BACKGROUND: Papillary muscle (PM) infarction (PMI) detected by cardiac magnetic resonance imaging (CMR) is associated with poor outcomes. Whether PM parameters provide more value for mitral regurgitation (MR) management currently remains unclear. Therefore, we examined the prognostic value of PMI using CMR in patients with MR.
METHODS: Between March 2018 and July 2023, we retrospectively enrolled 397 patients with MR undergoing CMR. CMR was used to detect PMI qualitatively and quantitively. We also collected baseline clinical, echocardiography, and follow-up data.
RESULTS: Of the 397 patients with MR (52.4 ± 13.9 years), 117 (29.5%) were assigned to the PMI group, with 280 (70.5%) in the non-PMI group. PMI was demonstrated more in the posteromedial PM (PM-PM, 98/117) than in the anterolateral PM (AL-PM, 45/117). Compared with patients without PMI, patients with PMI had a decreased AL-PM (41.5 ± 5.4 vs. 45.6 ± 5.3)/PM-PM diastolic length (35.0 ± 5.2 vs. 37.9 ± 4.0), PM-longitudinal strain (LS, 20.4 ± 6.1 vs. 24.9 ± 4.6), AL-PM-LS (19.7 ± 6.8 vs. 24.7 ± 5.6)/PM-PM-LS (21.2 ± 7.9 vs. 25.2 ± 6.0), and increased inter-PM distance (25.7 ± 8.0 vs. 22.7 ± 6.2, all p < 0.001). Multiple logistic regression analyses identified male sex (odds ratio [OR] = 3.65, 95% confidence interval = 1.881-7.081, p < 0.001) diabetes mellitus (OR/95% CI/p = 2.534/1.13-5.68/0.024), AL-PM diastolic length (OR/95% CI/p = 0.841/0.77-0.92/< 0.001), PM-PM diastolic length (OR/95% CI/p = 0.873/0.79-0.964/0.007), inter-PM distance (OR/95% CI/p = 1.087/1.028-1.15/0.003), AL-PM-LS (OR/95% CI/p = 0.892/0.843-0.94/< 0.001), and PM-PM-LS (OR/95% CI/p = 0.95/0.9-0.992/0.021) as independently associated with PMI. Over a 769 ± 367-day follow-up, 100 (25.2%) patients had arrhythmia. Cox regression analyses indicated that PMI (hazard ratio [HR]/95% CI/p = 1.644/1.062-2.547/0.026), AL-PM-LS (HR/95% CI/p = 0.937/0.903-0.973/0.001), and PM-PM-LS (HR/95% CI/p = 0.933/0.902-0.965/< 0.001) remained independently associated with MR.
CONCLUSIONS: The CMR-derived PMI and LS parameters improve the evaluation of PM dysfunction, indicating a high risk for arrhythmia, and provide additive risk stratification for patients with MR.

UNASSIGNED: To explore the effect and safety of calcium dibutyryl adenosine cyclophosphate (dbcAMP-Ca) combined with metoprolol in the treatment of older adults with heart failure combined with arrhythmia.
UNASSIGNED: A total of 102 elderly patients with heart failure combined with arrhythmia were enrolled in our hospital between February 2021 and April 2023. The list of patients enrolled was entered into a random database by independent staffs not involved in the study and random assignment sequences were generated by the SAS9.4 software. Then, the 102 elderly patients were divided into a control group ( n=51) and an experimental group ( n=51). Patients in the control group were given metoprolol at an initial dose of 6.25 mg/d, which was gradually increased to the target dose of 25 mg/d. Patients in the experimental group were given 40 mg of dbcAMP-Ca once a day via intravenous drip in addition to the treatment given to the control group. Both groups were treated for 4 weeks. The rate of effective response to clinical treatment (the number of cases achieving significant effects and those achieving some effects divided by the total number of cases in the group) was defined as the main outcome index. Secondary indexes included cardiac function, heart rate variability, exercise ability, hemorheology, myocardial injury indexes, inflammatory indexes, and the occurrence of adverse reactions.
UNASSIGNED: The rate of effective response to clinical treatment was higher in the experimental group than that in the control group (94.12% [48/51] vs. 78.43% [40/51], P<0.05). After treatment, the left ventricular end-diastolic and end-systolic dimensions (LVEDD and LVESD) and the interventricular septal thickness (IVS) were lower in the experimental group than those in the control group, while the left ventricular ejection fraction (LVEF) and the stroke volume (SV) were higher in the experimental group than those in the control group ( P<0.05). In terms of heart rate variability after treatment, the standard deviation of all the normal-to-normal intervals/the average of all the normal-to-normal intervals (SDNN/SDANN), the percentage of NN50 in the total number of normal-to-normal intervals (PNN50%), and the root mean square of the differences between adjacent normal-to-normal intervals/root mean square differences of successive R-R intervals (RMSSD) were higher in the experimental group than those in the control group ( P<0.05). In terms of exercise capacity after treatment, the subjects in the experimental group covered more distance in the 6-min walk test than those in the control group did ( P<0.05). In terms of the hemorheology indexes after treatment, the levels of platelet aggregation rate (PAgT), fibrinogen (FIB), erythrocyte sedimentation rate (ESR), and whole blood viscosity (ηb) were lower in the experimental group than those in the control group ( P<0.05). In terms of the myocardial injury indexes after treatment, the levels of serum N-terminal pro-brain natriuretic peptide (NT-pro BNP) and cardiac troponin I (cTnI) were lower in the experimental group than those in the control group, while the levels of insulin-like growth factor 1 (IGF-1) and cardiotrophin 1 (CT-1) were higher in the experimental group than those in the control group ( P<0.05). In terms of the inflammatory indexes after treatment, the levels of interleukin-6 (IL-6), high-sensitive C-reactive protein (hs-CRP), and tumor necrosis factor-α (TNF-α) were lower in the experimental group than those in the control group ( P<0.05). The incidence of adverse reactions in the experimental group (9.80%) and that in the control group (7.84%) were comparable ( P>0.05).
UNASSIGNED: The use of dbcAMP-Ca in addition to metoprolol can effectively improve cardiac function, heart rate variability, and exercise tolerance, while inhibiting inflammatory response in elderly patients with heart failure combined with arrhythmia, with high medication safety. The combination medication shows better safety and therapeutic effects than those of metoprolol used alone.

Antiphospholipid syndrome (APS) is a systemic autoimmune syndrome characterized by arterial or venous thrombosis, pregnancy complications and thrombocytopenia. The aim of this study is to investigate the association between APS and atrial fibrillation (AF) among patients in Peking University People\'s Hospital. A single center retrospective study was conducted. Cases were hospitalized patients diagnosed with AF by a cardiologist while the control group patients did not exhibit cardiac diseases. The results of the study revealed that in multivariable logistic regression, APS, anticardiolipin antibody (aCL) positivity and anti-beta-2-glycoprotein antibody (anti-β2GPI) positivity are independent risk factors of AF. APS, aCL positivity and anti-β 2GPI positivity are statistically different between AF patients and non-AF patients. Forthcoming studies are needed to clarify the potential link between APS and AF.

The global incidence and prevalence of arrhythmias are continuously increasing. However, the precise mechanisms of underlying arrhythmogenesis and the optimal measures for effective treatment remain incompletely understood. The inducible form of heme oxygenase, known as heme oxygenase-1 (HO-1), is recognized as a potent antioxidant molecule capable of exerting anti-inflammatory and anti-apoptotic effects. Recent research indicates that HO-1 plays a role in preventing arrhythmias by mitigating cardiac remodeling, including electrical remodeling, ion remodeling, and structural remodeling. This review aimed to consolidate current knowledge regarding the involvement of HO-1 in arrhythmias and elucidate its underlying mechanisms of action.

OBJECTIVE: This study aims to address the challenges of imbalanced heartbeat classification using electrocardiogram (ECG). In this proposed novel deep-learning method, the focus is on accurately identifying minority classes in conditions characterized by significant imbalances in ECG data. Approach: We propose a Feature Fusion Neural Network enhanced by a Dynamic Minority-Biased Batch Weighting Loss Function. This network comprises three specialized branches: the Complete ECG Data Branch for a comprehensive view of ECG signals, the Local QRS Wave Branch for detailed features of the QRS complex, and the R Wave Information Branch to analyze R wave characteristics. This structure is designed to extract diverse aspects of ECG data. The dynamic loss function prioritizes minority classes while maintaining the recognition of majority classes, adjusting the network\'s learning focus without altering the original data distribution. Together, this fusion structure and adaptive loss function significantly improve the network\'s ability to distinguish between various heartbeat classes, enhancing the accuracy of minority class identification. Main Results: The proposed method demonstrated balanced performance within the MIT-BIH dataset, especially for minority classes. Under the intra-patient paradigm, the accuracy, sensitivity, specificity, and positive predictive value (PPV) for Supraventricular ectopic beat were 99.63%, 93.62%, 99.81%, and 92.98%, respectively, and for Fusion beat were 99.76%, 85.56%, 99.87%, and 84.16%, respectively. Under the inter-patient paradigm, these metrics were 96.56%, 89.16%, 96.84%, and 51.99% for Supraventricular ectopic beat, and 96.10%, 77.06%, 96.25%, and 13.92% for Fusion beat, respectively. Significance: This method effectively addresses the class imbalance in ECG datasets. By leveraging diverse ECG signal information and a novel loss function, this approach offers a promising tool for aiding in the diagnosis and treatment of cardiac conditions. .

BACKGROUND: The accurate diagnosis and effective management of arrhythmias are crucial, with nurses playing a key role in the early detection and treatment, significantly impacting patient outcomes. Improving education on arrhythmias among nurses, especially in critical care and perioperative settings, can enhance patient safety and the quality of care.
METHODS: A total of 116 trainee nurses were randomly divided into two groups: one utilizing the conceive-design-implement-operate (CDIO) model and the other employing a traditional lecture-based learning (LBL) method, to undergo arrhythmia training. The studyassessed the effects of the two teaching methods and investigated the students\' attitudes toward these educational practices, with all participants completing pre- and post-course tests.
RESULTS: The CDIO model significantly enhances nursing students\' arrhythmia proficiency, yielding higher test scores and sustained improvement after 24-week compared to the traditional LBL method, alongside markedly better self-learning enthusiasm, understanding, satisfaction with the teaching approach and effectiveness, and interest in learning arrhythmia. The CDIO model in nursing arrhythmia courses boosts theoretical knowledge and application, showing potential in clinical skill enhancement.
CONCLUSIONS: Our study introduces the CDIO model in nursing arrhythmia courses, with improvement in knowledge and skills, and promise for broader application.

UNASSIGNED: Arrhythmia is an important indication of underlying cardiovascular diseases (CVD) and is prevalent worldwide. Accurate diagnosis of arrhythmia is crucial for timely and effective treatment. Electrocardiogram (ECG) plays a key role in the diagnosis of arrhythmia. With the continuous development of deep learning and machine learning processes in the clinical field, ECG processing algorithms have significantly advanced the field with timely and accurate diagnosis of arrhythmia.
UNASSIGNED: In this study, we combined the wavelet time-frequency maps with the novel Swin Transformer deep learning model for the automatic detection of cardiac arrhythmias. In specific practice, we used the MIT-BIH arrhythmia dataset, and to improve the signal quality, we removed the high-frequency noise, artifacts, electromyographic noise and respiratory motion effects in the ECG signals by the wavelet thresholding method; we used the complex Morlet wavelet for the feature extraction, and plotted wavelet time-frequency maps to visualise the time-frequency information of the ECG; we introduced the Swin Transformer model for classification and achieve high classification accuracy of ECG signals through hierarchical construction and self attention mechanism, and combines windowed multi-head self-attention (W-MSA) and shifted window-based multi-head self-attention (SW-MSA) to comprehensively utilise the local and global information.
UNASSIGNED: To enhance the confidence of the experimental results, we evaluated the performance using intra-patient and inter-patient paradigm analyses, and the model classification accuracies reached 99.34% and 98.37%, respectively, which are better than the currently available detection methods.
UNASSIGNED: The results reveal that our proposed method is superior to currently available methods for detecting arrhythmia ECG. This provides a new idea for ECG based arrhythmia diagnosis.

Cardio-oncology is a new field of interest in cardiology focusing on the detection and treatment of cardiovascular diseases, such as arrhythmias, myocarditis, and heart failure, as side-effects of chemotherapy and radiotherapy. The association between chemotherapeutic agents and arrhythmias has previously been established. Atrial tachyarrhythmias, particularly atrial fibrillation, are most common, but ventricular arrhythmias, including those related to treatment-induced QT prolongation, and bradyarrhythmias can also occur. However, the association between chemotherapeutic agents and atrioventricular re-entrant tachycardia (AVRT)/atrioventricular node re-entrant tachycardia (AVNRT) remains poorly understood. Here, we report a patient with new-onset AVRT/AVNRT and lung cancer who underwent chemotherapy. We considered that chemotherapy or cancer itself may have been a trigger for the initiation of paroxysmal AVRT/AVNRT, and that radiofrequency catheter ablation was effective in treating this type of tachycardia. Here, possible mechanisms and potential genes (mostly ion channels) involved in AVRT/AVNRT are summarized and the mechanisms underlying the possible regulatory patterns of cancer cells and chemotherapy on ion channels are reviewed. Finally, we considered that ion channel abnormalities may link cancer or chemotherapy to the onset of AVRT/AVNRT. The aim of the present study was to highlight the association between chemotherapeutic agents and AVRT/AVNRT and to provide new insights for future research. Understanding the intermediate mechanisms between chemotherapeutic agents and AVRT/AVNRT may be beneficial in preventing chemotherapy-evoked AVRT/AVNRT (and/or other arrhythmias) in future.

Sympathetic hyperinnervation is the leading cause of fatal ventricular arrhythmia (VA) following myocardial infarction (MI). Cardiac mast cells cause arrhythmias directly through degranulation. However, the role and mechanism of mast cell degranulation in sympathetic remodeling remain unknown. We investigated the role of oxytocin (OT) in stabilizing cardiac mast cells and improving sympathetic innervation in rats. MI was induced by coronary artery ligation. Western blotting, immunofluorescence, and toluidine staining of mast cells were performed to determine the expression and location of target protein. Mast cells accumulated significantly in peri-infarcted tissues and were present in a degranulated state. They expressed OT receptor (OTR), and OT infusion reduced the number of degranulated cardiac mast cells post-MI. Sympathetic hyperinnervation was attenuated as assessed by immunofluorescence for tyrosine hydroxylase (TH). Seven days post MI, the arrhythmia score of programmed electrical stimulation was higher in vehicle-treated rats with MI than in rats treated with OT. An in vitro study showed that OT stabilized mast cells via the PI3K/AKT signaling pathway. Further in vivo studies on OTR-deficient mice showed worsening mast cell degranulation and worsening sympathetic innervation. OT pretreatment inhibited cardiac mast cell degranulation post MI and prevented sympathetic hyperinnervation, along with mast cell stabilization via the PI3K/AKT pathway.Significance Statement 1.We confirmed the role and mechanism of oxytocin (OT) in stabilizing cardiac mast cells. 2. It is the first study to elucidate the mechanism of oxytocin (OT)-mediated sympathetic hyperinnervation post-myocardial infarction (MI).

BACKGROUND: COVID-19 is a new infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS CoV-2). Since the outbreak in December 2019, it has caused an unprecedented world pandemic, leading to a global human health crisis. Although SARS CoV-2 mainly affects the lungs, causing interstitial pneumonia and severe acute respiratory distress syndrome, a number of patients often have extensive clinical manifestations, such as gastrointestinal symptoms, cardiovascular damage and renal dysfunction.
OBJECTIVE: This review article discusses the pathogenic mechanisms of cardiovascular damage in COVID-19 patients and provides some useful suggestions for future clinical diagnosis, treatment and prevention.
METHODS: An English-language literature search was conducted in PubMed and Web of Science databases up to 12th April, 2024 for the terms \"COVID-19\", \"SARS CoV-2\", \"cardiovascular damage\", \"myocardial injury\", \"myocarditis\", \"hypertension\", \"arrhythmia\", \"heart failure\" and \"coronary heart disease\", especially update articles in 2023 and 2024. Salient medical literatures regarding the cardiovascular damage of COVID-19 were selected, extracted and synthesized.
RESULTS: The most common cardiovascular damage was myocarditis and pericarditis, hypertension, arrhythmia, myocardial injury and heart failure, coronary heart disease, stress cardiomyopathy, ischemic stroke, blood coagulation abnormalities, and dyslipidemia. Two important pathogenic mechanisms of the cardiovascular damage may be direct viral cytotoxicity as well as indirect hyperimmune responses of the body to SARS CoV-2 infection.
CONCLUSIONS: Cardiovascular damage in COVID-19 patients is common and portends a worse prognosis. Although the underlying pathophysiological mechanisms of cardiovascular damage related to COVID-19 are not completely clear, two important pathogenic mechanisms of cardiovascular damage may be the direct damage of the SARSCoV-2 infection and the indirect hyperimmune responses.