1.Bursts beneath the surface: Using the electrocardiogram as a blueprint to arrhythmogenesis.
Jose Donato A. MAGNO ; Michael Joseph F. AGBAYANI ; Jerome Joseph T. GALEON ; Amraphel L. NICOLAS ; Peter Carlo M. NIERRAS
Philippine Journal of Cardiology 2026;54(S1):82-84
The surface electrocardiogram (ECG) can provide many clues to a patient’s underlying medical condition or tendency for arrhythmogenesis. An 80-year-old man with severe aortic stenosis and an implantable cardioverter-defibrillator (ICD) for advanced heart block presented with burping, chest discomfort and intermittent pounding sensations. His ECG showed atrial fibrillation with intermittent ventricular pacing at 60 bpm characterized by irregularly irregular rhythm, absent P waves, narrow intrinsic QRS complexes alternating with wide-paced beats (left bundle branch block [LBBB] morphology, superior axis) and visible pacing spikes. Device interrogation revealed ventricular tachycardia (VT) storm with multiple appropriate ICD shocks explaining his pounding sensations. This report highlights two key teaching points: recognizing atrial fibrillation during ventricular pacing—a frequently missed diagnosis affecting nearly half of patients with pacemakers—and managing VT storm to reduce shock burden. After device reprogramming and antiarrhythmic adjustment, the patient became asymptomatic.
Human ; Male ; Aged: 65-79 Yrs Old ; Thorax ; Teaching ; Tachycardia, Ventricular ; Electrocardiography ; Atrial Fibrillation ; Bundle-branch Block ; Constriction, Pathologic
2.Left atrial sarcoma with pulmonary embolism: A case report.
Philippine Journal of Surgical Specialties 2025;80(2):65-65
Cardiac myxomas are primary cardiac tumors that presents with symptoms of hemodynamic derangement from obstruction of flow within the cardiac chambers or deformation of a cardiac valve and symptoms associated with embolization.
In this case report, we are presented with a 45-year-old female, diabetic with paroxysmal atrial fibrillation, fair functional capacity, ambulatory, with chief complaint of dyspnea. Admitted as a case of Left atrial myxoma with Pulmonary embolism (proximal right lower lobe, distal left main pulmonary artery division, and superior segmental division of the left lower lobe).
Left atrial myxoma was the first diagnostic consideration, followed by other primary cardiac tumors, and thrombus. Patient was then prepared for surgery and underwent excision of LA myxoma with CardioCel Bioscaffold patch on the inter-atrial septum, mitral ring annuloplasty with plication of the A2-A3 segment, thrombectomy of right inferior pulmonary vein, utilizing cardiopulmonary bypass. Upon pathological examination, the mass was found to be sarcoma with noted myxoid features. The objective of this report is to describe a case of this rare disease entity, and to discuss its presentation, pathological findings and management.
Human ; Female ; Middle Aged: 45-64 Yrs Old ; Pulmonary Embolism ; Pulmonary Artery ; Pulmonary Veins ; Atrial Fibrillation ; Atrial Septum ; Cardiopulmonary Bypass ; Hemodynamics ; Thrombectomy
3.Simulation Study of Myocardial Tissue Ablation Effects Using Flower Petal-Structured Electrodes in Pulsed Ablation.
Chinese Journal of Medical Instrumentation 2025;49(2):125-133
This study aims to evaluate the application of flower petal-structured electrodes in pulsed field ablation (PFA) technology, with a particular focus on their performance in myocardial tissue ablation. Through a combination of simulation techniques and in vitro experiments, the study investigates the effects of different voltage levels, electrode-to-tissue contact distances, and their impact on ablation depth, continuity, and transmurality. The research methods include the construction of a myocardial tissue simulation model, electric field distribution simulation using COMSOL Multiphysics, and in vitro ablation experiments on potato tissue. The results indicate that as voltage increases, the ablation depth significantly increases. At a voltage of 2500 V, a transmural ablation depth of 4 mm can be achieved, and the ablation area remains relatively continuous. The in vitro experiments confirm the consistency of the simulation results, and pulsed field ablation does not induce significant temperature rise, confirming its non-thermal characteristic. The conclusion suggests that PFA technology requires less electrode contact and offers higher ablation efficiency, providing a new technological pathway for the clinical treatment of atrial fibrillation and effectively reducing the risk of complications associated with traditional ablation techniques.
Electrodes
;
Catheter Ablation/instrumentation*
;
Computer Simulation
;
Flowers
;
Atrial Fibrillation/surgery*
;
Myocardium
4.Research Progress of Vagal Nerve Regulation Mechanism in Acupuncture Treatment of Atrial Fibrillation.
Lu-Lu CAO ; Hui-Rong LIU ; Ya-Jie JI ; Yin-Tao ZHANG ; Bing-Quan WANG ; Xiao-Hong XUE ; Pei WANG ; Zhi-Hui LUO ; Huan-Gan WU
Chinese journal of integrative medicine 2025;31(3):281-288
Atrial fibrillation (AF) is the most common arrhythmia in clinical practice. It has a high prevalence and poor prognosis. The application of antiarrhythmic drugs and even surgery cannot completely treat the disease, and there are many sequelae. AF can be classified into the category of "palpitation" in Chinese medicine according to its symptoms. Acupuncture has a significant effect on AF. The authors find that an important mechanism of acupuncture in AF treatment is to regulate the cardiac vagus nerve. Therefore, this article intends to review the distribution and function of vagus nerve in the heart, the application and the regulatroy effect for the treatment of AF.
Atrial Fibrillation/physiopathology*
;
Humans
;
Acupuncture Therapy
;
Vagus Nerve/physiology*
;
Animals
5.An atrial fibrillation prediction model based on quantitative features of electrocardiogram during sinus rhythm in the Chinese population.
Xiaoqing ZHU ; Yajun SHI ; Juan SHEN ; Qingsong WANG ; Tingting SONG ; Jiancheng XIU ; Tao CHEN ; Jun GUO
Journal of Southern Medical University 2025;45(2):223-228
OBJECTIVES:
To develop an early atrial fibrillation (AF) risk prediction model based on large-scale electrocardiogram (ECG) data from the Chinese population.
METHODS:
The data of multiple ECG records of 30 383 patients admitted in the Chinese PLA General Hospital between 2009 and 2023 were randomly divided into the training set and the internal testing set in a 7:3 ratio. The predictive factors were selected based on the training set using univariate analysis, LASSO regression, and the Boruta algorithm. Cox proportional hazards regression was used to establish the ECG model and the composite model incorporating age, gender, and ECG model score. The discrimination power, calibration, and clinical net benefits of the models were evaluated using the area under the receiver operating characteristic curve (AUROC), calibration curves, and decision curves.
RESULTS:
The cohort included 51.1% male patients with a median age of the patients of 51 (36, 62) years and an AF incidence of 4.5% (1370/30 383). In the ECG model, the parameters related to the P wave and QRS complex were identified as significant predictors. In the testing set, the AUROC of the ECG model for predicting 5-year AF risk was 0.77 (95% CI: 0.74-0.80), which was increased to 0.81 (95% CI: 0.78-0.83) after incorporating age and gender, with a net reclassification improvement of 0.123 and an integrated discrimination improvement of 0.04 (P<0.05). The calibration curve of the model was close to the diagonal line. Decision curve analysis showed that the clinical net benefit of the composite model was higher than that of the ECG model across the majority of threshold probability.
CONCLUSIONS
The composite model incorporating quantitative ECG features during sinus rhythm, along with age and gender, can effectively predict AF risk in the Chinese population, thus providing a low-cost screening tool for early AF risk assessment and management.
Humans
;
Atrial Fibrillation/epidemiology*
;
Electrocardiography
;
Middle Aged
;
Male
;
Female
;
China/epidemiology*
;
Proportional Hazards Models
;
Adult
;
Risk Factors
;
Risk Assessment
;
East Asian People
6.A lightweight classification network for single-lead atrial fibrillation based on depthwise separable convolution and attention mechanism.
Yong HONG ; Xin ZHANG ; Mingjun LIN ; Qiucen WU ; Chaomin CHEN
Journal of Southern Medical University 2025;45(3):650-660
OBJECTIVES:
To design a deep learning model that balances model complexity and performance to enable its integration into wearable ECG monitoring devices for automated diagnosis of atrial fibrillation.
METHODS:
This study was performed based on data from 84 patients with atrial fibrillation, 25 patients with atrial fibrillation, and 18 subjects without obvious arrhythmia collected from the publicly available datasets LTAFDB, AFDB, and NSRDB, respectively. A lightweight attention network based on depthwise separable convolution and fusion of channel-spatial information, namely DSC-AttNet, was proposed. Depthwise separable convolution was introduced to replace standard convolution and reduce model parameters and computational complexity to realize high efficiency and light weight of the model. The multilayer hybrid attention mechanism was embedded to compute the attentional weights of the channels and spatial information at different scales to improve the feature expression ability of the model. Ten-fold cross-validation was performed on LTAFDB, and external independent testing was conducted on AFDB and NSRDB datasets.
RESULTS:
DSC-AttNet achieved a ten-fold average accuracy of 97.33% and a precision of 97.30% on the test set, both of which outperformed the other 4 comparison models as well as the 3 classical models. The accuracy of the model on the external test set reached 92.78%, better than those of the 3 classical models. The number of parameters of DSC-AttNet was 1.01M, and the computational volume was 27.19G, both smaller than the 3 classical models.
CONCLUSIONS
This proposed method has a smaller complexity, achieves better classification performance, and has a better generalization ability for atrial fibrillation classification.
Atrial Fibrillation/diagnosis*
;
Humans
;
Electrocardiography
;
Deep Learning
;
Wearable Electronic Devices
;
Neural Networks, Computer
7.Epidemiology of atrial fibrillation/atrial flutter and its risk factors from 1990 to 2021: a systematic analysis and Mendelian randomization study based on the China and Global Burden of Disease Study 2021.
Huihua MA ; Kuipo YAN ; Gang LIU ; Yazhou XU ; Lei ZHANG ; Yizhuo LI
Journal of Southern Medical University 2025;45(10):2182-2190
OBJECTIVES:
To analyze the changes in disease burden and risk factors of atrial fibrillation/atrial flutter (AF/AFL) in China and globally from 1990 to 2021 to provide epidemiological evidence for developing effective preventive measures for AF/AFL in China.
METHODS:
Based on data from the Global Burden of Disease Study 2021, we analyzed sex- and age-specific AF/AFL burden metrics across 204 countries or territories. Age-standardized incidence rate (ASIR), prevalence, mortality rate (ASMR), and disability-adjusted life-years (DALYs) rate (ASDR) were calculated. Joinpoint regression was employed to compute average annual percentage changes (AAPC) in trends. The risk factors were systematically evaluated and further validated using Mendelian randomization analysis.
RESULTS:
From 1990 to 2021, China experienced an increase in ASIR of AF/AFL (from 42.63 to 44.93 per 100 000), contrasting with the global decline. While China's ASMR decreased (from 4.93 to 4.33 per 100 000), global ASMR rose slightly (from 4.24 to 4.36 per 100 000). China's ASDR remained stable at 93.29 per 100 000, whereas global ASDR increased marginally (100.81 to 101.40 per 100 000). Significant sex disparities were observed: males showed higher ASIR and ASDR, while females exhibited greater ASMR and ASDR. China had higher incidence and prevalence but lower mortality and DALY rates compared to global averages. In 2021, the key risk factors for AF/AFL included elevated systolic blood pressure, high BMI, smoking, alcohol use, high-sodium diet, and low temperature. Gender-specific patterns emerged: smoking was predominant in males, whereas high BMI disproportionately affected females.
CONCLUSIONS
AF/AFL incidence and prevalence keep increasing in China, and its large population base and demographic aging pose significant public health challenges. Maintaining healthy lifestyle habits, including smoking cessation, alcohol moderation, and a low-sodium diet can help to lower AF/AFL incidence, and regular screenings is crucial for its early detection and treatment.
Humans
;
China/epidemiology*
;
Risk Factors
;
Atrial Flutter/epidemiology*
;
Atrial Fibrillation/epidemiology*
;
Mendelian Randomization Analysis
;
Male
;
Female
;
Global Burden of Disease
;
Incidence
;
Prevalence
;
Middle Aged
;
Disability-Adjusted Life Years
;
Aged
8.Acupuncture activates vagus nerve-macrophage axis and improves cardiac electrophysiology and inflammatory response in rats with atrial fibrillation via α7nAChR-JAK2/STAT3 pathway.
Zhi-Han LI ; Wen-Min YANG ; Qi HUANG ; Guang-Xia SHI ; Cun-Zhi LIU ; Yu-Qin ZHANG
Journal of Integrative Medicine 2025;23(4):398-414
OBJECTIVE:
The occurrence and development of atrial fibrillation (AF) are influenced by the autonomic nervous system and inflammation. Acupuncture is an effective treatment for AF. This study explored the protective effects of acupuncture in a rat model of paroxysmal AF and investigated its mechanisms.
METHODS:
Male Sprague-Dawley rats (n = 130) were randomly divided into blank control (Con), sham operation (Sham), AF, and acupuncture treatment (Acu) groups. A paroxysmal AF model was established by rapid atrial pacing through the jugular vein. Rats in the Acu group were immobilized to receive acupuncture treatment at Neiguan acupoint (PC6) for 20 min daily for seven days. The other groups were immobilized for the same duration over the treatment period but did not receive acupuncture. The AF induction rate, AF duration, cardiac electrophysiological parameters, and heart rate variability were evaluated by monitoring surface electrocardiogram and vagus nerve discharge signals. After the intervention, the rats were euthanized, and atrial morphology was assessed using haematoxylin and eosin staining. The expression of macrophage F4/80 antigen (F4/80) and cluster of differentiation (CD) 86 in atrial myocardial tissue was detected using immunohistochemistry, immunofluorescence and flow cytometry. The expression levels or contents of interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), α7 nicotinic acetylcholine receptor (α7nAChR), phosphorylated Janus kinase 2 (p-JAK2), and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in atrial myocardial tissue were detected using Western blotting, reverse transcription-quantitative polymerase chain reaction, or enzyme-linked immunosorbent assay. The role of α7nAChR in acupuncture treatment was verified by intraperitoneal injection of the α7nAChR antagonist methyllycaconitine (MLA).
RESULTS:
Compared with the AF group, acupuncture significantly reduced AF duration and induction rate, improved cardiac electrophysiology by enhancing vagus nerve activity and regulating autonomic balance. It also decreased the pro-inflammatory M1 macrophage proportion, alleviating myocardial injury and infiltration. MLA weakened acupuncture's electrophysiological improvement and anti-inflammatory effect. Results suggest that acupuncture triggers the α7nAChR-JAK2/STAT3 pathway and exerts cardioprotection via neuroimmune regulation.
CONCLUSION
Acupuncture significantly reduced the AF induction rate, shortened AF duration, improved cardiac electrophysiological parameters, enhanced vagus nerve activity, and decreased the expression of pro-inflammatory M1 macrophages and inflammatory factors in rats with paroxysmal AF. Its positive effects are related to the activation of the α7nAChR-mediated JAK2/STAT3 signalling pathway, indicating that the interaction between cardiac vagus nerve and macrophages may be a potential target for acupuncture in the prevention and treatment of AF. Please cite this article as: Li ZH, Yang WM, Huang Q, Shi GX, Liu CZ, Zhang YQ. Acupuncture activates vagus nerve-macrophage axis and improves cardiac electrophysiology and inflammatory response in rats with atrial fibrillation via α7nAChR-JAK2/STAT3 pathway. J Integr Med. 2025; 23(4): 398-414.
Animals
;
Male
;
Rats, Sprague-Dawley
;
STAT3 Transcription Factor/metabolism*
;
alpha7 Nicotinic Acetylcholine Receptor/metabolism*
;
Janus Kinase 2/metabolism*
;
Atrial Fibrillation/metabolism*
;
Vagus Nerve/physiopathology*
;
Rats
;
Acupuncture Therapy
;
Signal Transduction
;
Macrophages/metabolism*
;
Inflammation/therapy*
9.Technical standards for performing radiofrequency catheter ablation for atrial fibrillation: a series of consortium standards.
Chinese Journal of Internal Medicine 2025;64(1):23-35
Atrial fibrillation (AF) has emerged as a major global cardiovascular disease in the 21st century. In China, there are greater than 12 million patients with AF, and its incidence continues to rise. AF affects patients' quality of life and significantly increases the risks of mortality, stroke, heart failure, cognitive impairment, and dementia. In recent years, multiple clinical guidelines have expanded the indications for catheter ablation and raised its level of recommendation. Concurrently, there has been a rapid and sustained increase in the number of AF ablation procedures performed across China. Among these, radiofrequency catheter ablation remains the most used method. Consequently, the Chinese Heart Rhythm Society of the Chinese Society of Biomedical Engineering, in collaboration with 40 arrhythmia centers and 60 leading clinical experts specializing in AF catheter ablation, developed a comprehensive set of standards. These standards were developed based on extensive clinical experience accumulated in recent years and the latest national and international AF guidelines and consensus documents. They address five critical domains: periprocedural management, intra-atrial septal puncture, anatomical reconstruction and electroanatomic mapping, ablation, and complication identification and management. By providing a structured framework, these standards aim to guide AF catheter ablation practice, thereby enhancing procedural safety and efficacy.
Humans
;
Catheter Ablation/standards*
;
Atrial Fibrillation/surgery*
;
China
10.Obstructive sleep apnoea and nocturnal atrial fibrillation in patients with ischaemic heart disease.
Silin KUANG ; Yiong Huak CHAN ; Serene WONG ; See Meng KHOO
Singapore medical journal 2025;66(4):190-194
INTRODUCTION:
Arrhythmias, especially atrial fibrillation (AF) and ventricular arrhythmias, are independent risk factors of mortality in patients with ischaemic heart disease (IHD). While there is a growing body of evidence that suggests an association between obstructive sleep apnoea (OSA) and cardiac arrhythmias, evidence on this relationship in patients with IHD has been scant and inconsistent. We hypothesised that in patients with IHD, severe OSA is associated with an increased risk of nocturnal arrhythmias.
METHODS:
We studied 103 consecutive patients with IHD who underwent an overnight polysomnography. Exposed subjects were defined as patients who had an apnoea-hypopnoea index (AHI) ≥30/h (severe OSA), and nonexposed subjects were defined as patients who had an AHI <30/h (nonsevere OSA). All electrocardiograms (ECGs) were interpreted by the Somte ECG analysis software and confirmed by a physician blinded to the presence or absence of exposure. Arrhythmias were categorised as supraventricular and ventricular. Arrhythmia subtypes (ventricular, atrial and conduction delay) were analysed as dichotomous outcomes using multiple logistic regression models.
RESULTS:
Atrial fibrillation and AF/flutter (odds ratio 13.5, 95% confidence interval 1.66-109.83; P = 0.003) were found to be more common in the severe OSA group than in the nonsevere OSA group. This association remained significant after adjustment for potential confounders. There was no significant difference in the prevalence of ventricular and conduction delay arrhythmias between the two groups.
CONCLUSION
In patients with IHD, there was a significant association between severe OSA and nocturnal AF/flutter. This underscores the need to evaluate for OSA in patients with IHD, as it may have important implications on clinical outcomes.
Humans
;
Sleep Apnea, Obstructive/diagnosis*
;
Atrial Fibrillation/diagnosis*
;
Male
;
Female
;
Middle Aged
;
Polysomnography
;
Electrocardiography
;
Myocardial Ischemia/complications*
;
Aged
;
Risk Factors
;
Logistic Models


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