Electrocardiogram Changes Research Articles

Advancements and Applications of Convolutional Neural Network Models in Cardiovascular Disease: A Comprehensive Review

In recent years, artificial intelligence (AI) has demonstrated remarkable advancements in the field of cardiovascular disease (CVD), particularly in the analysis of electrocardiograms (ECGs). Due to its widespread use, low cost, and high efficiency, the ECG has long been regarded as a cornerstone of cardiological examinations and remains the most widely utilized diagnostic tool in cardiology. The integration of AI, especially deep learning (DL) technologies based on convolutional neural networks (CNNs), into ECG analysis, has shown immense potential across several cardiological subfields. Deep learning methods have provided robust support for the rapid interpretation of ECGs, enabling the fine-grained analysis of ECG waveform changes with diagnostic accuracy comparable to that of expert cardiologists. Additionally, CNN-based models have proven capable of capturing subtle ECG changes that are often undetectable by traditional methods, accurately predicting complex conditions such as atrial fibrillation, left and right ventricular dysfunction, hypertrophic cardiomyopathy, acute coronary syndrome, and aortic stenosis. This highlights the broad application potential of AI in the diagnosis of cardiovascular diseases. However, despite their extensive applications, CNN models also face significant limitations, primarily related to the reliability of the acquired data, the opacity of the “black box” processes, and the associated medical, legal, and ethical challenges. Addressing these limitations and seeking viable solutions remain critical challenges in modern medicine.

Clinical implication of electrocardiogram change in patients experiencing lung transplantation with end stage lung disease

IntroductionEnd-stage lung disease causes cardiac remodeling and induces electrocardiogram (ECG) changes. On the other way, whether lung transplantation (LTx) in end-stage lung disease patients are associated with ECG change is unknown. The object of this study was to investigate ECG changes before and after LTx in end-stage lung disease patients and whether these changes had clinical significance.MethodThis was a single-center retrospective cohort study of 280 end-stage lung disease patients who consecutively underwent LTx at a tertiary referral hospital. ECG findings before LTx and within 1 week and 1, 3, and 6 months after LTx were obtained and analyzed. To find clinical meaning, the ECG at 1 month after LTx was analyzed according to 1-year survival (survivor vs non-survivor groups). Survival data were estimated using the Kaplan–Meier method.ResultsSignificant differences were observed in the PR interval, QRS duration, QT interval, QTc interval, and heart rate before LTx and 1 month after LTx; the PR interval, QRS duration, QTc interval, and heart rate were decreased. Particularly, the QTc interval was significantly decreased 1 month after LTx, whereas there was no significant change in the QTc interval from 1 to 6 months thereafter. The PR interval, QT interval, QTc interval, and heart rate were significantly different between the survivor and non-survivor groups. The serial changes in QTc interval before LTx and 1 and 3 months after LTx were also significantly different between the survivor and non-survivor groups (p = 0.040 after adjusting for age and body mass index). Upon dividing the patients based on the range of QTc interval change ≤ -8 ms, >-8–10 ms, >10–35 ms, >35 ms), the survival rate was significantly lower in the group whose QTc interval at 1 month after LTx decreased by > 35 m (p = 0.019).ConclusionLTx in patients with end-stage lung disease may induce ECG changes. Patients whose QTc interval at 1 month after LTx decreased by > 35 ms have a significantly higher 1-year mortality rate. Hence, these ECG changes may have clinical and prognostic significance.

Sulcardine, an investigational multichannel blocker for atrial fibrillation with uniquely intense JTp inhibition to enhance safety

Abstract Background Sulcardine is a multi-ion channel blocker for treating atrial fibrillation (AF) with similar inhibitory potency on peak/late sodium, L-type calcium, and rapidly activating delayed-rectifier potassium (IKr) currents. The therapeutic effect of inhibiting IKr includes QT prolongation (accompanied by a proportional J to T peak [JTp] interval prolongation), which, when excessive, may cause malignant arrhythmias. As previously reported, sulcardine strongly mitigates the JTp increase that may contribute to excessive QT prolongation by inhibiting late sodium and L-type calcium currents, an intrinsic mechanism to protect from excessive IKr block. Purpose We explored the JTp mechanism, pharmacokinetics (PK), electrocardiogram (ECG) changes, safety, and drug-drug interaction (DDI) of a single sulcardine (as HBI-3000) intravenous (IV) infusion in healthy subjects. Methods An open-label Phase 1 study evaluated the PK interaction between sulcardine, dosed as a 350 mg 30-minute infusion of the sulfate salt HBI-3000, and a cytochrome P450 CYP2D6 enzyme inhibitor (paroxetine). Triplicate ECGs were extracted from continuous 12-lead Holter ECG recordings at baseline and 10 time points thereafter. Mean baseline-subtracted and heart rate-corrected QTcF (dQTcF), JTpc (dJTpc), and other ECG changes were calculated at each time point. Left ventricular ejection fraction (LVEF) was assessed at baseline, 30-, and 120-minutes post-infusion start by transthoracic echocardiography (TTE). Results 39 subjects received HBI-3000, 33 in the paired PK population. Expected ECG parameter changes proportional to sulcardine plasma concentrations were observed in the HBI-3000-alone portion of the study, including modest QTcF prolongation (Fig 1, blue slope, confidence band) and JTpc inhibition (Fig 1, red). The usual JTpc increase associated with IKr blockers, even those with mitigating channel block (such as the late sodium current), was not only reduced but actually reversed. We calculated the dQTcF change that would have been observed in the absence of JTpc reduction by sulcardine (Fig 1, green). Sulcardine reduced the QTcF increase that might have occurred by about 21 msec at the highest concentrations, and this mitigating effect was observed at all concentrations. No clinically significant safety findings or arrhythmias were observed. The most frequent TEAEs were nausea and headache (n=2 each [5.1%]). No LVEF changes were clinically significant. Sulcardine had minimal metabolic interactions. Conclusion Acute IV HBI-3000 administration resulted in no clinically significant safety findings, LVEF depression, or DDI with CYP2D6. Sulcardine facilitates QT prolongation, which has a therapeutic benefit in terminating AF, with simultaneous uncoupling and reversing of the JTpc interval increase, a potential mechanism for reducing proarrhythmic risk due to excessive QT prolongation.Figure 1.ECG Intervals vs Sulcardine Conc

Accurate detection of dilated cardiomyopathy onset through machine learning predictions from ECG data

Abstract Background Dilated cardiomyopathy (DCM) is a primary heart muscle disease characterised by left-ventricular dilatation and reduced contractility, often associated with arrhythmia and conduction disease. DCM often has a genetic component, putting family members of diagnosed patients at risk for the disease. Stratification tools to provide personalized screening advice are currently lacking. Artificial intelligence (AI) based analysis of the electrocardiogram (ECG) offers a potential solution to this challenge. Purpose Our study aims to develop and validate a novel AI-ECG model capable of prediction and early detection of DCM. Methods An AI-ECG model was developed on a United States (US) based secondary care centre dataset including 337,463 ECGs from 50,932 patients within 4 months of diagnostic echocardiography and 265,576 ECGs from 51,086 patients prior to the first diagnostic echo. The data was split 50/10/40% for training, validation, and testing, with each subset containing 9-12% DCM positive labels. The model architecture was based on a convolutional neural network with residual blocks with a modified final layer for a discrete-time survival model. The AI-ECG score was linked to changes in the median ECG within the test set to provide explainability. External validation was performed on 68,885 diagnostic ECGs (0.08% DCM positive) from the UK biobank (UKB) and a Chinese general hospital dataset with 317,854 diagnostic ECGs (2.2% DCM positive) and 76,936 predictive ECGs (1.7% DCM positive). We performed common and rare variant association studies for the AI ECG scores on quality-controlled UKB data. Results The AI-ECG score for predicted future DCM was associated with diverse ECG features (Fig. 1). In the US cohort test set, the model achieved high diagnostic accuracy with an AUC of 0.9 (95% CI 0.89-0.90) overall, and 0.89 (0.85-0.92) in a subset excluding ischemic or valvular heart disease. External datasets showed AUCs of 0.86 (0.81-0.91) in the UKB and 0.97 (96-0.97) in the Chinese dataset. The predictive performance of the AI-ECG score, adjusted for age and sex, closely approximated echocardiographic traits (LVEF and LVEDD, Fig. 2) with a concordance index (CI) of 0.79 (0.76-0.83) and 0.81 (0.77-0.85), respectively, at 10 years of follow up (FU). Combining AI-ECG scores with echocardiographic traits enhanced the CI to 0.84 (0.8-0.87). Similar findings were observed in the Chinese dataset, with a CI of 0.87 (0.85-0.89) for the AI-ECG score and 0.9 (0.88-0.92) for echocardiographic traits. Genetic analyses in UKB identified associations between the AI-ECG score and rare TTN variants as well as 25 common variant loci. Conclusion Our explainable AI ECG model for future DCM prediction demonstrates robust performance across datasets, providing comparable predictive accuracy to echocardiographic traits up to 10 years pre-diagnosis. Genetic associations support the model's validity and provide new tools for DCM genetic discovery.

Clinical predictive value of PD-1/PD-L1-induced electrocardiogram changes for cardiotoxicity

Objective: To observe the electrocardiogram (ECG) changes of programmed death receptor 1 (PD-1)/programmed death receptor-ligand 1 (PD-L1) immune checkpoint inhibitors before and after immunotherapy of patients during clinical antitumor process, and to explore the occurrence and influencing factors of cardiotoxicity of immune checkpoint inhibitors. Methods: A total of 93 patients with locally advanced or metastatic solid tumors confirmed by pathological diagnosis in Cancer Hospital of Chinese Academy of Medical Sciences from October 1, 2019 to September 30, 2020 were selected and treated with PD-1/PD-L1 inhibitor monotherapy. Groups were divided according to immunotherapy regimen: Group A (drug code: 609A), 16 patients were given 1 mg/kg of the drug for 21 days; Group B (drug code: HX008), 23 patients were treated with 200mg for 21 days; Group C (drug code: GB226), 28 patients were treated with 3mg/kg for 14 days; Group D (drug code: LP002), 26 patients were treated with 900mg for 14 days. The patients were monitored and followed up for 10 cycles. The ECG results of each group were recorded, and the correlation between ECG abnormality and cardiotoxicity was analyzed. Results: A total of 75 patients showed abnormal ECG that met the diagnostic criteria. There was no significant difference in abnormal ECG rate after immunotherapy in group A (P＞0.05), while the incidence of adverse cardiac events increased after immunotherapy in group B (P＜0.05), and the abnormal ECG rate increased significantly after chemotherapy in group C and group D. There was statistical difference before and after immunotherapy (P＜0.001). The number of abnormal cases in group A (8 cases, 50.0%, 8/16) was significantly lower than that of group B (20 cases, 87.0%, 20/23). The number of abnormal cases in group C and group D was 24 (85.7%) and 23 (88.4%), respectively, without statistical difference (P＞0.05), but their abnormal rates of ECG were higher than that in group A. The incidence of electrical adverse events in immunotherapy center of patients with underlying diseases was 1.93 times higher than that of patients without underlying diseases. The incidence of central electrical adverse events during immunotherapy in group B, C and D was 6.667, 6.000 and 7.667 times higher than that in group A, respectively. Conclusions: The high sensitivity of early ECG changes induced by immune checkpoint inhibitors enables early prediction of related cardiotoxicity. The presence or absence of comorbid underlying disease and drug dosage are correlated with the occurrence of adverse cardiac events, and these early changes provide a evidence for clinical treatment and prevention.

Diagnostic value of nocturnal trend changes in a dynamic electrocardiogram for coronary heart disease

ObjectiveTo explore the diagnostic value of intermittent changes in the nocturnal ST segment trend graph in a dynamic electrocardiogram (ECG) for coronary heart disease (CHD).MethodsA total of 205 patients who underwent coronary angiography were included in this retrospective study. The study sample was determined through a power analysis aimed at achieving power of 80% with a significance level of 0.05. The participants were divided into the CHD (n = 101) and the non-CHD (n = 104) group, based on the degree of coronary artery diameter stenosis. The morphological changes in the ST segment trend graph were observed and divided into two categories: ‘wall-shaped’ and ‘peak-shaped’ changes.ResultsAmong the 205 patients, 94 had nocturnal ST segment dynamic changes and 111 did not. The detection rate of CHD without nocturnal ST segment dynamic changes was 21.59%, significantly lower than the detection rate of 93.18% in those with nocturnal ST segment changes, reflecting a statistically significant difference (P < 0.05). The positive rate of ST segment in patients with single-vessel disease (71.88%) was lower than in patients with multi-vessel disease (78.57%), and both differences were statistically significant (P < 0.05). The duration of ST segment trend graph changes in 94 cases in the CHD group with intermittent changes in the nocturnal ST segment trend graph was higher than in the non-CHD group, but no significant difference was observed (P > 0.05). The detection rate of CHD in the peak-shaped dynamic change group of the nocturnal ST segment trend graph was significantly higher (76/82) than in the wall-shaped (6/82) dynamic change group (P < 0.05).ConclusionPeak-shaped changes in the nocturnal ST segment trend graph indicate coronary artery lesions. Nocturnal ST segment changes observed through dynamic ECG monitoring can serve as a valuable non-invasive predictor for CHD, providing a feasible method for early diagnosis and intervention in clinical practice.

Artificial intelligence evaluation of electrocardiographic characteristics and interval changes in transgender patients on gender-affirming hormone therapy

Abstract Aims Gender-affirming hormone therapy (GAHT) is used by some transgender individuals (TG), who comprise 1.4% of US population. However, the effects of GAHT on electrocardiogram (ECG) remain unknown. The objective is to assess the effects of GAHT on ECG changes in TG. Methods and results Twelve-lead ECGs of TG on GAHT at the Mayo Clinic were inspected using a validated artificial intelligence (AI) algorithm. The algorithm assigns a patient’s ECG male pattern probability on a scale of 0 (female) to 1 (male). In the primary analysis, done separately for transgender women (TGW) and transgender men (TGM), 12-lead ECGs were used to estimate the male pattern probability before and after GAHT. In a subanalysis, only patients with both pre- and post-GAHT EGCs were included. Further, the autopopulated PR, QRS, and QTc intervals were compared before and after GAHT. Among TGW (n = 86), the probability (mean ± SD) of an ECG male pattern was 0.84 ± 0.25 in the pre-GAHT group, and it was lowered to 0.59 ± 0.36 in the post-GAHT group (n = 173, P &amp;lt; 7.8 × 10−10). Conversely, among TGM, male pattern probability was 0.16 ± 0.28 (n = 47) in the pre-GAHT group, and it was higher at 0.41 ± 0.38 in the post-GAHT group (n = 53, P &amp;lt; 2.4×10−4). The trend persisted in the subanalysis. Furthermore, both the PR (P = 5.68 × 10−4) and QTc intervals (P = 6.65×10−6) prolonged among TGW. Among TGM, the QTc interval shortened (P = 4.8 × 10−2). Conclusion Among TG, GAHT is associated with ECG changes trending towards gender congruence, as determined by the AI algorithm and ECG intervals. Prospective studies are warranted to understand GAHT effects on cardiac structure and function.

Cardiovascular effects and clinical outcomes in acute opioid toxicity: A case-control study from Port Said and Damietta Governorates Egypt

Substance abuse, particularly opioid intoxication, presents a significant public health challenge, leading to severe cardiovascular complications. This case-control study assessed the cardiac profile and clinical outcomes of 51 patients with confirmed acute opioid toxicity, compared to 51 control participants, in general hospitals across Port Said and Damietta governorates, Egypt. The study revealed that opioid-intoxicated patients exhibited significant cardiovascular abnormalities, including hypotension (39.2 %) and electrocardiogram (ECG) changes (72.5 %), with sinus bradycardia (51 %) being the most common. Additionally, echocardiographic abnormalities were found in 40 % of cases, with abnormal regional wall motion and valvular defects observed in several patients. Elevated levels of cardiac enzymes, such as Troponin-I and CK-MB, were significantly correlated with increased ICU stay length and higher mortality rates. The most common morbidities included coma (64.7 %) and shock (39.2 %). The study underscores the critical need for early cardiac assessment in opioid-intoxicated patients to predict clinical outcomes and guide therapeutic interventions.

Safety and Usefulness of Intracoronary Acetylcholine 200 μg Into the Left Coronary Artery as Vasoreactivity Testing: Comparisons With Intracoronary Acetylcholine Maximum 100 μg.

We retrospectively analyzed the usefulness and safety of intracoronary acetylcholine (ACh) 200 μg into the left coronary artery (LCA) as vasoreactivity testing compared with intracoronary ACh 100 μg. We recruited 1433 patients who had angina-like chest pain and intracoronary ACh testing in the LCA, including 1234 patients with a maximum ACh 100 μg and 199 patients with a maximum ACh 200 μg. ACh was injected in incremental doses of 20/50/100/200 μg into the LCA. Positive spasm was defined as ≥ 90% stenosis, usual chest pain, and ischemic electrocardiogram (ECG) changes. The incidence of coronary constriction ≥ 90%, usual chest pain, and ischemic ECG changes with a maximum ACh of 100 μg was markedly higher than that with a maximum ACh of 200 μg. The frequency of unusual chest pain in patients with a maximum ACh of 200 μg was higher than that in those with a maximum ACh of 100 μg (13% vs. 3%, p < 0.001). In patients with rest angina, positive spasm of maximum ACh 100 μg was significantly higher than that of maximum ACh 200 μg, whereas there was no difference regarding positive spasm in patients with atypical chest pain between the two ACh doses. Major complications (1.38% vs. 1.51%, p = 0.8565) and the occurrence of paroxysmal atrial fibrillation (1.81% vs. 2.63%, p = 0.6307) during ACh testing in the LCA were not different between the two maximum ACH doses. Intracoronary ACh 200 μg into the LCA is clinically useful and safe for vasoreactivity testing when intracoronary ACh 100 μg dose not provoke spasms.

Transseptal Transition Patterns DuringLeft Bundle Branch Area LeadImplantation.

Continuous deep septal pacing and signal recording during implantation of left bundle branch pacing (LBBP) lead enables to monitor beat-to-beat changes of electrocardiogram (ECG) and myocardial current of injury (COI) as the lead crosses the septum. This study aimed to characterize patterns of continuous QRS, ST-T, and COI change for monitoring of the lead depth and instantaneous determination of the obtained capture type (LBBP vs left ventricular septal pacing [LVSP]). The ECG and COI during lead implantation were scrutinized for sudden changes of V6 R-wave peak time, V1initial and terminal R-wave amplitude, V3-V6 R-wave amplitude, repolarization pattern and S-wave amplitude in I, V5-V6, and COI drop. The sudden and gradual transition patterns were diagnosed depending on the presence or absence of the above beat-to-beat ECG phenomena, respectively. A total of 212 pacemaker recipients were analyzed; LBBP and LVSP were obtained in 77.4% and 22.6%, respectively. There were 4.7 ± 2.1 and 0.2 ± 0.6 beat-to-beat phenomena in LBBP and LVSP patients, respectively. The sudden transition pattern, recognized in 80.7%, had sensitivity and specificity for LBBP diagnosis of 98.8% and 81.2%, respectively. A sudden drop of COI (29.4 ± 8.5mV to 12.8 ± 4.9mV) was observed in 53.9% patients (LBBP was simultaneously obtained in 92.7%). Capture of left bundle branch during lead penetration is a beat-to-beat phenomenon. Two transseptal transition patterns were identified: 1) sudden, which is typical for obtaining LBBP; and 2) gradual, which is typical for obtaining LVSP. A sudden COI drop, a very observable phenomenon, also identified reaching the left subendocardial area.

Athlete's ECG Made Easy: A Practical Guide to Surviving Everyday Clinical Practice.

Electrocardiogram modifications in athletes are common and usually reflect structural and electrical heart adaptations to regular physical training, known as the athlete's heart. However, these electrical modifications sometimes overlap with electrocardiogram findings that are characteristic of various heart diseases. A missed or incorrect diagnosis can significantly impact a young athlete's life and potentially have fatal consequences during exercise, such as sudden cardiac death, which is the leading cause of death in athletes. Therefore, it is crucial to correctly distinguish between expected exercise-related electrocardiogram changes in an athlete and several electrocardiogram abnormalities that may indicate underlying heart disease. This review aims to serve as a practical guide for cardiologists and sports clinicians, helping to define normal and physiology-induced electrocardiogram findings from those borderlines or pathological, and indicating when further investigations are necessary. Therefore, the possible athlete's electrocardiogram findings, including rhythm or myocardial adaptation, will be analyzed here, focusing mainly on the differentiation from pathological findings.

Comparative Study Of Standard Drug Dose Mixture Versus Fentanyl In Attenuating Stress Response During Laryngoscopy And Tracheal Intubation In Neurosurgery: A Prospective Observational Study

Background: Opioid-free anesthesia (OFA) is gaining prominence, particularly in neurosurgery, due to its potential to minimize opioid-related complications such as postoperative nausea and vomiting (PONV) and shivering. This Prospective observational study aims to compare the efficacy of a standard drug dose mixture comprising intravenous magnesium sulphate, lignocaine, paracetamol, and tramadol with fentanyl in attenuating the hemodynamic stress response during laryngoscopy and tracheal intubation. Methods: Sixty neurosurgical patients, aged 18 to 60 years, undergoing cervical or lumbar discectomies under general anesthesia in our institute were divided into two groups. One group received the standard drug dose mixture, and the other received fentanyl. Hemodynamic parameters, including pulse rate, blood pressure, oxygen saturation (SpO2), and electrocardiogram (ECG) changes, were recorded at baseline, during intubation, and at one- minute intervals for five minutes post-intubation. Results: Both groups demonstrated stable hemodynamics with no significant differences in pulse rate or blood pressure. No ECG abnormalities were observed, and SpO2 remained above 96% in all patients. Additionally, the standard drug dose mixture group showed a reduced incidence of PONV and shivering compared to the fentanyl group. Conclusion: The standard drug dose mixture provides a safe and effective alternative to fentanyl for attenuating the hemodynamic stress response during laryngoscopy and tracheal intubation, with fewer side effects. Further randomized controlled trials are recommended to confirm these findings and explore the benefits of opioid-free anesthesia in various surgical procedures.

Cardiac effects of COVID-19 infection in children.

It is known established that the cardiac effects of COVID-19 infection are associated with poor prognosis and high mortality rates in infected patients. The aim of this study was to evaluate the cardiac effects of COVID-19 infection in paediatric patients and identify the correlations between clinical and laboratory data and the degree of cardiac involvement. A retrospective data analysis was conducted on 64 paediatric patients at Gazi University Department of Pediatrics who were treated as inpatients with a diagnosis of COVID-19. Patients were classified as "COVID-19-related cardiac involvement cases" if their electrocardiogram and echocardiogram results indicated a pathology and/or if their laboratory data indicated increased cardiac enzymes. All patients were divided into subgroups based on whether they had cardiac involvement and whether they were diagnosed with multisystem inflammatory syndrome in children. In comparison to patients who did not have cardiac involvement, those with cardiac involvement had significantly higher levels of hs-Troponin T, Pro-BNP, and D-dimer. Patients with multisystem inflammatory syndrome in children had significantly longer PR intervals than those without multisystem inflammatory syndrome in children (p = 0.0001). Patients with multisystem inflammatory syndrome in children had a significantly higher rate of pathological valve insufficiencies (68.1%) than those without multisystem inflammatory syndrome in children (14.2%) (p = 0.001). In our study, the strongest predictive biomarker of cardiac involvement in paediatric patients with COVID-19 infection was determined to be hs-Troponin T. It was observed that pathologic electrocardiogram changes could reflect cardiac involvement in the absence of any other signs. Patients with multisystem inflammatory syndrome in children exhibited significantly greater rates of pathologic echocardiogram findings and myocardial dysfunction than those without multisystem inflammatory syndrome in children. In all patients, pathologic electrocardiogram and echocardiogram findings were found to be strongly associated with the severity of inflammation.

Hypothesis paper: GDF15 demonstrated promising potential in Cancer diagnosis and correlated with cardiac biomarkers

BackgroundCardiovascular toxicity represents a significant adverse consequence of cancer therapies, yet there remains a paucity of effective biomarkers for its timely monitoring and diagnosis. To give a first evidence able to elucidate the role of Growth Differentiation Factor 15 (GDF15) in the context of cancer diagnosis and its specific association with cardiac indicators in cancer patients, thereby testing its potential in predicting the risk of CTRCD (cancer therapy related cardiac dysfunction).MethodsAnalysis of differentially expressed genes (DEGs), including GDF15, was performed by utilizing data from the public repositories of the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). Cardiomyopathy is the most common heart disease and its main clinical manifestations, such as heart failure and arrhythmia, are similar to those of CTRCD. Examination of GDF15 expression was conducted in various normal and cancerous tissues or sera, using available database and serum samples. The study further explored the correlation between GDF15 expression and the combined detection of cardiac troponin-T (c-TnT) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP), assessing the combined diagnostic utility of these markers in predicting risk of CTRCD through longitudinal electrocardiograms (ECG).ResultsGDF15 emerged as a significant DEG in both cancer and cardiomyopathy disease models, demonstrating good diagnostic efficacy across multiple cancer types compared to healthy controls. GDF15 levels in cancer patients correlated with the established cardiac biomarkers c-TnT and NT-proBNP. Moreover, higher GDF15 levels correlated with an increased risk of ECG changes in the cancer cohort.ConclusionGDF15 demonstrated promising diagnostic potential in cancer identification; higher GDF15, combined with elevated cardiac markers, may play a role in the monitoring and prediction of CTRCD risk.

Six transition patterns and seven capture types in different left bundle branch bipolar pacing configurations.

This study aims to explore the different transition patterns and capture types during two bipolar pacing tests based on the selective left bundle branch (LBB) capture determined by the continuous pacing and recording technique. In total, 67 patients completed two unipolar and two bipolar pacing tests based on selective LBB capture during screwing-in for left bundle branch pacing (LBBP) using the continuous pacing and recording technique. The electrophysiological characteristics and potential mechanisms of different pacing configurations were further evaluated in this study. We found six transition patterns and derived seven capture types in two bipolar pacing tests according to the analysis of continuous electrocardiogram and electrogram changes. Compared with the conventional configuration of "Tip-Ring+" bipolar pacing, "Ring-Tip+" testing had a lower threshold for simultaneous capture of the LBB and the left and right ventricular septum myocardium (1.57 vs. 2.84 V at 0.5 ms) and was the only configuration to yield the peculiar "LBBP + right ventricular septum pacing (RVSP)" capture type. In this study, we observed for the first time that "Ring-Tip+" bipolar pacing allows for a lower clinically applicable pacing threshold for simultaneous capture of the LBB and left and right ventricular septum myocardium, and the peculiar "LBBP + RVSP" capture type. This may be a more advantageous physiological pacing configuration, warranting further investigation and application in the future. Based on the specific selective LBB capture, we first found six transition patterns and derived seven capture types in two bipolar pacing tests due to the different thresholds of the LBB, left ventricular septal myocardial, and right ventricular septal myocardial. Compared with the conventional configuration of "Tip-Ring+" bipolar pacing, "Ring-Tip+" testing had a lower threshold for simultaneous capture of the LBB and the left and right ventricular septum myocardium (1.57 vs. 2.84 V at 0.5 ms) and was the only configuration to yield the peculiar "LBBP + RVSP" capture type. More pacing strategies should be released and investigated to achieve the best physiological pacing according to the individualized electrophysiological characteristics of patients.

β-Adrenergic receptor signalling pathway mediated antiarrhythmic activity of s-limonene in the rat heart.

S-Limonene (s-Lim) is a monocyclic monoterpene found in a variety of plants and has been shown to present antioxidant and cardioprotective activity in experimental models of myocardial infarction. The aim of this study was to evaluate the potential mechanism by which s-Lim exerts its antiarrhythmic effect, focusing on the blockade of β-adrenoceptor (β-AR) and its effects on various in vivo and in vitro parameters, including electrocardiogram (ECG) measurements, left ventricular developed pressure (LVDP), the β-adrenergic pathway, sarcomeric shortening and L-type calcium current (ICa,L). In isolated hearts, 10 μM of s-Lim did not alter the ECG profile or LVPD. s-Lim increased the heart rate corrected QT interval (QTc) (10.8%) at 50 μM and reduced heart rate at the concentrations of 30 (12.4%) and 50 μM (16.6%). s-Lim (10 μM) also inhibited the adrenergic response evoked by isoproterenol (ISO) (1 μM) reducing the increased of heart rate, LVDP and ECG changes. In ventricular cardiomyocyte, s-Lim antagonized the effect of dobutamine by preventing the increase of sarcomeric shortening, demonstrating a similar effect to atenolol (blocker β1-AR). In vivo, s-Lim antagonized the effect of ISO (agonists β1-AR), presenting a similar effect to propranolol (a non-selective blocker β-AR). In ventricular cardiomyocyte, s-Lim did not alter the voltage dependence for ICa,L activation or the ICa,L density. In addition, s-Lim did not affect changes in the ECG effect mediated by 5 μM forskolin (an activator of adenylate cyclase). In an in vivo caffeine/ISO-induced arrhythmia model, s-Lim (1 mg/kg) presented antiarrhythmic action verified by a reduced arrhythmia score, heart rate, and occurrence of ventricular premature beats and inappropriate sinus tachycardia. These findings indicate that the antiarrhythmic activity of s-Lim is related to blockade of β-AR in the heart.

Electrocardiographic Criteria for the Diagnosis of Acute Myocardial Infarction in Patients with Left Bundle Branch Block

During normal conduction system, the first segment depolarized is interventricular septum, normal ventricular depolarization begins with the septal fascicle of the left bundle branch followed by a simultaneous depolarization of the remaining ventricular walls from endocardium to pericardium via the right and left bundle branches. In left bundle branch block (LBBB) condition, the left ventricular activation is delayed, and the initial septal activation is from right to left, secondary ST segment and T wave abnormalities occur, and septal Q waves indicative of an MI are absent. About 0.5 percent of patients with acute myocardial infarction had left bundle-branch block Patients with left bundle branch block (LBBB) and suspected of acute myocardial infarction (MI) is challenge to the clinician. A diagnosis of MI with electrocardiogram (ECG) is especially difficult in the setting of LBBB because of the characteristic ECG changes caused by altered septal and left free wall ventricular depolarization. Here we review the pathophysiology of LBBB in MI, highlight evolving paradigms for the diagnosis of suspected MI in patients with LBBB.

Real-time analysis of conduction disturbances during TAVR with the CARA monitor

BackgroundThe occurrence of conduction disturbances (CDs) remains the most frequent complication of transcatheter aortic valve replacement (TAVR). However, little is known about the timing of electrocardiogram (ECG) changes and CDs during the TAVR procedure. ObjectiveThe objective of this study was to describe ECG changes throughout the TAVR procedure using the CARA monitor. MethodsThis was a multicenter study including 196 prospectively enrolled patients with no CDs undergoing TAVR. All patients were monitored with the CARA system, which uses a 12-lead ECG to measure PQ and QRS intervals, QRS axis, and variations with each heartbeat at every step: baseline, wire insertion, pre-dilatation, valve deployment, post-dilatation, and end of procedure. ResultsPQ and QRS intervals progressively increased throughout the procedure, with a cumulative increase from 169.0 ± 20.0 ms to 186.0 ± 31.6 ms (P < .001) for the PQ interval and from 101.3 ± 10.5 ms to 126.0 ± 25.4 ms (P < .001) for the QRS interval, from baseline to the end of the procedure. A significant increase in the number of patients with left axis deviation was observed (8% at baseline vs 32% at end of procedure; P < .001). A total of 161 (82.4%) patients exhibited at least 1 CD episode (PQ >200 ms, QRS ≥120 ms, advanced heart block) during the procedure, with most episodes occurring during pre-dilatation and valve implantation maneuvers. ConclusionThe CARA system facilitated real-time ECG monitoring, detecting subtle and progressive changes during TAVR. ECG changes occurred at each step, with most patients experiencing CDs, especially during pre-dilatation and valve implantation. The potential of ECG dynamics and timing for early detection of severe CDs should be explored in future studies.

The Effect of Foot Reflexology on Fatigue, Sleep Quality, Physiological Indices, and Electrocardiogram Changes in Patients with Acute Myocardial Infarction: A Randomized Clinical Trial.

Limited evidence is available regarding the effect of reflexology on Acute Myocardial Infarction (AMI). The present study evaluated the effect of foot reflexology on fatigue, sleep quality, physiological indices, and electrocardiogram changes in AMI. This clinical trial was conducted on 80 subjects with AMI. They were divided into an intervention (received reflexology for 3 consecutive days) and a control (received the routine care) group. The Multidimensional Fatigue Inventory, the Pittsburgh Sleep Quality Index, a pain numeric analog scale, a daily physiological indices form, and daily electrocardiogram were used to collect data. The collected data were analyzed in SPSS software. The study was conducted based on CONSORT criteria. After controlling the covariates, a significant difference was found between the intervention and control groups with regard to the mean scores of fatigue (F5,80 = 16.33; p < 0.001), sleep quality (F5,80 = 16.56; p < 0.001), and chest pain intensity (F5,80 = 6.86; p = 0.010); means of systolic blood pressure (F5,80 = 22.20; p < 0.001), heart rate (F5,80 = 5.86; p = 0.010), respiration (F5,80 = 9.37; p = 0.003), and temperature (F5,80= -4.23; p < 0.001); and incidence of ST-segment (χ2 1,80 = 5.00; p = 0.020) and T-wave changes (χ2 1,80 = 6.05, p = 0.010) on the fourth day of the intervention. Given the effectiveness of foot reflexology in different aspects of AMI patients, the implementation of this intervention is recommended for these patients in coronary care units.

Comparison of Systemic Exposure Between Epinephrine Delivered via Metered-Dose Inhalation and Intramuscular Injection.

Background: Primatene® MIST, an epinephrine metered-dose inhaler (MDI), has long been questioned by some medical professionals for asthma treatment despite having been approved by the Food and Drug Administration. One of the primary reasons for their concerns stemmed from potential cardiovascular complications following epinephrine administration. However, the majority of documented cardiovascular complications seemed to occur following the injection route of the epinephrine. The aim of this study was to evaluate the systemic exposure of epinephrine delivered through different administration routes and to understand its relationship with cardiovascular effects. Since albuterol inhalers are commonly recommended for asthma, albuterol was also studied as a comparator drug. Method: A randomized, evaluator-blinded, three-arm crossover study was conducted in 28 healthy adult subjects to compare the profiles of systemic exposure for epinephrine delivered by MDI versus epinephrine intramuscular (IM) injection and albuterol MDI. Serially sampled plasma epinephrine and albuterol levels were measured and compared between treatment groups. Safety was assessed by adverse events, serial vital signs, electrocardiograms (ECGs), and clinical laboratory tests obtained at each crossover dosing visit. Results: Systemic exogenous drug exposure for inhaled epinephrine MDI (39 pg/mL × hour) was ∼9 times lower than that of epinephrine IM (435 pg/mL × hour) and 122 times lower than that of albuterol MDI (3453 pg/mL × hour) after dose normalization. The Cmax in epinephrine MDI (345 pg/mL) was approximately half of that of epinephrine IM (816 pg/mL) and that of albuterol MDI (681 pg/mL). Plasma drug concentrations for epinephrine MDI dropped rapidly to baseline (∼0.6 hour), while epinephrine IM took ∼8 hours, and albuterol MDI required more than 24 hours. Epinephrine MDI and albuterol MDI resulted in minimal, clinically insignificant changes in vital signs and ECGs, whereas epinephrine IM led to mild transient increases in systolic blood pressure, heart rate, and corrected QT interval. Conclusion: Epinephrine MDI (Primatene MIST) had ∼9 times lower systemic drug exposure (SDE) than that of epinephrine IM and ∼122 times lower than that of albuterol MDI. The lower SDE of inhaled epinephrine also correlated with reassuring safety findings, with no significant cardiovascular adverse effects found, compared with transient effects seen after IM epinephrine. Clinical trial registration number: NCT04207840.