ECG Measurements Research Articles

Influence of heart rate correction formulas on QTc interval stability

Monitoring of QTc interval is mandated in different clinical conditions. Nevertheless, intra-subject variability of QTc intervals reduces the clinical utility of QTc monitoring strategies. Since this variability is partly related to QT heart rate correction, 10 different heart rate corrections (Bazett, Fridericia, Dmitrienko, Framingham, Schlamowitz, Hodges, Ashman, Rautaharju, Sarma, and Rabkin) were applied to 452,440 ECG measurements made in 539 healthy volunteers (259 females, mean age 33.3 ± 8.4 years). For each correction formula, the short term (5-min time-points) and long-term (day-time hours) variability of rate corrected QT values (QTc) was investigated together with the comparisons of the QTc values with individually corrected QTcI values obtained by subject-specific modelling of the QT/RR relationship and hysteresis. The results showed that (a) both in terms of short-term and long-term QTc variability, Bazett correction led to QTc values that were more variable than the results of other corrections (p < 0.00001 for all), (b) the QTc variability by Fridericia and Framingham corrections were not systematically different from each other but were lower than the results of other corrections (p-value between 0.033 and < 0.00001), and (c) on average, Bazett QTc values departed from QTcI intervals more than the QTc values of other corrections. The study concludes that (a) previous suggestions that Bazett correction should no longer be used in clinical practice are fully justified, (b) replacing Bazett correction with Fridericia and/or Framingham corrections would improve clinical QTc monitoring, (c) heart rate stability is needed for valid QTc assessment, and (d) development of further QTc corrections for day-to-day use is not warranted.

Minimizing Myocardial Ischemic Injury by Cool Dialysate in Maintenance Hemodialysis Patients: A Randomized Controlled Trial

Background: Emerging evidence supports a cardiovascular protective role of Cooled Dialysis (CD) in incident Hemodialysis (HD) patients. Whether this benefit can be extended to maintenance HD patients remains to be established. Objective: The aim of the present study was to assess the impact of CD by lowering Dialysate temperature (dt) 0.5oC below Core Body Temperature (CBT), on minimizing myocardial ischemia in maintenance HD patients (>1 year on HD). Patients and Methods: from March 2019 to January 2021, we randomized one hundred maintenance HD patients to receive either Cooled Dialysis (dt - 0.5oC below CBT, intervention) or Standard Dialysis (dt= CBT, control) for 12 months. Over the study period, serial measurements of ECG, echocardiography, and myocardial enzymes (CK-MB and Troponin-T) were performed for the whole study population as surrogates for myocardial ischemic injury. Results: By the end of 12-months, compared to Standard Dialysis (ST) patients, Cooled Dialysis (CD) patients had overall less incidence of new myocardial ischemia (composite surrogate outcomes: ECG, Echo and CK-MB) (p=0.032). In logistic regression analysis, CD was found to be independently protective against myocardial ischemia (OR 0.54, p-value 0.033, CI: 0.3-0.95). Conclusion: In maintenance HD patients, Cooled Dialysis might help decrease myocardial ischemia with a reasonable safety profile. Further studies are warranted to explore these findings.

VLSI Based Architecture in ECG Monitoring for Adaptive Power Management In Wireless Bio Signal Acquisition Network

For the diagnosis and elimination of cardiovascular diseases, the ECG system has evolved as smarter healthcare professionals. As almost all of these networks are battery-operated, the whole device’s total life is greatly shortened by self-centred communication connections. This paper will present a power control technique and the accompanying VLSI design to improve the Asic ECG heart monitor’s lifespan powered by the battery. The suggested power control strategy dynamically adjusts between two transmission modes, i.e. high performance / lower energy modes, available for a device’s energy level. Because localized storage is energy, for true monitoring of QRS complexity and breathing rates assessment, a streamlined methodology focusing on slopes improvement with runtime adaptive thresholding is intended to guarantee maximum energy usage throughout limited energy level. The required communication mode is chosen based mostly on batteries and pulse rate consistency, which essentially fulfils the Wireless Body Sensor Communication network objective. Collecting appropriate ECG collections from a single customer and enhancing the longevity of the device. Response and efficiency are evaluated for the proposed method The ultra - low - power signal generator with a relaxing scope range of 1-3 m will be built to retain a bigger battery. Any transmitter and receiver for remote private communication standards have been established lately. It is not the best option for ultra-low power WBAN implementations. The Spartan 6 FPGA design has been introduced with a peak clock frequency of 269 MHz with an energy demand of 0.3mW, specially designed for actual ECG measurement techniques.

Suitability Assessment of the Functional Content Platform for Stress Reduction in Firefighters

Firefighters are constantly exposed to dangers in disaster sites and they need a plan to safeguard their mental health. There are various programs in place, such as mental and physical health stabilization rooms, to reduce stress and prevent mental illnesses. While these are easily accessible during work, they are lacking in function. To effectively decrease the stress of firefighters, a 65-inch TV set, a healing chair, and an aromatic device were installed in an independent booth, called a healing room. Such rooms were built in fire stations and its effects on stress were analyzed. Five quantitative indicators were identified based on the ECG measurement of firefighters and stress reduction effects were confirmed. Additionally, for the qualitative analysis, mental health interviews of firefighters confirmed stress reduction. The results of this study are expected to be used as baseline data to enhance psychological resilience in firefighters and to revitalize their mental and physical health using stabilization rooms.

Noise-Reducing Fabric Electrode for ECG Measurement.

In this work, we propose a fabric electrode with a special structure that can play the role of a noise reduction filter. Fabric electrodes made of the conductive fabric have been used for long-term ECG measurements because of their flexibility and non-invasiveness; however, due to the large impedance between the skin and the fabric electrodes, noise is easily introduced into the ECG signal. In contrast to conventional work, in which chip-type passive elements are glued to the electrode to reduce noise, the proposed electrode can obtain a noise-reduced ECG by changing the structure of fabric. Specifically, the proposed electrode was folded multiple times to form a capacitor with a capacitance of about 3 nF. It is combined with the skin-electrode impedance to form a low-pass filter. In the experiment, we made a prototype of the electrodes and measured ECG at rest and during EMG-induced exercise. As a result, the SNR values at rest and during exercise were improved about 12.02 and dB, respectively, compared with the fabric electrode without special structure. In conclusion, we have shown that changing the fabric electrode structure effectively removes noise in ECG measurement.

Capsimax Increases Resting Energy Expenditure in Males Under Fasting State: A Randomized, Double-Blind, Placebo Controlled, Cross-Over Study

Abstract Objectives Obesity is caused by an imbalance between energy intake and energy expenditure. Resting energy expenditure (REE) represents the calories burned at rest and accounts for &amp;gt; 60% of total energy expenditure. Energy expenditure plays an important role in obesity development, hence an increase in REE could facilitate body weight reduction. Capsaicinoids, extracted from capsicum annuum have been known to increase metabolism, lipolysis &amp; induce satiety. The study objective was to evaluate the effects of Capsimax™ on REE and thermal sensation. Methods This was a randomized, double-blind, placebo controlled, cross-over study. Efficacy analysis included subsets of 17 males and 7 females who received single dose of Capsimax™ 100 mg (2 mg total capsaicinoids) and placebo in a cross-over fashion with washout period of 3–6 days as per randomization schedule. REE was measured using Cosmed Q-NRG by indirect calorimetry. Secondary objectives were Area under curve (AUC) for REE, VO2, VCO2 &amp; subject's innate thermal sensation using American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) scale. REE, VO2, VCO2, ASHRAE scale were evaluated at 0 (pre-dose), 1, 2, 3 &amp; 4 hours and additional measures for ASHRAE scale at 0.5 &amp; 1.5 hours post-dose. Safety was assessed throughout the study with measurements of ECG, blood pressure, pulse rate, body temperature &amp; adverse event occurrences. Results In males, CapsimaxTM consumption significantly increased (p &amp;lt; 0.05) the change in REE at 1 hr (+90.19 ± 36.99 kcal Vs -92.97 ± 35.95 kcal), 2 hr (+77.17 ± 35.12 kcal Vs -41.90 ± 35.12 kcal), 3 hr (+48.47 ± 38.60 kcal Vs −51.74 ± 37.69 kcal) &amp; 4 hr (+30.17 ± 40.37 kcal Vs −43.88 ± 40.37 kcal) as compared to placebo. Significant differences (p &amp;lt; 0.05) were also seen for AUC0–2 REE, VO2 at 1, 2 &amp; 3 hrs and VCO2 at 3 hrs for CapsimaxTM versus placebo. Although not significantly different, subject's in CapsimaxTM group showed higher feelings of warmth at all time points post dose based on ASHRAE score versus placebo. No significant differences were observed for any of the endpoints in females. No safety issues or adverse events were seen. Conclusions Our study findings demonstrate that CapsimaxTM supplementation increases REE in males and may represent a useful nutritional strategy to help weight management efforts. Funding Sources OmniActive Health Technologies Ltd.

Kardia Mobile and ISTEL HR applicability in clinical practice: a comparison of Kardia Mobile, ISTEL HR, and standard 12-lead electrocardiogram records in 98 consecutive patients of a tertiary cardiovascular care centre.

Mobile, portable ECG-recorders allow the assessment of heart rhythm in out-of-hospital conditions and may prove useful for monitoring patients with cardiovascular diseases. However, the effectiveness of these portable devices has not been tested in everyday practice. A group of 98 consecutive cardiology patients [62 males (63%), mean age 69 ± 12.9 years] were included in an academic care centre. For each patient, a standard 12-lead electrocardiogram (SE), as well as a Kardia Mobile 6L (KM) and Istel (IS) HR-2000 ECG were performed. Two groups of experienced physicians analysed obtained recordings. After analysing ECG tracings from SE, KM, and IS, quality was marked as good in 82%, 80%, and 72% of patients, respectively (P < 0.001). There were no significant differences between devices in terms of detecting sinus rhythm [SE (60%, n = 59), KM (58%, n = 56), and IS (61%, n = 60); SE vs. KM P = 0.53; SE vs. IS P = 0.76) and atrial fibrillation [SE (22%, n = 22), KM (22%, n = 21), and IS (18%, n = 18); (SE vs. KM P = 0.65; SE vs. IS = 0.1)]. KM had a sensitivity of 88.1% and a specificity of 89.7% for diagnosing sinus rhythm. IS showed 91.5% and 84.6% sensitivity and specificity, respectively. The sensitivity of KM in detecting atrial fibrillation was higher than IS (86.4% vs. 77.3%), but their specificity was comparable (97.4% vs. 98.7%). Novel, portable devices are useful in showing sinus rhythm and detecting atrial fibrillation in clinical practice. However, ECG measurements concerning conduction and repolarization should be clarified with a standard 12-lead electrocardiogram.

Feasibility of a Waistband-Type Wireless Wearable Electrocardiogram Monitoring System Based on a Textile Electrode: Development and Usability Study.

BackgroundElectrocardiogram (ECG) monitoring in daily life is essential for effective management of cardiovascular disease, a leading cause of death. Wearable ECG measurement systems in the form of clothing have been proposed to replace Holter monitors used for clinical ECG monitoring; however, they have limitations in daily use because they compress the upper body and, in doing so, cause discomfort during wear.ObjectiveThe purpose of this study was to develop a wireless wearable ECG monitoring system that includes a textile ECG electrode that can be applied to the lining of pants and can be used in the same way that existing lower clothing is worn, without compression to the upper body.MethodsA textile electrode with stretchable characteristics was fabricated by knitting a conductive yarn together with polyester-polyurethane fiber, which was then coated with silver compound; an ECG electrode was developed by placing it on an elastic band in a modified limb lead configuration. In addition, a system with analog-to-digital conversion, wireless communication, and a smartphone app was developed, allowing users to be able to check and store their own ECGs in real time. A signal processing algorithm was also developed to remove noise from the obtained signal and to calculate the heart rate. To evaluate the ECG and heart rate measurement performance of the developed module, a comparative evaluation with a commercial device was performed. ECGs were measured for 5 minutes each in standing, sitting, and lying positions; the mean absolute percentage errors of heart rates measured with both systems were then compared.ResultsThe system was developed in the form of a belt buckle with a size of 53 × 45 × 12 mm (width × height × depth) and a weight of 23 g. In a qualitative evaluation, it was confirmed that the P-QRS-T waveform was clearly observed in ECGs obtained with the wearable system. From the results of the heart rate estimation, the developed system could track changes in heart rate as calculated by a commercial ECG measuring device; in addition, the mean absolute percentage errors of heart rates were 1.80%, 2.84%, and 2.48% in the standing, sitting, and lying positions, respectively.ConclusionsThe developed system was able to effectively measure ECG and calculate heart rate simply through being worn as existing clothing without upper body pressure. It is anticipated that general usability can be secured through further evaluation under more diverse conditions.

Analysis on Electrocardiogram Measurement Performance Using Metal Electrode Based on 1-D Convolutional Neural Network for Application of Wearable Device

Disposable electrode is mainly used when measuring ECG signals. However, disposable electrode has low re-usability and durability, making it difficult to obtain high-quality signals when used for a long term. In this paper, we evaluated the applicability of metal plates and conductive tapes as new reference electrode to replace disposable electrode. For evaluation, we implemented a 1D CNN-based training model and an ECG measurement system to collect data. The implemented neural network was trained based on the MIT-BIH arrhythmia data set, and 5 classes of ECG classification including normal signals are possible. For measurement evaluation of metal plates, conductive tapes, and disposable electrode, field tests were conducted using the trained model. The ECG class classification of the implemented CNN training model confirmed a classification accuracy of more than 96%, and compared with previously studied pattern matching algorithms and other studies, confirmed excellent detection performance. In the field test, performance evaluation of arrhythmia classification was performed using a neural network trained on ECG signals obtained with disposable electrode, metal plates, and conductive tape. The ECG signals for evaluation used in the experiment, 300 samples were measured for each class from 10 subjects. As a result of the experiment, it was confirmed that the disposable electrode was classified as 98.59%, the metal plate was classified as 95.26%, and the conductive tape was classified as 96.13%. It is inconvenient to measure ECG using disposable electrode in everyday life. However, there is no difference in ECG detection performance in the case of a metal plate and a conductive tape compared to a disposable electrode. In addition, metal plates and conductive tapes can be easily applied to existing wearables because they can be reused and long term.

Electronic frailty index for predicting mortality outcome of patients undergoing transaortic valvular implantation

Abstract Funding Acknowledgements Type of funding sources: None. Objective Electronic frailty index for predicting mortality outcome of patients undergoing transaortic valvular implantation (TAVI) served as useful surrogates but is associated with a poor prognosis since it needs long time to determine the frailty status and develop the index based on electronic health records. We identify significant risk mortality predictors and tested the hypothesis that an electronic frailty index incorporating ECG measurements and laboratory examinations using a machine learning survival analysis approach can improve TAVI mortality prediction. Design A territory-wide observational study which involved a total of 450 patients (49.11% females, 22 mortalities) diagnosed undergoing TAVI and admitted to public hospitals from Hong Kong. Methods Demographics (TAVI presentation age, gender, severity of TR, AR, MR, PR, INR of TAVI presentation), prior comorbidities before TAVI presentation, ECG measurements, and CBC and LRFT laboratory examinations were analyzed. Cox regression and a supervised sequential ensemble learning algorithm: gradient boosting survival tree (GBST) model, was applied to predict mortality. Significant univariate and multivariate risk predictors of mortality were identified. Importance ranking of variables were obtained with GBST model and used to build the frailty models. Comparisons were provided with baseline models of random survival forests and multivariate Cox regression. Results The median TAVI presentation age was 82.3 years (83.8 years in mortalities, and 82.1 years in alive patients). INR of TAVI presentation in mortalities (median: 1.32) is much higher than alive ones (median: 1.07). Severe TR (hazard ratio, HR: 8.93, 95% CI: [3.22, 24.78], p value &amp;lt; 0.0001), INR of TAVI presentation (HR: 2.74, 95% CI: [1.84, 4.09], p value &amp;lt; 0.0001), cumulative hospital stays (HR: 1.01, 95% CI: [1.00, 1.01], p value = 0.0008), aspartate transaminase (HR: 1.01, 95% CI: [0.98, 1.002], p value = 0.0002), and bilirubin (HR: 1.02, 95% CI: [1.01, 1.02], p value = 0.0003) are significant mortality risk predictors. Machine learning survival analysis model found that APTT demonstrates the most important strength, followed by INR of TAVI presentation, severe TR status, cumulative hospital stays, cumulative readmission times, creatinine test, urate test ALP test, and ECG measurements of QTc and QT. GBST significantly outperformed random survival forests and multivariate Cox regression (precision: 0.91, recall: 0.89, AUC: 0.93, C-index: 0.96, and KS-index: 0.50) for mortality prediction. Conclusions Electronic frailty index based on demographics, prior comorbidities, hospitalization characteristics, ECG measurements, and laboratory examinations can efficiently predict mortality outcome of patients undergoing TAVI. Machine learning survival learning model significantly improves the risk prediction performance and improves the construction of the frailty models for tailored interventions of TAVI patients in clinical practices.

Rescue Operations Lead to Increased Cardiovascular Stress in HEMS Crew Members: A Prospective Pilot Study of a German HEMS Cohort

Helicopter emergency medical service (HEMS) is an essential part of prehospital emergency medicine. The working conditions lead to high physical stress, especially in rescue operations. The study aimed to determine the cardiovascular stress profile during rescue situations in HEMS crew members. Twenty-one HEMS crew members (male n = 20) participated in the prospective study. Heart rate, blood pressure and long-term ECG measurements were recorded during the whole operation day. The changes of measurements during rescue operation (52 operations in total) were compared to these of standby time. Rescue operations lead to increased load on the cardiovascular system, as expressed by significantly higher blood pressure, heart rate values and rate of cardiac events compared to standby time. Of special note, the difference in systolic blood pressure mean was 7.4 ± 9.0 mmHg (CI [5.1; 9.7], p < 0.001). Maximal heart rate was on average 33.7 bpm higher during rescue operation than in the standby time (CI [26.2; 40.8], p < 0.001). Cardiac events occurred significantly more frequently during the period of rescue operation than in standby time hours (p = 0.02). The results reported a significant load on the cardiovascular system during rescue operations in HEMS crew members. Therefore, it is necessary to carry out a risk stratification of the HEMS crew members to prevent cardiovascular risk and events.

Development of ECG measurement and processing system in LabVIEW environment

Abstract In this project an ECG measurement and wave identification system was made. The measuring system hardware is based on a Texas Instruments ADS1298ECG amplifier and analog-to-digital converter board. The measurement and processing software was created in LabVIEW environment using the built-in functions of the Biomedical toolkit. Initially, the theory behind heartbeat and its effect on the skin surface potential are presented. Then the measurement techniques of these are described. The research group provide information on the mathematical background of how the ECG curve is processed and the waves are identified. The HRV analysis, the statistical analysis of identified R waves are described. Subsequently, publications dealing with electrocardiographic examinations in various fields will be presented. Then an overview of the specifications of the amplifiers used in this work and the capabilities of their original software are given. The final device structure is presented. The system validation process and the properties of the reference devices are illustrated.

Supplementation of Lipoic Acid, Zinc and Clopidogrel Reduces Mortality Rate and Incidence of Ventricular Arrhythmia in Experimental Myocardial Infarction.

Despite the significant advances in management of coronary heart diseases, myocardial infarction (MI) is still associated with a high mortality rate. The present study was planned to investigate the possible protective effects of the anti-oxidants lipoic acid and zinc sulfate as well as the anti-platelet clopidogrel on cardiac dysfunction in experimental isoproterenol (ISO)-induced MI, aiming at achieving useful means for protection and therapy against MI. Wistar rats of both sexes were allocated into five groups: control, untreated MI and MI pre-treated with lipoic acid, zinc, or clopidogrel. All rats were subjected to ECG recording and measurement of plasma levels of troponin I, creatine kinase-MB (CK-MB) unit, triglycerides and total cholesterol. The hearts were isolated and studied on Langendorff preparation for assessment of intrinsic cardiac activities. The results revealed that the percent mortality was markedly reduced upon pre-treatment and the total arrhythmia was also decreased except for the zinc pre-treated rats. The ST-segment elevation was significantly reduced and the plasma levels of CK-MB were only decreased in lipoic acid and clopidogrel pre-treated rats with variable hypolipidemic effect. Hearts of clopidogrel pre-treated rats showed augmented inotropic activity both basal and in response to β-adrenergic stimulation. While zinc pre-treated hearts revealed improved rate of contraction and increased myocardial flow rate. Overall, these results indicate that lipoic acid, zinc and clopidogrel were variably effective in modifying the ISO-induced MI insults and offered partial protection against experimental myocardial damage.

A High-Precision Machine Learning Algorithm to Classify Left and Right Outflow Tract Ventricular Tachycardia

IntroductionMultiple algorithms based on 12-lead ECG measurements have been proposed to identify the right ventricular outflow tract (RVOT) and left ventricular outflow tract (LVOT) locations from which ventricular tachycardia (VT) and frequent premature ventricular complex (PVC) originate. However, a clinical-grade machine learning algorithm that automatically analyzes characteristics of 12-lead ECGs and predicts RVOT or LVOT origins of VT and PVC is not currently available. The effective ablation sites of RVOT and LVOT, confirmed by a successful ablation procedure, provide evidence to create RVOT and LVOT labels for the machine learning model.MethodsWe randomly sampled training, validation, and testing data sets from 420 patients who underwent successful catheter ablation (CA) to treat VT or PVC, containing 340 (81%), 38 (9%), and 42 (10%) patients, respectively. We iteratively trained a machine learning algorithm supplied with 1,600,800 features extracted via our proprietary algorithm from 12-lead ECGs of the patients in the training cohort. The area under the curve (AUC) of the receiver operating characteristic curve was calculated from the internal validation data set to choose an optimal discretization cutoff threshold.ResultsThe proposed approach attained the following performance: accuracy (ACC) of 97.62 (87.44–99.99), weighted F1-score of 98.46 (90–100), AUC of 98.99 (96.89–100), sensitivity (SE) of 96.97 (82.54–99.89), and specificity (SP) of 100 (62.97–100).ConclusionsThe proposed multistage diagnostic scheme attained clinical-grade precision of prediction for LVOT and RVOT locations of VT origin with fewer applicability restrictions than prior studies.

ПРОГНОЗУВАННЯ РИЗИКУ ВИНИКНЕННЯ СЕРЦЕВО-СУДИННИХ УСКЛАДНЕНЬ НА ОСНОВІ КЛАСТЕРНОГО АНАЛІЗУ ТРИВАЛОСТІ ІНТЕРВАЛУ QT ПРИ ЦУКРОВОМУ ДІАБЕТІ 1 ТИПУ У ДІТЕЙ

Clinical and scientific experience of curation and analysis of children with type 1 diabetes and with acquired or congenital long QT syndrome (LQTS) health is not enough discovered for full control, treatment and risks prediction. Іn this work we investigated interconnection of type 1 diabetes in children and possibility of cardiovascular disorders taking into account the results of twenty-four-hour Holter ECG monitoring and measurement of QT and QTc in 3 leads (CM5, CS1, CS3) . To predict the risk of cardiovascular complications in the form of sudden ventricular life-threatening tachyarrhythmias, we made an assessment of risk groups using hierarchical cluster analysis and determined three groups. The low-risk group included children who did not have an increase in the duration of QT and QTc intervals in any of the leads; the high-risk group included children who had an increase in the duration of the QT and QTc intervals and the variance of these intervals in several leads simultaneously. The medium-risk group included children who had prolongation of QT and QTc intervals in only 1 lead or had a change in the variance of these intervals. According to the results of our analysis, the main goal of reducing the risk of life-threatening complications in children with type 1 diabetes is the timely diagnosis of long QT interval syndrome, especially its congenital form, for further management of these patients at simultaneous appointment of insulin therapy and correction of episodes of hypoglycemia, which can impair a course of a syndrome of the prolonged QT interval.

Cannabis is associated with blood pressure reduction in older adults – A 24-hours ambulatory blood pressure monitoring study

Background: Medical cannabis use is increasing rapidly in the past several years, with older adults being the fastest growing group. Nevertheless, the evidence for cardiovascular safety of cannabis use is scarce. The aim of this study was to assess the effect of cannabis on blood pressure, heart rate, and metabolic parameters in older adults with hypertension.Methods: We conducted a prospective study of patients aged 60 years or more with hypertension and a new prescription of cannabis. We have performed the following assessments: 24-hours ambulatory blood pressure monitoring, ECG, blood tests, and anthropometric measurements prior to the initiation of cannabis therapy and 3 months afterward. The primary outcome was change in mean 24-h blood pressure at 3 months.Results: Twenty-six patients with a mean age of 70.42 ± 5.37 years, 53.8% females completed the study. At 3 months follow-up, the mean 24-hours systolic and diastolic blood pressures were reduced by 5.0 mmHg and 4.5 mmHg, respectively (p<0.001 for both). The nadir for the blood pressure and heart rate was achieved at 3 hours post-administration. The proportion of normal dippers changed from 27.3% before treatment to 45.5% afterward. No significant changes were seen in the different metabolic parameters assessed by blood tests, anthropometric measurements, or ECG exam.Conclusion: amongst older adults with hypertension, cannabis treatment for 3 months was associated with a reduction in 24-hours systolic and diastolic blood pressure values with a nadir at 3 hours after cannabis administration.

Prognostic impact of electrocardiographic left ventricular hypertrophy following transcatheter aortic valve replacement

BackgroundLeft ventricular hypertrophy (LVH) develops with both structural and electrical remodeling in response to elevated afterload due to aortic stenosis (AS). This study evaluated the prognostic value of electrocardiographic LVH (ECG LVH) after transcatheter aortic valve replacement (TAVR). MethodsA retrospective study including 157 consecutive patients who underwent TAVR was conducted. ECG LVH was defined as Sokolow–Lyon voltage (S in V1 + R in V5/6) before TAVR was ≥3.5mV. We investigated the association between ECG LVH and the 1-year composite outcome comprising all-cause death and rehospitalization related to heart failure. ECG and echocardiographic measurements at 1, 6, and 12 months after TAVR were assessed. ResultsThe baseline characteristics were comparable between the ECG LVH (n = 74) and non-ECG LVH groups (n = 83). The ECG LVH was associated with a significantly greater reduction of Sokolow–Lyon voltage and LV mass index than the non-ECG LVH after TAVR. The absence of ECG LVH was an independent predictor of the 1-year composite outcome [adjusted hazard ratio (HR), 2.27; 95% confidence interval (CI), 1.01 – 5.60; p = 0.04]. Furthermore, a reduction of Sokolow–Lyon voltage from baseline to 1-month follow-up, but not a reduction of LV mass index, was associated with a lower cumulative composite outcome from 1 month to 1 year (adjusted HR, 0.36; 95% CI, 0.15 – 0.86; p = 0.02). ConclusionsECG LVH was associated with a low incidence of adverse clinical outcomes and greater reverse LV remodeling after TAVR. Preprocedural and serial LVH assessment by ECG might be useful in AS patients undergoing TAVR.

Long-Term Safety and Feasibility of Left Bundle Branch Pacing in a Large Single-Center Study.

Left bundle branch pacing (LBBP) is a novel pacing method and has been observed to have low and stable pacing thresholds in prior small short-term studies. The objective of this study was to evaluate the feasibility and safety of LBBP in a large consecutive diverse group of patients with long-term follow-up. This study prospectively enrolled 632 consecutive pacemaker patients with attempted LBBP from April 2017 to July 2019. Pacing parameters, complications, ECG, and echocardiographic measurements were assessed at implant and during follow-up of 1, 6, 12, and 24 months. LBBP was successful in 618/632 (97.8%) patients according to strict criteria for LBB capture. Mean follow-up time was 18.6±6.7 months. Two hundred thirty-one patients had follow-up over 2 years. LBB capture threshold at implant was 0.65±0.27 mV at 0.5 ms and 0.69±0.24 mV at 0.5 ms at 2-year follow-up. A significant decrease in QRS duration was observed in patients with left bundle branch block (167.22±18.99 versus 124.02±24.15 ms, P<0.001). Postimplantation left ventricular ejection fraction improved in patients with QRS≥120 ms (48.82±17.78% versus 58.12±13.04%, P<0.001). The number of patients with moderate and severe tricuspid regurgitation decreased at 1 year. Permanent right bundle branch injury occurred in 55 (8.9%) patients. LBB capture threshold increased to >3 V or loss of bundle capture in 6 patients (1%), 2 patients of them had a loss of conduction system capture. Two patients required lead revision due to dislodgement. This large observational study suggests that LBBP is feasible with high success rates and low complication rates during long-term follow-up. Therefore, LBBP appears to be a reliable method for physiological pacing for patients with either a bradycardia or heart failure pacing indication.

Capacitively Coupled Electrode Array Sensors for Body Posture and ECG Measurement During Sleep

Holter electrocardiographs, which are commonly used for long-term electrocardiographic measurements, are not necessarily suitable for long-term measurements during sleep because the electrodes are directly attached to the skin, causing discomfort and constraint feelings. To handle this problem, electrocardiogram measurement using capacitively coupled electrodes, which do not require direct skin contact, could be an alternative. However, this method requires precise positioning of the electrodes on specific parts of the body, which makes it difficult to work robustly in response to physical body differences and postural variations such as turning over. Therefore, the authors have been working on the realization of a novel electrocardiogram measurement system using capacitively coupled electrodes arranged in an array. The major feature of this system is the ability to measure both body posture and electrocardiogram with common electrodes arranged in an array, and by selecting the most effective electrodes based on the measured posture, it can make electrocardiogram measurements corresponding to the posture changes. In this paper, as the core of the system, a new sensor that can measure both body posture and electrocardiogram with common arrayed electrodes has been designed and implemented. From the experimental results, it was confirmed that the subject's posture on the electrode array could be obtained from the distribution of capacitance, and also the electrocardiogram of the subject could be obtained with the same electrodes as well.

Vibration Perception Threshold and Heart Rate Variability as methods to assess chemotherapy-induced neuropathy in women with breast cancer – a pilot study

PurposeChemotherapy-induced peripheral neuropathy (CIPN) is a recognized adverse effect of standard (neo)adjuvant chemotherapy in breast cancer (BC) treatment. However, there is no consensus on a validated method for assessing CIPN. Heart rate variability (HRV) and vibration perception threshold (VPT) could be used as objective measures to describe CIPN. The aim of this pilot study was to investigate whether subjectively reported CIPN was associated with altered HRV and VPT in BC patients. MethodsWe performed a cross-sectional pilot study evaluating 30 BCE patients previously treated with chemotherapy, 26 BCE patients who did not receive chemotherapy, and 22 controls without breast cancer. Self-reported CIPN was registered for the BC patients. All participants were subjected to multi-frequency vibration analyses to determine VPT along with short ECG measurements to determine HRV measures. ResultsSelf-reported CIPN was registered in 14 (46.6%) BC patients treated with chemotherapy. The VPT at 64 Hz (P = 0.022) and mean HR (P = 0.022) were significantly higher and the HRV measures SDNN (P = 0.023), RMSSD (P = 0.007), LF (P = 0.050) and HF (P = 0.045) were significantly lower in BC patients reporting CIPN compared to controls when adjusted for age. VPT at 64 Hz and 125 Hz were significantly higher in BC patients not reporting CIPN compared to controls when adjusted for age. ConclusionWe found elevated VPT and mean HR along with decreased HRV parameters in 14 BCE patients reporting CIPN. These findings support the need for further investigation into whether HRV and vibration analysis could contribute to an objective assessment of CIPN.