The clinical significance of continuous ECG (ambulatory ECG or Holter) monitoring of the ST-segment to evaluate ischemia: a review

S4D-ECG: A Shallow State-of-the-Art Model for Cardiac Abnormality Classification

PURPOSE

This study introduces an algorithm specifically designed for processing unprocessed 12-lead electrocardiogram (ECG) data, with the primary aim of detecting cardiac abnormalities.

METHODS

The proposed model integrates Diagonal State Space Sequence (S4D) model into its architecture, leveraging its effectiveness in capturing dynamics within time-series data. The S4D model is designed with stacked S4D layers for processing raw input data and a simplified decoder using a dense layer for predicting abnormality types. Experimental optimization determines the optimal number of S4D layers, striking a balance between computational efficiency and predictive performance. This comprehensive approach ensures the model's suitability for real-time processing on hardware devices with limited capabilities, offering a streamlined yet effective solution for heart monitoring.

RESULTS

Among the notable features of this algorithm is its strong resilience to noise, enabling the algorithm to achieve an average F1-score of 81.2% and an AUROC of 95.5% in generalization. The model underwent testing specifically on the lead II ECG signal, exhibiting consistent performance with an F1-score of 79.5% and an AUROC of 95.7%.

CONCLUSION

It is characterized by the elimination of pre-processing features and the availability of a low-complexity architecture that makes it suitable for implementation on numerous computing devices because it is easily implementable. Consequently, this algorithm exhibits considerable potential for practical applications in analyzing real-world ECG data. This model can be placed on the cloud for diagnosis. The model was also tested on lead II of the ECG alone and has demonstrated promising results, supporting its potential for on-device application.

Revisiting the diagnostic and prognostic significance of high-frequency QRS analysis in cardiovascular diseases: a comprehensive review

Cardiovascular diseases (CVDs) present a significant global public health threat, contributing to a substantial number of cases involving morbidity and mortality. Therefore, the early and accurate detection of CVDs plays an indispensable role in enhancing patient outcomes. Decades of extensive research on electrocardiography at high frequencies have yielded a wealth of knowledge regarding alterations in the QRS complex during myocardial ischemia, as well as the methodologies to assess and quantify these changes. In recent years, the analysis of high-frequency QRS (HF-QRS) components has emerged as a promising non-invasive approach for diagnosing various cardiovascular conditions. Alterations in HF-QRS amplitude and morphology have demonstrated remarkable sensitivity as diagnostic indicators for myocardial ischemia, often surpassing measures of ST-T segment changes. This comprehensive review aims to provide an intricate overview of the current advancements, challenges, and prospects associated with HF-QRS analysis in the field of CVDs.

Heart Rate Measurement Using the Built-In Triaxial Accelerometer from a Commercial Digital Writing Device

Currently, wearable technology is an emerging trend that offers remarkable access to our data through smart devices like smartphones, watches, fitness trackers and textiles. As such, wearable devices can enable health monitoring without disrupting our daily routines. In clinical settings, electrocardiograms (ECGs) and photoplethysmographies (PPGs) are used to monitor heart and respiratory behaviors. In more practical settings, accelerometers can be used to estimate the heart rate when they are attached to the chest. They can also help filter out some noise in ECG signals from movement. In this work, we compare the heart rate data extracted from the built-in accelerometer of a commercial smart pen equipped with sensors (STABILO's DigiPen) to standard ECG monitor readouts. We demonstrate that it is possible to accurately predict the heart rate from the smart pencil. The data collection is carried out with eight volunteers writing the alphabet continuously for five minutes. The signal is processed with a Butterworth filter to cut off noise. We achieve a mean-squared error (MSE) better than 6.685 × 10-3 comparing the DigiPen's computed Δt (time between pulses) with the reference ECG data. The peaks' timestamps for both signals all maintain a correlation higher than 0.99. All computed heart rates (HR =60Δt) from the pen accurately correlate with the reference ECG signals.

Antihypertensive activity of different components of Veratrum alkaloids through metabonomic data analysis

BACKGROUND

Hypertension is a serious global public health issue. Blood pressure (BP) is still not effectively controlled in about 20 - 30% of hypertensive patients. Therefore, it is imperative to develop new treatments for hypertension. Veratrum alkaloids were once used for the clinical treatment of hypertension, the mechanism of which is still unclear. It was gradually phased out due to adverse reactions.

PURPOSE

This study aimed to investigate the short-term and long-term hypotensive profiles of different components of Veratrum alkaloids in spontaneously hypertensive rats (SHRs) to unveil their mechanisms of action.

RESULTS

Total Veratrum alkaloid (V), component A (A), and veratramine (M) quickly decreased BP within 30 min of treatment, reduced renal and cardiovascular damage, and improved relevant biochemical indicators (nitric oxide [NO], endothelin-1 [ET-1], angiotensin II [Ang II)], noradrenaline [NE], etc) in SHRs to delay stroke occurrence. Thereinto, A exhibited excellent protective effects in cardiovascular disease. The metabolomic profiles of SHRs treated with V, A, and M were significantly different from those of SHRs treated with vehicle. Thirteen metabolites were identified as potential pharmacodynamic biomarkers. Through Kyoto Encyclopedia of Genes and Genomes analysis, V, A, and M-induced hypotension was mainly related to alterations in nicotinate and nicotinamide metabolism, GABAergic synapses, linoleic acid metabolism, ketone body synthesis and degradation, arginine and proline metabolism, and urea cycle, of which nicotinate and nicotinamide metabolism was the key metabolic pathway to relieve hypertension.

CONCLUSION

This work shows that A is an effective and promising antihypertensive agent for hypertension treatment to reduce BP and hypertensive target organ damage, which is mainly mediated through modulating nicotinate and nicotinamide metabolism, RAS, and NO-ET homeostasis.

Effectiveness of artificial intelligent cardiac remote monitoring system for evaluating asymptomatic myocardial ischemia in patients with coronary heart disease

OBJECTIVE

To explore the effectiveness of cardiac remote monitoring system (CRMS) based on artificial intelligence-enabled ECG algorithm mode for evaluating asymptomatic myocardial ischemia (AMI) in patients with coronary artery disease (CAD).

METHODS

Two hundred CAD patients confirmed by coronary angiography (CA) in our hospital were included as the study subjects, 120 of whom developed myocardial ischemia (MI). All patients received 12-lead telephone remote ECG monitoring and evaluation. After monitoring, artificial intelligence-enabled ECG algorithm was performed to observe the detection rate of MI.

RESULTS

Compared with artificial intelligence-enabled ECG algorithm combined with remote ECG monitoring system, the detection rate of remote ECG monitoring system in 120 MI patients was lower (96.67% vs. 86.67%, P<0.01). Among the 120 MI patients, there were 26 patients (21.67%) with symptomatic myocardial ischemia (SMI) and 94 patients (78.33%) with AMI. There was no difference between the two detection methods in the diagnosis of SMI (P>0.05), while there was a difference in the diagnosis of AMI (P<0.01). The degree and duration of ST segment decline and the threshold variability of MI were higher in SMI patients than those in AMI patients (P<0.001). It showed that the lowest frequency of MI was from 0:00 to 06:00, and the highest from 06:01 to 12:00, with significant difference compared with other time periods (P<0.05).

CONCLUSION

The CRMS based on artificial intelligence-enabled ECG algorithm mode can significantly improve the detection rate of AMI. Moreover, small changes of ST segment in AMI patients and circadian rhythm of disease onset were presented.

Ambulatory External Electrocardiography Monitoring: Holter, Extended Holter, Mobile Cardiac Telemetry Monitoring

Ambulatory external electrocardiography (AECG) monitoring is effective as an evidence-based diagnostic tool when suspicion for cardiac arrhythmia is high. Multiple modalities of AECG monitoring exist, with unique advantages and limitations that predict effectiveness in a variety of clinical settings. Knowledge of these characteristics allows appropriate use of AECG, maximizing patient adherence, diagnostic yield, and cost-effectiveness. In addition, new technology has allowed the development of a modern generation of devices that offer increased efficacy and functionality compared with Holter monitors.

Myocardial Ischemia Induced by 5-Fluorouracil: A Prospective Electrocardiographic and Cardiac Biomarker Study

BACKGROUND

Cardiotoxicity induced by 5-fluorouracil (5-FU) is well known but poorly understood. In this study, we undertook ECG recording (Holter) and analyses of the biomarkers troponin and copeptin in patients receiving 5-FU to increase our understanding of the cardiotoxicity.

SUBJECTS, MATERIALS, AND METHODS

Patients with colorectal or anal cancer that received first-time treatment with 5-FU-based chemotherapy were prospectively included. Holter recording, clinical evaluation, 12-lead electrocardiogram, and assessment of plasma concentrations of troponin I and copeptin were performed before (control) and during 5-FU treatment (intervention).

RESULTS

A total of 108 patients were included, 82 with colorectal and 26 with anal cancer. The proportion of patients with myocardial ischemia on Holter recording was significantly higher during the first 5-FU infusion (14.1%) than before (3.7%; p = .001). The ischemic burden per day (p = .001), the number of ST depression episodes per day (p = .003), and the total duration of ischemic episodes per day (p = .003) were higher during the first 5-FU infusion than before, as was plasma copeptin (p < .001), whereas plasma troponin I was similar (p > 0.999). Six patients (5.6%) developed acute coronary syndromes and two (1.8%) developed symptomatic arrhythmias during 5-FU treatment.

CONCLUSION

5-FU infusion is associated with an increase in the number of patients with myocardial ischemia on Holter recording. According to biomarker analyses, 5-FU is associated with an increase in copeptin, but rarely with increases in cardiac troponin I. However, 5%-6% of the patients developed acute coronary syndromes during treatment with 5-FU.

IMPLICATIONS FOR PRACTICE

Symptomatic 5-fluorouracil (5-FU) cardiotoxicity occurs in 0.6%-19% of patients treated with this drug, but a small electrocardiographic (Holter) study has revealed silent myocardial ischemia in asymptomatic patients, suggesting a more prevalent subclinical cardiac influence. This study demonstrated a significant increase in the number of patients with myocardial ischemia on Holter recording during 5-FU treatment and an increase in ischemic burden. Cardiac biomarker analyses suggested that 5-FU infusion results in endogenous stress (increased copeptin) but rarely induces myocyte injury (no change in troponin). These findings suggest a more prevalent cardiac influence from 5-FU and that Holter recording is an important tool in the evaluation of patients with suspected cardiotoxicity from 5-FU.

Ambulatory and silent myocardial ischemia in women with coronary microvascular dysfunction: Results from the Cardiac Autonomic Nervous System study (CANS)

BACKGROUND

Up to two-thirds of patients with obstructive coronary artery disease (CAD) have silent ischemia (SI), which predicts an adverse prognosis and can be a treatment target in obstructive CAD. Over 50% of women with ischemia and no obstructive CAD have coronary microvascular dysfunction (CMD), which is associated with adverse cardiovascular outcomes. We aimed to investigate the prevalence of SI in CMD in order to consider it as a potential treatment target.

METHODS

36 women with CMD by coronary reactivity testing and 16 age matched reference subjects underwent 24-h 12-lead ambulatory ECG monitoring (Mortara Instruments) after anti-ischemia medication withdrawal. Ambulatory ECG recordings were reviewed by two-physician consensus masked to subject status for SI measured by evidence of ≥1 minute horizontal or downsloping ST segment depression ≥1.0 mm, measured 80 ms from the J point.

RESULTS

Demographics, resting heart rate, and systolic blood pressure were similar between CMD and reference subjects. Thirty-nine percent of CMD women had a total of 26 SI episodes vs. 0 episodes in the reference group (p = 0.002). Among these women 13/14 (93%) had SI, and few episodes (3/26, 12%) were symptomatic. Mean HR at the onset of SI was 96 ± 13 bpm and increased to 117 ± 16 bpm during the ischemic episodes. 87% reported symptoms that were not associated with ST depressions.

CONCLUSIONS

Ambulatory ischemia is prevalent in women with CMD, with a majority being SI, while most reported symptoms were not accompanied by ambulatory ischemia. Clinical trials evaluating anti-ischemic medications should be considered in the CMD population.

Ambulatory electrocardiographic monitoring as a diagnostic tool for ischemic heart disease in women

Introduction. Ischemic heart disease(IHD) is currently the leading cause of mortality in women. In this study we aimed to evaluate ambulatory electrocardiographic monitoring(AECGm) as a diagnostic test for IHD in women. Material and method. The study included 225 female who underwent AECGm divided into 2 groups: 136 previously diagnosed with IHD(IHD+) and 89 controls(IHD-). The IHD+ group was subdivided into AECGm ischemia subgroup(I+) and AECGm non-ischemia subgroup(I-). AECGm was assessed for presence of myocardial ischemia (ST segment depression >5mm), duration and ischemic load (the percentage that episodes of myocardial ischemia accounted throughout the recording). Results and discussions. Patients mean age was 62.31±12.51years. The IHD+ and IHD- groups were similar regarding associated risk factors (hypertension, obesity, dyslipidemia, diabetes mellitus), echocardiographic parameters (left ventricular size, ejection fraction, kinetic disorders), minimum and maximum heart rates(MaxHR) on AECGm. Statistically significant differences were identified regarding presence of atrial fibrillation episodes(AFibE) (IHD+:21.3% vs IHD-:8.9%), myocardial ischemia (IHD+:55.14% vs IHD-:42.69%), ischemic load (IHD+:15.23±30.54% vs IHD-:4.7±15.65%), duration of ischemia (IHD+:174.16±380.75 minutes vs IHD-:59.44 ± 209.02 minutes). In multivariate analysis, ischemia episodes, ischemic load and duration of ischemia were predicted by obesity, MaxHR and AFibE. Statistically significant differences were also identified regarding presence of AFibE (I+:30% vs I-:8.9%), MaxHR (I+:120 vs I-:111beats/minute), obesity (I+:20% vs I-:41%), diabetes mellitus (I+:16% vs I-:69%), hypertension (I+:76% vs I-:90%). Conclusions. Although myocardial ischemia was also present in IHD- group, our study demonstrated that the diagnosis of IHD can be established by AECGm using the threshold values of ischemic load (> 27%) and ischemic duration (> 315minutes).

An On-Skin Electrode with Anti-Epidermal-Surface-Lipid Function Based on a Zwitterionic Polymer Brush

On-skin flexible devices provide a noninvasive approach for continuous and real-time acquisition of biological signals from the skin, which is essential for future chronic disease diagnosis and smart health monitoring. Great progress has been achieved in flexible devices to resolve the mechanical mismatching between conventional rigid devices and human skin. However, common materials used for flexible devices including silicon-based elastomers and various metals exhibit no resistance to epidermal surface lipids (skin oil and grease), which restricts the long-term and household usability. Herein, an on-skin electrode with anti-epidermal-surface-lipid function is reported, which is based on the grafting of a zwitterionic poly(2-methacryl-oyloxyethyl, methacryloyl-oxyethyl, or meth-acryloyloxyethyl phosphorylcholine) (PMPC) brush on top of gold-coated poly(dimethylsiloxane) (Au/PDMS). Such an electrode allows the skin-lipids-fouled surface to be cleaned by simple water rinsing owing to the superhydrophilic zwitterionic groups. As a proof-of-concept, the PMPC-Au/PDMS electrodes are employed for both electrocardiography (ECG) and electromyography (EMG) recording. The electrodes are able to maintain stable skin-electrode impedance and good signal-to noise ratio (SNR) by water rinsing alone. This work provides a material-based solution to improve the long-term reusability of on-skin electronics and offers a unique prospective on developing next generation wearable healthcare devices.

Effects of silent myocardial ischemia on functional fitness and physical independence in 60–79-year-old adults

Objective

Methods

Results

Conclusion

Significant role and mechanism of microRNA-143-3p/KLLN axis in the development of coronary heart disease

Cardiovascular disease predominantly includes coronary heart disease (CHD) and stroke, results in high morbidity and mortality. MicroRNA-143-3p (miR-143-3p) is a tumor suppressor and is involved in many cancers. However, the role and mechanism of miR-143-3p in coronary heart disease is still unclear. In this study, we identified that miR-143-3p was up-regulated in rabbit CHD model. The results of TargetScan and the dual luciferase reporter assay indicated that KLLN (killin, p53 regulated DNA replication inhibitor) was a direct target of miR-143-3p. Besides, we revealed that KLLN was down-regulated in rabbit coronary heart disease model. In addition, we found that the related-markers of CHD such as TC (total cholesterol), TG (triglyceride), and LDLC (low-density lipoprotein cholesterol) in the model group were significantly increased than that in the control group. And compared with the model group, miR-143-3p inhibitor significantly reduced TC, TG, LDLC expression, while miR-143-3p mimic further increased the expression of TC, TG, and LDLC. We next found that miR-143-3p mimic promoted cell viability and migration of vascular smooth muscle cells, inhibited apoptosis; and these changes were reversed by KLLN-plasmid. And miR-143-3p inhibitor had the counter effects. Our study provided a new target for the treatment of CHD and deserves further study.

Understanding the Multitarget Pharmacological Mechanism of the Traditional Mongolian Common Herb Pair GuangZao-RouDouKou Acting on Coronary Heart Disease Based on a Bioinformatics Approach

GuangZao and RouDouKou (Fructus Choerospondiatis and Nutmeg, FCN) are one of the most common herb pairs in traditional Mongolian medicine for the treatment of coronary heart disease (CHD). However, evidence for the protective effect of FCN is limited, and its underlying mechanism of action remains unclear. The present study employed a network pharmacology approach to identify the potentially active ingredients and synergistic effects of the herb pair FCN as traditional Mongolian medicine. We predicted the targets of all available FCN ingredients with PharmMapper, SWISS, and SuperPred Server and clustered CHD-related targets from the DrugBank and the OMIM database. We also evaluated the links between herbal ingredients and pharmacological actions to explore the potential mechanism of action of FCN. We found that FCN targets a network of CHD-related key processes, including stress responses, cell adhesion and connections, angiogenesis, cell apoptosis and necrosis, the endocrine system, inflammatory and immune responses, and other biological processes. To confirm the predicted results, we investigated the protective effect of FCN on isoproterenol- (ISO-) induced myocardial ischemia in rats. Pathological assessment indicated that FCN inhibits apoptosis and inflammatory responses involving the myocardium. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting analyses demonstrated the therapeutic effects of FCN on ISO-induced myocardial ischemia rats, possibly via regulating stress and inflammatory responses and inhibiting cardiomyocyte apoptosis. The findings of the present study indicate that bioinformatics combined with experimental verification provide a credible and objective method to elucidate the complex multitarget mechanism of action of FCN.

Risk factors for silent myocardial ischemia in patients with well-controlled essential hypertension

Silent myocardial ischemia (SMI) is frequently observed in patients with essential hypertension (EH). The major risk factor for SMI is uncontrolled blood pressure (BP), but SMI is also observed in patients with well-controlled BP. To evaluate the prevalence of SMI and the factors associated with SMI in EH patients with well-controlled BP. The medical records of 859 EH patients who underwent simultaneous 24-h ambulatory blood pressure monitoring (ABPM) and 24-h ambulatory electrocardiogram recording (AECG) were retrospectively evaluated. Each SMI episode was characterized by: (a) ST segment depression ≥0.5 mm; (b) duration of ST segment depression >60 s; and (c) reversibility of the ST segment depression. Overall 126 EH patients (14.7 %) had at least one episode of SMI. The SMI events were more frequent among patients with poorly controlled compared to those with well-controlled BP [86/479 (17.95 %) vs. 40/380 (10.52 %), p < 0.01]. Among EH patients with well-controlled BP, current and past smoking as well as the presence of an additional metabolic syndrome (MetS) constitutive element (obesity, impaired fasting glucose level or dyslipidemia) were significantly associated with the occurrence of SMI. In all EH patients with well-controlled BP and AECG evidence of SMI, there were one or more coronary artery stenotic lesions greater than 50 % found at coronary angiography. In EH patients who are current smokers, or have one or more additional components of a MetS there is markedly reduced benefit associated with good BP control with regard to the occurrence of myocardial ischemia: in this patient category, an AECG may help detect this condition.

[Triple antianginal combinations in the treatment of elderly and senile patients with stable angina]

AIM

To compare the efficiency and safety of antianginal therapy (AAT) using a combination of bisoprolol, ivabradine, and trimetazidine or ranolazine in elderly and senile patients with stable angina.

SUBJECTS AND METHODS

The study enrolled 107 patients aged 60 to 79 years with coronary heart disease and Functional Class II and III angina. When the patients taking bisoprolol 1.25-2.5 mg once daily and ivabradine 2.5-7.5 mg twice daily continued to have angina and/or silent myocardial ischemia, after randomization 54 patients received an additional 35 mg of trimetazidine twice a day and 53 patients had ranolazine 500 mg twice daily. A comprehensive clinical and instrumental study was conducted prior to randomization and after 6 months of triple AAT.

RESULTS

The patients tolerated well both treatments that substantially improved the results of a treadmill exercise test. Trimetazidine reduced to a greater extent the duration of silent ST-segment depression, as evidenced by Holter monitoring. Trimetazidine and ranolazine comparably improved left ventricular systolic and diastolic function, large arterial structure and function, and quality of life in the patients.

CONCLUSION

The combinations of the low-dose β-blocker with ivabradine and trimetazidine or ranolazine may be used to treat refractory stable angina in elderly and senile patients. Trimetazidine is preferred due to its higher efficacy in treating silent myocardial ischemia and to its lower cost.

Monitoring and analysis of vital signs of a patient through a multi-agent application system

In the medical environment, the clinical study of the most basic vital signs of a patient represents the simplest and most effective way to detect and monitor health problems. There are many diseases that can be diagnosed and controlled through regular monitoring of these medical data. The purpose of this study is to develop a monitoring and tracking system for the various vital signs of a patient. In particular, this work focuses on the design of a multi-agent architecture composed of virtual organizations with capabilities to integrate different medical sensors on an open, low-cost hardware platform. This system integrates hardware and software elements needed for the routine measurement of vital signs, performed by the patient or caregiver without having to go to a medical center.