 13.95) bpm, and its counterpart determined by HRrest plus 20 bpm (HRrest₊₂₀) was (93.16 ± 7.69) bpm. There was no significant difference between the two methods (P>0.05). However, it was statistically different between HRrest plus 10, 15, 25, 30 bpm and HRAT respectively (P<0.001). And HRrest₊₂₀ was positively correlated with HRAT (r = 0.418, P<0.001). Therefore, HRrest₊₂₀ below was regarded as sTHR. The ICC of the consistency test between sTHR and HRAT was 0.523,95%CI 0.435-0.596 (P < 0.001) in all patients (n = 547). In patients with beta-blocker therapy (n = 464), the ICC of sTHR and HRAT consistency test was 0.534,95%CI 0.441-0.612, P < 0.001; The ICC of the consistency test between sTHR and HRAT of patients without beta-blocker therapy (n = 83) was 0.407,95%CI 0.083-0.616, P < 0.05. In the sinus rhythm group (n = 466), the ICC of sTHR and HRAT consistency test was 0.527,95%CI 0.433-0.606, P < 0.001; The ICC of the consistency test between sTHR and HRAT of atrial fibrillation patients in group (n = 81) was 0.482,95%CI 0.195-0.667, P < 0.05.The ICC of the consistency test between sTHR and HRAT was 0.501,95%CI 0.338-0.623 (P < 0.001) in patients under 60 years old (n = 195); The ICC of the consistency test between sTHR and HRAT in patients ≥60 years old (n = 352) was 0.533,95%CI 0.424-0.621, P < 0.001. In the male group (n = 447), the ICC of sTHR and HRAT consistency test was 0.577,95%CI 0.491-0.649, P < 0.001; The ICC of the consistency test between sTHR and HRAT of female patients in group (n = 100) was 0.344,95%CI 0.025-0.559, P < 0.05. The ICC of sTHR and HRAT consistency test in HFrEF group (n = 170) was 0.395,95%CI 0.181-0.553, P < 0.01; The ICC values of the consistency test between sTHR and HRAT was 0.543, 95%CI 0.405-0.649 (P < 0.001) in patients with HFmrEF (n = 222); In HFpEF group (n = 155), the ICC of sTHR and HRAT consistency test was 0.620,95%CI 0.478-0.723, P < 0.001.

CONCLUSION

The exercise target heart rate calculated by HRrest is consistent with that determined by HRAT in patients with CHF. For primary hospitals without CPET, exercise prescription equivalent to AT intensity for patients with CHF can be determined by HRrest. However, the target heart rate calculated by HRrest can't replace that determined by HRAT in this patient cohort completely.

Assessing the Clinical Utility of a Wearable Device for Physiological Monitoring of Heart Rate Variability in Military Service Members with Traumatic Brain Injury

Introduction: Autonomic dysfunction has been implicated as a consequence of traumatic brain injury (TBI). Heart rate variability (HRV) may be a viable measure of autonomic dysfunction that could enhance rehabilitative interventions for individuals with TBI. This pilot study sought to assess the feasibility and validity of using the Zeriscope™ platform system in a real-world clinical setting to measure HRV in active-duty service members with TBI who were participating in an intensive outpatient program. Methods: Twenty-five service members with a history of mild, moderate, or severe TBI were recruited from a military treatment facility. A baseline assessment was conducted in the cardiology clinic where point validity data were obtained by comparing a 5-min recording of a standard 12-lead electrocardiogram (ECG) output against the Zeriscope platform data. Results: Compared with the ECG device, the Zeriscope device had a concordance coefficient (rc) of 0.16, falling below the standard deemed to represent acceptable accuracy in HR measurement (i.e., 0.80). Follow-up analyses excluding outliers did not significantly improve the concordance coefficient to an acceptable standard for the total participant sample. System Usability Survey responses showed that participants rated the Zeriscope system as easy to use and something that most people would learn to use quickly. Conclusions: This study demonstrated promise in ambulatory HRV measurement in a representative military TBI sample. Future research should include further refinement of such ambulatory devices to meet the specifications required for use in a military active-duty TBI population.

Using in-seat electrical potential sensors for non-contact monitoring of heart rate, heart rate variability, and heart rate recovery

Detecting transient changes in heart rate and heart rate variability during experimental simulated autonomous driving scenarios can indicate participant arousal and cognitive load, providing valuable insights into the relationship between human and vehicle autonomy. Successfully detecting such parameters unobtrusively may assist these experimental situations as well as naturalistic driver monitoring systems within an autonomous vehicle. However, non-contact sensors must collect reliable and accurate signals. This study aims to compare the in-seat, non-contact Plessey EPIC sensor to the gold standard, contact Biopac sensor. Thirty participants took part in five-minute simulated autonomous vehicle journeys in a city environment and a rural environment, and a five-minute resting condition. To ensure the seat sensor was sensitive to elevated heart rate values, heart rate was also collected following the energetic Harvard Step Test. Lin concordance coefficients and Bland-Altman analyses were employed to assess the level of agreement between the non-contact Plessey EPIC sensor and the contact Biopac sensor for heart rate and heart rate variability. Analyses revealed a high level of agreement (r_c > 0.96) between both sensors for one-minute averaged heart rate and five-minute averaged heart rate variability during simulated autonomous driving and rest, and one-minute averaged heart rate following the Harvard Step Test. In addition, the non-contact sensor was sensitive to significant differences during tasks. This proof of principle study demonstrates the feasibility of using the non-contact Plessey EPIC sensor to accurately detect heart rate and heart rate variability during simulated autonomous driving environments.

Acute Hemodynamic Improvement by Thermal Vasodilation inside the Abdominal and Iliac Arterial Segments of Young Sedentary Individuals

OBJECTIVE

To study the hemodynamic response to lower leg heating intervention (LLHI) inside the abdominal and iliac arterial segments (AIAS) of young sedentary individuals.

METHODS

A Doppler measurement of blood flow was conducted for 5 young sedentary adults with LLHI. Heating durations of 0, 20, and 40 min were considered. A lumped parameter model (LPM) was used to ascertain the hemodynamic mechanism. The hemodynamics were determined via numerical approaches.

RESULTS

Ultrasonography revealed that the blood flow waveform shifted upwards under LLHI; in particular, the mean flow increased significantly (p < 0.05) with increasing heating duration. The LPM showed that its mechanism depends on the reduction in afterload resistance, not on the inertia of blood flow and arterial compliance. The time-averaged wall shear stress, time-averaged production rate of nitric oxide, and helicity in the external iliac arteries increased more significantly than in other segments as the heating duration increased, while the oscillation shear index (OSI) and relative residence time (RRT) in the AIAS declined with increasing heating duration. There was a more obvious helicity response in the bilateral external iliac arteries than the OSI and RRT responses.

CONCLUSION

LLHI can effectively induce a positive hemodynamic environment in the AIAS of young sedentary individuals.

Feasibility of integrating survivors of stroke into cardiac rehabilitation: A mixed methods pilot study

BACKGROUND

Survivors of stroke are often deconditioned and have limited opportunities for exercise post-rehabilitation. Cardiac Rehabilitation (CR), a structured exercise program offered post-cardiac event in the United States (U.S.), may provide an opportunity for continued exercise. The purpose of this study was to examine the feasibility of integrating survivors of stroke into an existing, hospital-based CR program through an assessment of (1) recruitment, uptake and retention, (2) adherence and fidelity, (3) acceptability and (4) safety.

METHODS

A mixed methods design combined a single group, pre-post design, pilot feasibility study with an imbedded qualitative inquiry. Survivors of stroke were recruited into a standard 12-week, 36 visit CR program.

RESULTS

Fifty-three survivors were referred, 29 started and 24 completed the program. Program uptake rate was 55% and completion rate was 83%. Eleven completers and one non-completer participated in the qualitative interviews. Program completers attended an average of 25.25 (SD 5.82) sessions with an average of 38.93 (SD 5.64) exercise minutes per session while reaching targeted rate of perceived exertion levels. Qualitative themes included perceived benefits of an individualized program in a group setting, positive interactions with qualified staff, opportunities for socialization, and regular monitoring and staff attentiveness promoting feelings of safety.

CONCLUSIONS

Survivors of stroke were able to meet Medicare standard dosage (frequency and session duration) and rate of perceived intensity goals, and perceived the program as needed regardless of their mobility limitations or previous exercise experience. Primary challenges included managing referrals and uptake. Results support feasibility and benefit for survivors to integrate into U.S. CR programs.

ISO/IEEE 11073 Treadmill Interoperability Framework and its Test Method: Design and Implementation

BACKGROUND

Regular physical activity is proven to help prevent and treat noncommunicable diseases such as heart disease, stroke, diabetes, and breast and colon cancer. The exercise data generated by health and fitness devices (eg, treadmill, exercise bike) are very important for health management service providers to develop personalized training programs. However, at present, there is little research on a unified interoperability framework in the health and fitness domain, and there are not many solutions; besides, the privatized treadmill data transmission scheme is not conducive to data integration and analysis.

OBJECTIVE

This article will expand the IEEE 11073-PHD standard protocol family, develop standards for health and fitness device (using treadmill as an example) based on the latest version of the 11073-20601 optimized exchange protocol, and design protocol standards compliance testing process and inspection software, which can automatically detect whether the instantiated object of the treadmill meets the standard.

METHODS

The study includes the following steps: (1) Map the data transmitted by the treadmill to the 11073-PHD objects; (2) Construct a programming language structure corresponding to the 11073-PHD application protocol data unit (APDU) to complete the coding and decoding part of the test software; and (3) Transmit the instantiated simulated treadmill data to the gateway test software through transmission control protocol for standard compliance testing.

RESULTS

According to the characteristics of the treadmill, a data exchange framework conforming to 11073-PHD is constructed, and a corresponding testing framework is developed; a treadmill agent simulation is implemented, and the interoperability test is performed. Through the designed testing process, the corresponding testing software was developed to complete the standard compliance testing of the treadmill.

CONCLUSIONS

The extended research of IEEE 11073-PHD in the field of health and fitness provides a potential new idea for the data transmission framework of sports equipment such as treadmills, which may also provide some help for the development of sports health equipment interoperability standards.

Acute and short-term efficacy of sauna treatment on cardiovascular function: A meta-analysis

OBJECTIVE

The role of sauna bathing in cardiovascular function treatment has been increasingly explored, but insufficient attention has been paid to its efficacy. We performed a meta-analysis to provide more evidence for the efficacy of sauna treatment in cardiovascular nursing.

METHODS

Sixteen peer-reviewed journal articles were screened to summarize the efficacy of the sauna on cardiovascular function. Both acute (0-30 min after the sauna) and short-term (2-4 weeks following the sauna treatment) efficacies were investigated.

RESULTS

For pooled acute efficacy, body temperature and heart rate significantly (p<0.001) grew by 0.94℃ and 17.86 beats/min, respectively; reductions of 5.55 mmHg (p<0.001) and 6.50 mmHg (p<0.001) were also observed in systolic blood pressure and diastole blood pressure, respectively. For combined short-term efficacy, left ventricular ejection fraction (LVEF), 6-min walk distance, and flow-mediated dilation (p<0.001) increased by 3.27%, 48.11 m, and 1.71%, respectively; greater amelioration in LVEF was observed in participants with lower LVEF. The proportion of patients with New York Heart Association class III and IV decreased by 10.9% and 12.2%, respectively. Systolic blood pressure, diastolic blood pressure, brain natriuretic peptide concentration, left ventricular end-diastolic dimension, cardiothoracic ratio, and left atrial dimension reduced by 5.26 mmHg (p<0.001), 4.14 mmHg (p<0.001), 116.66 pg/mL (p<0.001), 2.79 mm (p<0.001), 2.628% (p<0.05), and 1.88 mm (p<0.05), respectively, while the concentration of norepinephrine in the plasma remained unchanged.

CONCLUSION

Sauna treatment was found to play a positive role in improving cardiovascular function and physical activity levels, especially in patients with low cardiovascular function. These findings reveal that thermal intervention may be a promising means for cardiovascular nursing.

Effects of tailored telemonitoring on functional status and health-related quality of life in patients with heart failure

Background

Functional status and health-related quality of life (HRQoL) are important in patients with heart failure (HF). Little is known about the effect of telemonitoring on functional status and HRQoL in that population.

Methods and results

A total of 382 patients with HF (New York Heart Association class 2–4) were included in a randomised controlled trial to investigate the effect of tailored telemonitoring on improving HRQoL and functional status in HF patients. Randomisation was computer-generated with stratification per centre. At baseline and after 12 months, patients’ functional status was determined by metabolic equivalent scores (METS). HRQoL was measured with the EuroQol five dimensions questionnaire (EQ-5D), visual analogue scale (VAS) and Borg rating of perceived exertion scale (Borg). Additional outcome data included number of HF-related outpatient clinic visits and mortality. Telemonitoring was statistically significantly related to an increase in METS after 1 year (regression coefficient 0.318; p = 0.01). Telemonitoring did not improve Borg, EQ-5D or VAS scores after 1 year. EQ-5D [hazard ratio (HR) 0.20, 95% confidence interval (CI) 0.07–0.54], VAS (HR 0.98, 95% CI 0.96–0.99), Borg (HR 1.21, 95% CI 1.11–1.31) and METS (HR 0.73, 95% CI 0.58–0.93) at baseline were significantly associated with survival after 12 months.

Conclusions

Tailored telemonitoring stabilised the functional status of HF patients but did not improve HRQoL. Therefore, telemonitoring may help to prevent deterioration of exercise capacity in patients with HF. However, because our study is a reanalysis of a randomised controlled trial (RCT), this is considered hypothesis-generating and should be confirmed by adequately powered RCTs.

Electronic supplementary material

The online version of this article (10.1007/s12471-019-01323-x) contains supplementary material, which is available to authorized users.

Accuracy of wearable heart rate monitors in cardiac rehabilitation

Background

To assess the accuracy of four wearable heart rate (HR) monitors in patients with established cardiovascular disease enrolled in phase II or III cardiac rehabilitation (CR).

Methods

Eighty adult patients enrolled in phase II or III CR were monitored during a CR session that included exercise on a treadmill and/or stationary cycle. Participants underwent HR monitoring with standard ECG limb leads, an electrocardiographic (ECG) chest strap monitor (Polar H7), and two randomly assigned wrist-worn HR monitors (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, TomTom Spark Cardio), one on each wrist. HR was recorded at rest and at 3, 5, and 7 minutes of steady-state exercise on the treadmill and stationary cycle.

Results

Across all exercise conditions, the chest strap monitor (Polar H7) had the best agreement with ECG (r_c=0.99) followed by the Apple Watch (r_c=0.80), Fitbit Blaze (r_c=0.78), TomTom Spark (r_c=0.76) and Garmin Forerunner (r_c=0.52). There was variability in accuracy under different exercise conditions. On the treadmill, only the Fitbit Blaze performed well (r_c=0.76), while on the stationary cycle, Apple Watch (r_c=0.89) and TomTom Spark (r_c=0.85) were most accurate.

Conclusions

In cardiac patients, the accuracy of wearable, optically based HR monitors varies, and none of those tested was as accurate as an electrode-containing chest monitor. This observation has implications for in-home CR, as electrode-containing chest monitors should be used when accurate HR measurement is imperative.

Application of a Web-Enabled Leg Training System for the Objective Monitoring and Quantitative Analysis of Exercise-Induced Fatigue

Background

Sustained cardiac rehabilitation is the key intervention in the prevention and treatment of many human diseases. However, implementation of exercise programs can be challenging because of early fatigability in patients with chronic diseases, overweight individuals, and aged people. Current methods of fatigability assessment are based on subjective self-reporting such as rating of perceived exertion or require specialized laboratory conditions and sophisticated equipment. A practical approach allowing objective measurement of exercise-induced fatigue would be useful for the optimization of sustained delivery of cardiac rehabilitation to improve patient outcomes.

Objectives

The objective of this study is to develop and validate an innovative approach, allowing for the objective assessment of exercise-induced fatigue using the Web-enabled leg rehabilitation system.

Methods

MedExercise training devices were equipped with wireless temperature sensors in order to monitor their usage by temperature rise in the resistance unit (Δt°). Since Δt° correlated with the intensity and duration of exercise, this parameter was used to characterize participants’ leg work output (LWO). Personal smart devices such as laptop computers with wireless gateways and relevant software were used for monitoring of self-control training. Connection of smart devices to the Internet and cloud-based software allowed remote monitoring of LWO in participants training at home. Heart rates (HRs) were measured by fingertip pulse oximeters simultaneously with Δt° in 7 healthy volunteers.

Results

Exercise-induced fatigue manifested as the decline of LWO and/or rising HR, which could be observed in real-time. Conversely, training at the steady-state LWO and HR for the entire duration of exercise bout was considered as fatigue-free. The amounts of recommended daily physical activity were expressed as the individual Δt° values reached during 30-minute fatigue-free exercise of moderate intensity resulting in a mean of 8.1°C (SD 1.5°C, N=7). These Δt° values were applied as the thresholds for sending automatic notifications upon taking the personalized LWO doses by self-control training at home. While the mean time of taking LWO doses was 30.3 (SD 4.1) minutes (n=25), analysis of times required to reach the same Δt° by the same participant revealed that longer durations were due to fatigability, manifesting as reduced LWO at the later stages of training bouts. Typically, exercising in the afternoons associated with no fatigue, although longer durations of evening sessions suggested a diurnal fatigability pattern.

Conclusions

This pilot study demonstrated the feasibility of objective monitoring of fatigue development in real-time and online as well as retrospective fatigability quantification by the duration of training bouts to reach the same exercise dose. This simple method of leg training at home accompanied by routine fatigue monitoring might be useful for the optimization of exercise interventions in primary care and special populations.