Associations of Atrial Fibrillation After Noncardiac Surgery With Stroke, Subsequent Arrhythmia, and Death : A Cohort Study

Epidemiology, risk factors and mechanism of breast cancer and atrial fibrillation

Cancer and cardiovascular diseases are leading causes of death worldwide. Among them, breast cancer is one of the most common malignancies in women, while atrial fibrillation is one of the most extensively studied arrhythmias, with significant public health implications. As the global population ages and advancements in cancer treatments continue, the survival rates of breast cancer patients have significantly improved, leading to an increasing coexistence of breast cancer and atrial fibrillation. However, the mechanisms underlying this coexistence remain insufficiently studied, and there is no consensus on the optimal treatment strategies for these patients. This review consolidates existing research to systematically explore the epidemiological characteristics, risk factors, and pathophysiological mechanisms of both breast cancer and atrial fibrillation. It focuses on the unique signaling pathways associated with different molecular subtypes of breast cancer and their potential impact on the mechanisms of atrial fibrillation. Additionally, the relationship between atrial fibrillation treatment medications and breast cancer is discussed. These insights not only provide essential evidence for the precise prevention and management of atrial fibrillation in breast cancer patients but also lay a solid theoretical foundation for interdisciplinary clinical management practices.

Anticoagulation at the end of life: whether, when, and how to treat

Nearly 2 out of 3 patients with venous thromboembolism (VTE) and 1 out of 4 patients with atrial fibrillation (AF) will die within the year. Whether, when, and how to manage anticoagulation at the end of life requires many trade-offs. Patients and clinicians must balance symptom burden, greatly elevated bleeding and thrombosis risks, competing comorbidities and medications, and changing goals over time. This review uses cases of VTE and AF to present a framework for care that draws upon existing disease-specific data and cutting-edge palliative care science. It reviews strategies for the difficult task of estimating a patient's prognosis, characterizes the enormous public health burden of anticoagulation in serious illness, and analyzes the data on anticoagulation outcomes among those with limited life expectancy. Finally, an approach to individualized decision-making that is predicated on patients' priorities and evidence-based strategies for starting, continuing, or stopping anticoagulation at the end of life are presented.

A novel nomogram prediction model for postoperative atrial fibrillation in patients undergoing laparotomy

BACKGROUND

Postoperative atrial fibrillation (POAF) is an ordinary complication of surgery, particularly cardiac surgery. It significantly increases in-hospital mortality and costs. This study aimed to establish a nomogram prediction model for POAF in patients undergoing laparotomy. The model is expected to identify individuals at a high risk of POAF before surgery in clinical practice.

METHODS

A retrospective observational case-control study involving 230 adult patients (60 patients with POAF, 120 patients in the control group, and 50 patients in the validation group) who underwent laparotomy was retrieved from two hospitals. Independent risk variables for POAF were investigated using logistic regression and the least absolute shrinkage and selection operator (LASSO) regression analysis. Subsequently, a nomogram model for POAF was constructed by multivariate logistic regression equations. The prediction model was internally validated by bootstrap method and externally validated with the validation group data. To assess the discriminative ability of the nomogram model, a receiver operating characteristic (ROC) curve was generated and a calibration curve was employed to assess the concentricity between the model's probability curve and the ideal curve. Subsequently, decision curve analysis (DCA) was performed to assess the clinical effectiveness of the model.

RESULTS

C-reactive protein (CRP), lymphocyte-to-monocyte ratio(LMR), blood urea nitrogen (BUN), and Macruz index were independent risk variables for POAF in patients who underwent laparotomy. A user-friendly and efficient prediction nomogram was visualized using R software. This nomogram exhibited strong discrimination, as evidenced by an area under the ROC curve (AUC) of 0.90 (95% CI 0.8509-0.9488) for the training set, 0.86 (95% CI 0.7142-1) for the test set, and 0.9792 (95% CI 0.9293-1) for the validation group data. The C-index of the bootstrap nomogram model was 0.8998. Furthermore, DCA revealed that this model displayed excellent fit and calibration, as well as positive net benefits.

CONCLUSIONS

A nomogram prediction model was constructed for POAF in patients who underwent abdominal surgery. The nomogram prediction model is expected to identify individuals at high risk of POAF in clinical practice for prophylactic therapeutic intervention prior to surgery.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Perioperative Care of Heart Failure, Arrhythmias, and Valvular Heart Disease

Frequently, the question of whether or not a patient is stable for surgery boils down to the question, "Does this patient need a preoperative stress test?" However, coronary artery disease and ischemic heart disease are only some of the many cardiac conditions that patients present with preoperatively-and that can negatively impact their intraoperative management and postoperative outcomes. This article will explore the evidence based, patient centered best practices surrounding the perioperative evaluation and management of heart failure, arrhythmias, and valvular heart disease.

Role of anticoagulation therapy in modifying stroke risk associated with new-onset atrial fibrillation after non-cardiac surgery

The role of antithrombotic therapy in the prevention of ischemic stroke after non-cardiac surgery is unclear. In this study, we tested the hypothesis that the association of new-onset postoperative atrial fibrillation (POAF) on ischemic stroke can be mitigated by postoperative oral anticoagulation therapy. Of 251,837 adult patients (155,111 female (61.6%) and 96,726 male (38.4%)) who underwent non-cardiac surgical procedures at two sites, POAF was detected in 4,538 (1.8%) patients. The occurrence of POAF was associated with increased 1-year ischemic stroke risk (3.6% versus 2.3%; adjusted risk ratio (RRadj) = 1.60 (95% confidence interval (CI): 1.37-1.87), P < 0.001). In patients with POAF, the risk of developing stroke attributable to POAF was 1.81 (95% CI: 1.44-2.28; P < 0.001) without oral anticoagulation, whereas, in patients treated with anticoagulation, no significant association was observed between POAF and stroke (RRadj = 1.04 (95% CI: 0.71-1.51), P = 0.847, P for interaction = 0.013). Furthermore, we derived and validated a computational model for the prediction of POAF after non-cardiac surgery based on demographics, comorbidities and procedural risk. These findings suggest that POAF is predictable and associated with an increased risk of postoperative ischemic stroke in patients who do not receive postoperative anticoagulation.

Management of atrial fibrillation in older adults

Most people with atrial fibrillation are older adults, in whom atrial fibrillation co-occurs with other chronic conditions, polypharmacy, and geriatric syndromes such as frailty. Yet most randomized controlled trials and expert guidelines use an age agnostic approach. Given the heterogeneity of aging, these data may not be universally applicable across the spectrum of older adults. This review synthesizes the available evidence and applies rigorous principles of aging science. After contextualizing the burden of comorbidities and geriatric syndromes in people with atrial fibrillation, it applies an aging focused approach to the pillars of atrial fibrillation management, describing screening for atrial fibrillation, lifestyle interventions, symptoms and complications, rate and rhythm control, coexisting heart failure, anticoagulation therapy, and left atrial appendage occlusion devices. Throughout, a framework is suggested that prioritizes patients' goals and applies existing evidence to all older adults, whether atrial fibrillation is their sole condition, one among many, or a bystander at the end of life.

Soluble ST2 is associated with postoperative atrial fibrillation after cardiac surgery in postmenopausal women

BACKGROUND

Postoperative atrial fibrillation (POAF) represents the most common complication following cardiac surgery. Approximately one-third of patients experiencing POAF transition to atrial fibrillation within a year, challenging the notion of POAF as merely a transient event. Soluble ST2 (sST2) is an established biomarker regarding fibrosis and myocardial stretch, however, its role in predicting the onset of POAF remains unclear.

METHODS

Preoperative sST2 levels have been assessed in 496 individuals with no prior history of AF who underwent elective cardiac surgery, including valve, coronary artery bypass graft surgery, or a combined procedure.

RESULTS

The average age was 70 years, and 29.4 % were female. Overall, 42.3 % developed POAF. sST2 levels were found to be significantly higher in patients with POAF. Interestingly, sST2 was only predictive of POAF in females with an adjusted OR of 1.894 (95 %CI:1.103-3.253; p = 0.021) and not males (OR:1.091; 95 %CI:0.849-1.402; p = 0.495). Furthermore, within a linear regression model it was observed that for every 1 ng/mL increase in sST2 levels, the average POAF duration extended by 39.5 min (95 %CI:15.8-63.4 min; p = 0.001).

CONCLUSION

sST2 predicts the onset of POAF in women but not men undergoing cardiac surgery. Furthermore, sST2 levels were associated with the subsequent burden of POAF. Thus, assessment of sST2 in addition to clinical risk factors could improve risk stratification for development of POAF following elective cardiac surgery.

Risk Factors and Prognosis of Perioperative Atrial Fibrillation in Elderly Patients Undergoing VATS Lung Surgery: A Retrospective Cohort Study

Background

Atrial fibrillation (AF) has become the most common postoperative arrhythmia of thoracic surgery. This study aimed to investigate the risk factors and complications of perioperative atrial fibrillation (PoAF) in elderly patients who underwent video-assisted thoracoscopic surgery (VATS).

Methods

Data were collected from patients who underwent VATS between January 2013 and December 2022 at Peking Union Medical College Hospital (PUMCH). Univariable analyses and multivariable logistic regression analyses were used to determine the factors correlated with PoAF. Receiver operating characteristic (ROC) curve was used to evaluate the discrimination of the indicators to predict PoAF.

Results

The study enrolled 2920 patients, with a PoAF incidence of 5.2% (95% CI 4.4%-6.0%). In the logistic regression analyses, male sex (OR=1.496, 95% CI 1.056-2.129, P=0.024), left atrial anteroposterior dimension (LAD) ≥40 mm (OR=2.154, 95% CI 1.235-3.578, P=0.004), hypertension (HTN) without regular treatment (OR=2.044, 95% CI 0.961-3.921, P=0.044), a history of hyperthyroidism (OR=4.443, 95% CI 0.947-15.306, P=0.030), surgery of the left upper lobe (compared to other lung lobes) (OR=1.625, 95% CI 1.139-2.297, P=0.007), postoperative high blood glucose (BG) (OR=2.482, 95% CI 0.912-5.688, P=0.048), and the time of chest tube removal (per day postoperatively) (OR=1.116, 95% CI 1.038-1.195, P=0.002) were found to be significantly associated with PoAF. The area under the ROC curve was 0.707 (95% CI 0.519-0.799). 86.9% patients were successfully converted to sinus rhythm. Compared with the non-PoAF group, the PoAF group had significantly greater risks of prolonged air leakage, postoperative acute coronary syndrome, longer ICU stays, and longer hospital stays.

Conclusion

Male sex, LAD≥40 mm, HTN without regular treatment, a history of hyperthyroidism, surgery of the left upper lobe, postoperative BG, and the time of chest tube removal were associated with PoAF. These findings may help clinicians identify high-risk patients and take preventive measures to minimize the incidence and adverse prognosis of PoAF.

Ten-Year Trend of Oral Anticoagulation Use in Postoperative and Nonpostoperative Atrial Fibrillation in Routine Clinical Practice

BACKGROUND

The study aimed to describe the patterns and trends of initiation, discontinuation, and adherence of oral anticoagulation (OAC) in patients with new-onset postoperative atrial fibrillation (POAF), and compare with patients newly diagnosed with non-POAF.

METHODS AND RESULTS

This retrospective cohort study identified patients newly diagnosed with atrial fibrillation or flutter between 2012 and 2021 using administrative claims data from OptumLabs Data Warehouse. The POAF cohort included 118 366 patients newly diagnosed with atrial fibrillation or flutter within 30 days after surgery. The non-POAF cohort included the remaining 315 832 patients who were newly diagnosed with atrial fibrillation or flutter but not within 30 days after a surgery. OAC initiation increased from 28.9% to 44.0% from 2012 to 2021 in POAF, and 37.8% to 59.9% in non-POAF; 12-month medication adherence increased from 47.0% to 61.8% in POAF, and 59.7% to 70.4% in non-POAF. The median time to OAC discontinuation was 177 days for POAF, and 242 days for non-POAF. Patients who saw a cardiologist within 90 days of the first atrial fibrillation or flutter diagnosis, regardless of POAF or non-POAF, were more likely to initiate OAC (odds ratio, 2.92 [95% CI, 2.87-2.98]; P <0.0001), adhere to OAC (odds ratio, 1.08 [95% CI, 1.04-1.13]; P <0.0001), and less likely to discontinue (odds ratio, 0.83 [95% CI, 0.82-0.85]; P <0.0001) than patients who saw a surgeon or other specialties.

CONCLUSIONS

The use of and adherence to OAC were higher in non-POAF patients than in POAF patients, but they increased over time in both groups. Patients managed by cardiologists were more likely to use and adhere to OAC, regardless of POAF or non-POAF.

Estimating Vitamin K Antagonist Anticoagulation Benefit in People With Atrial Fibrillation Accounting for Competing Risks: Evidence From 12 Randomized Trials

BACKGROUND

Patients with atrial fibrillation have a high mortality rate that is only partially attributable to vascular outcomes. The competing risk of death may affect the expected anticoagulant benefit. We determined if competing risks materially affect the guideline-endorsed estimate of anticoagulant benefit.

METHODS

We conducted a secondary analysis of 12 randomized controlled trials that randomized patients with atrial fibrillation to vitamin K antagonists (VKAs) or either placebo or antiplatelets. For each participant, we estimated the absolute risk reduction (ARR) of VKAs to prevent stroke or systemic embolism using 2 methods-first using a guideline-endorsed model (CHA2DS2-VASc) and then again using a competing risk model that uses the same inputs as CHA2DS2-VASc but accounts for the competing risk of death and allows for nonlinear growth in benefit. We compared the absolute and relative differences in estimated benefit and whether the differences varied by life expectancy.

RESULTS

A total of 7933 participants (median age, 73 years, 36% women) had a median life expectancy of 8 years (interquartile range, 6-12), determined by comorbidity-adjusted life tables and 43% were randomized to VKAs. The CHA2DS2-VASc model estimated a larger ARR than the competing risk model (median ARR at 3 years, 6.9% [interquartile range, 4.7%-10.0%] versus 5.2% [interquartile range, 3.5%-7.4%]; P<0.001). ARR differences varied by life expectancies: for those with life expectancies in the highest decile, 3-year ARR difference (CHA2DS2-VASc model - competing risk model 3-year risk) was -1.3% (95% CI, -1.3% to -1.2%); for those with life expectancies in the lowest decile, 3-year ARR difference was 4.7% (95% CI, 4.5%-5.0%).

CONCLUSIONS

VKA anticoagulants were exceptionally effective at reducing stroke risk. However, VKA benefits were misestimated with CHA2DS2-VASc, which does not account for the competing risk of death nor decelerating treatment benefit over time. Overestimation was most pronounced when life expectancy was low and when the benefit was estimated over a multiyear horizon.

Management of Arrhythmias in the Cardiovascular Intensive Care Unit

Arrhythmias in the cardiovascular intensive care unit (CVICU) can be difficult to manage because of the complex hemodynamic and respiratory states of critically ill patients. Treating physicians must be educated to prevent, diagnose, and treat a multitude of tachyarrhythmias and bradyarrhythmias. In this review article, the authors outline a pragmatic approach to patient assessment, arrhythmia diagnosis, and management of the most common arrhythmias seen in the CVICU.

Exploring postoperative atrial fibrillation after non-cardiac surgery: mechanisms, risk factors, and prevention strategies

Atrial fibrillation (AF) stands as the most prevalent persistent arrhythmia and a common complication after surgical procedures. Although the majority of non-cardiac surgery patients experience postoperative AF (POAF) and the condition is typically self-limited and asymptomatic, its detrimental impact on patient outcomes, prolonged hospitalization, and heightened risk of stroke and overall mortality has become increasingly evident. Of significant concern, POAF emerges as a noteworthy risk factor for stroke, myocardial infarction, and mortality in comparison to patients with non-surgical atrial fibrillation. Multiple studies have corroborated the association between POAF and an elevated risk of stroke and mortality. The development of postoperative atrial fibrillation is multifactorial, with the inflammatory response being a primary contributor; additionally, factors such as hypovolemia, intraoperative hypotension, anemia, trauma, and pain can trigger POAF. Risk factors for POAF in non-cardiac surgery primarily relate to age, hypertension, obesity, prior cardiac disease, obstructive sleep apnea, and male sex. Prophylactic treatment with β-blockers, amiodarone, or magnesium has demonstrated efficacy, but further trials are warranted, especially in high-risk populations. This review provides an account of the incidence rate, pathophysiology, and prognosis of atrial fibrillation after non-cardiac surgery, elucidates the underlying mechanisms of its occurrence, and explores various preventive strategies investigated in this domain.

Prevention of perioperative stroke in patients undergoing non-cardiac surgery

About 300 million adults undergo non-cardiac surgery annually. Although, in this setting, the incidence of perioperative stroke is low, the absolute number of patients experiencing a stroke is substantial. Furthermore, most patients with this complication will die or end up with severe disability. Covert brain infarctions are more frequent than overt strokes and are associated with postoperative delirium, cognitive decline, and cerebrovascular events at 1 year after surgery. Evidence shows that traditional stroke risk factors including older age, hypertension, and atrial fibrillation are also associated with perioperative stroke; previous stroke is the strongest risk factor for perioperative stroke. Increasing evidence also suggests the pathogenic role of perioperative events, such as hypotension, new atrial fibrillation, paradoxical embolism, and bleeding. Clinicians involved in perioperative care should be aware of this evidence on prevention strategies to improve patient outcomes after non-cardiac surgery.

Validation of the Use of Discharge Diagnostic Codes for the Verification of Secondary Atrial Fibrillation in Administrative Databases

Background

"Secondary" atrial fibrillation (AF) denotes AF that is precipitated by short-term triggers and that may be reversible. Using administrative data to study secondary AF is of interest, but the ability of these data to verify secondary AF has not been studied.

Methods

We conducted a cross-sectional analysis of 1000 randomly selected hospitalizations of patients discharged alive between January 1, 2016 and March 31, 2020, with AF coded as the most responsible diagnosis (type 1), post-admit comorbidity (type 2), or secondary diagnosis (type 3). We compared diagnosis types to AF category (secondary or not) as determined by a physician blinded to the discharge diagnosis type. We calculated the positive predictive value (PPV) of the designation of secondary AF in comparison to physician determination.

Results

A total of 421 hospitalizations had AF documented as a type 2 diagnosis; this had a PPV of 94.8% for physician determination of secondary AF. After excluding hospitalizations with preexisting AF, and those for which AF type could not be determined by the physician, the PPV of a type 2 diagnosis (n = 391) for secondary AF was 99.7%. Type 3 diagnoses of AF (n = 222) mostly captured hospitalizations with preexisting AF (87.8% of type 3 diagnoses).

Conclusions

A type 2 diagnosis can be used to verify secondary AF in people who were first diagnosed with AF while hospitalized for other causes. This verification facilitates cohort studies and clinical trial recruitment of people with this AF subtype, although it should not be used to determine the prevalence or incidence of secondary AF.

Atrial Fibrillation

Evidence for diagnosis and treatment of atrial fibrillation (AF) has expanded substantially since 2017, when In the Clinic last considered this subject. Direct oral anticoagulants have become the predominant therapy for thromboembolic disease, and antidotes for these drugs are now available. Device-based left atrial appendage occlusion is frequently used in patients who cannot tolerate systemic anticoagulation, and growing evidence suggests that early rhythm control improves outcomes. Catheter ablation is now frequently performed to prevent recurrent AF. Managing risk factors for AF, such as hypertension, diabetes, and obesity, remains paramount in prevention of this condition.

Overestimation of anticoagulant benefit in patients with atrial fibrillation and low life expectancy: evidence from 12 randomized trials

Background

Patients with atrial fibrillation (AF) have a high rate of all-cause mortality that is only partially attributable to vascular outcomes. While the competing risk of death may affect expected anticoagulant benefit, guidelines do not account for it. We sought to determine if using a competing risks framework materially affects the guideline-endorsed estimate of absolute risk reduction attributable to anticoagulants.

Methods

We conducted a secondary analysis of 12 RCTs that randomized patients with AF to oral anticoagulants or either placebo or antiplatelets. For each participant, we estimated the absolute risk reduction (ARR) of anticoagulants to prevent stroke or systemic embolism using two methods. First, we estimated the ARR using a guideline-endorsed model (CHA ₂ DS ₂ -VASc) and then again using a Competing Risk Model that uses the same inputs as CHA ₂ DS ₂ -VASc but accounts for the competing risk of death and allows for non-linear growth in benefit over time. We compared the absolute and relative differences in estimated benefit and whether the differences in estimated benefit varied by life expectancy.

Results

7933 participants had a median life expectancy of 8 years (IQR 6, 12), determined by comorbidity-adjusted life tables. 43% were randomized to oral anticoagulation (median age 73 years, 36% women). The guideline-endorsed CHA ₂ DS ₂ -VASc model estimated a larger ARR than the Competing Risk Model (median ARR at 3 years, 6.9% vs. 5.2%). ARR differences varied by life expectancies: for those with life expectancies in the highest decile, 3-year ARR difference (CHA ₂ DS ₂ -VASc model - Competing Risk Model 3-year risk) was -1.2% (42% relative underestimation); for those with life expectancies in the lowest decile, 3-year ARR difference was 5.9% (91% relative overestimation).

Conclusion

Anticoagulants were exceptionally effective at reduced stroke risk. However, anticoagulant benefits were misestimated with CHA ₂ DS ₂ -VASc, which does not account for the competing risk of death nor decelerating treatment benefit over time. Overestimation was most pronounced in patients with the lowest life expectancy and when benefit was estimated over a multi-year horizon.

Sinus node dysfunction and atrial fibrillation-Relationships, clinical phenotypes, new mechanisms, and treatment approaches

Although the anatomical basis of the pathogenesis of sinus node dysfunction (SND) and atrial fibrillation (AF) is located primarily in the left and right atria, increasing evidence suggests a strong correlation between SND and AF, in terms of both clinical presentation and formation mechanisms. However, the exact mechanisms underlying this association are unclear. The relationship between SND and AF may not be causal, but is likely to involve common factors and mechanisms, including ion channel remodeling, gap junction abnormalities, structural remodeling, genetic mutations, neuromodulation abnormalities, the effects of adenosine on cardiomyocytes, oxidative stress, and viral infections. Ion channel remodeling manifests primarily as alterations in the "funny" current (I_f) and Ca²⁺ clock associated with cardiomyocyte autoregulation, and gap junction abnormalities are manifested primarily as decreased expression of connexins (Cxs) mediating electrical impulse propagation in cardiomyocytes. Structural remodeling refers primarily to fibrosis and cardiac amyloidosis (CA). Some genetic mutations can also cause arrhythmias, such as SCN5A, HCN4, EMD, and PITX2. The intrinsic cardiac autonomic nervous system (ICANS), a regulator of the heart's physiological functions, triggers arrhythmias.In addition, we discuss arrhythmias caused by viral infections, notably Coronavirus Disease 2019 (COVID-19). Similarly to upstream treatments for atrial cardiomyopathy such as alleviating CA, ganglionated plexus (GP) ablation acts on the common mechanisms between SND and AF, thus achieving a dual therapeutic effect.