Do baseline atrial electrocardiographic and infarction patterns predict new-onset atrial fibrillation after ST-elevation myocardial infarction? Insights from the Assessment of Pexelizumab in Acute Myocardial Infarction Trial

Association of Angina, Myocardial Infarction and Atrial Fibrillation-A Bidirectional Mendelian Randomization Study

Aims/Background Coronary heart disease (CHD) and atrial fibrillation (AF) exhibit a close relationship, yet the existing body of research predominantly relies on observational study methodologies, posing challenges in establishing causal relationships. The objective of our study is to investigate the causal linkages between coronary atherosclerosis (CAAs), angina pectoris, myocardial infarction (MI), and AF. Methods This study utilizes a two-sample Mendelian randomization (TSMR) methodology, leveraging genetic variation as a means of evaluating causality. Mendelian randomization is grounded in three primary assumptions: (1) the genetic variant is linked to the exposure, (2) the genetic variant is independent of confounding factors, and (3) the genetic variant influences the outcome solely through the exposure. Results The results of our study suggest a genetic predisposition in which CAAs, angina, and MI may enhance susceptibility to AF, while AF may reciprocally elevate the risk of CAAs. Conclusion In light of these findings, it is recommended that patients with CHD undergo regular cardiac rhythm monitoring, and that patients with AF receive anticoagulant and antiplatelet therapy whenever feasible. This study posits a practical implication for clinical practice.

Acute atrial infarction: a relatively neglected and under-recognized entity in clinical practice

BACKGROUND

Electrocardiograms (ECGs) and angiographic features indicative of acute atrial infarction (AAI) often go unnoticed and are under-recognized in clinical practice.

METHODS

In this retrospective observational study, we analyzed the data of 3981 out of 9803 patients (40.61%) who were referred to our hospital for angiography and/or percutaneous coronary intervention due to acute coronary syndrome (ACS). These patients were diagnosed with acute ST segment elevation myocardial infarction (AMI) affecting the inferior, posterior, and/or right ventricular regions.

RESULTS

Of the 3981 patients, 270 (6.78%) had involvement of the main coronary atrial branch meeting the angiographic criteria for AAI. Among the 270 patients identified, the right coronary artery was diagnosed as the infarct-related artery (IRA) in 187 patients (group R), while the left circumflex artery was the IRA in 83 patients (group L). The incidence of PR-segment deviation was similar between the two groups (65.2% in group R vs. 66.3% in group L, p = 0.870), as was occurrence of atrial tachyarrhythmia (67.4% vs. 55.4%, p = 0.059). The prevalence of P wave morphology abnormalities (29.9% vs. 49.4%, p = 0.005) and sinus bradycardia or arrest (25.1% vs. 66.3%, p < 0.001) was significantly lower in Group R than in Group L.

CONCLUSION

Acute atrial infarction represents a distinct yet frequently overlooked clinical entity. Clinicians should consider the potential for atrial arrhythmias, thromboembolism, hemodynamic instability, and atrial rupture when diagnosing AAI.

Electrocardiographic Predictors of Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common pathological arrhythmia, and its complications lead to significant morbidity and mortality. However, patients with AF can often go undetected, especially if they are asymptomatic or have a low burden of paroxysms. Identification of those at high risk of AF development may help refine screening and management strategies.

METHODS

PubMed and Embase databases were systematically searched for studies looking at electrocardiographic predictors of AF from inception to August 2021.

RESULTS

A total of 115 studies were reported which examined a combination of atrial and ventricular parameters that could be electrocardiographic predictors of AF. Atrial predictors include conduction parameters, such as the PR interval, p-wave index and dispersion, and partial interatrial or advanced interatrial block, or morphological parameters, such as p-wave axis, amplitude and terminal force. Ventricular predictors include abnormalities in QRS amplitude, morphology or duration, QT interval duration, r-wave progression and ST segment, i.e., t-wave abnormalities.

CONCLUSIONS

There has been significant interest in electrocardiographic prediction of AF, especially in populations at high risk of atrial AF, such as those with an embolic stroke of undetermined source. This review highlights the breadth of possible predictive parameters, and possible pathological bases for the predictive role of each parameter are proposed.

The frequency of atrial infarction in patients with supraventricular arrhythmias

Aim      To evaluate the incidence of atrial infarction (AI) based on a retrospective review of 287 case reports of patients with supraventricular arrhythmia and a positive qualitative test for troponin I after pharmacological arrest of arrhythmia; to determine the target localization of lesions and diagnostic signs, that appear in acute ischemic atrial damage, by selective coronary angiography (CA).Material and methods  A retrospective review was performed of 287 case reports of patients admitted to cardiology departments for atrial fibrillation paroxysm with narrow QRS complexes on electrocardiogram (ECG) from 2018 through 2020. At the prehospital stage, verapamil had been administered intravenously with no effect. In the hospital, the sinus rhythm was successfully restored pharmacologically in all patients. Then ECG, repeated qualitative determination of troponin I, echocardiography, and CA were performed.Results 77 (27 %) patients of the study group had AI signs; 27 (9.5 %) of these patients had confirmed AI, and 50 (17.5 %) patients had probable AI. The existence of acute ischemic injury was considered absolutely confirmed in the presence of a combination of ECG changes, positive markers of myocardial damage, and reduced blood flow velocity in the left atrial branch of the sinoatrial nodal artery as shown by CA; in the presence of only ECG and biochemical criteria, acute AI was considered probable. According to selective CA, coronary injuries requiring an intervention were absent, and signs of the above-mentioned artery thrombosis were not visualized. However, the blood flow velocity was reduced to the TIMI II level in 9.5 % of cases; other atrial branches had an extremely small diameter.Conclusion      Atrial infarction needs to be excluded for patients with supraventricular arrhythmias, a characteristic clinical picture, and increased levels of myocardial injury enzymes.

The interplay between atrial fibrillation and acute myocardial infarction

Atrial fibrillation is the most frequently occurring supraventricular arrhythmia in patients presenting with acute myocardial infarction. It is associated with worse outcomes when it coexists with acute myocardial infarction and results in increased morbidity and mortality. Both conditions are closely related to each other and share similar pathophysiological pathways. The management of atrial fibrillation in patients with acute myocardial infarction is challenging since triple antithrombotic therapy is indicated, but this results in a markedly increased risk of bleeding events and mortality. This review addresses the interactions between both conditions including common risk factors, possible mechanisms through which acute myocardial infarction contributes to development of atrial fibrillation and vice versa, and the problem of using anticoagulation in the management of these patients.

Coronary heart disease and atrial fibrillation: a vicious cycle

The population suffering from coronary heart disease (CHD) complicated by atrial fibrillation (AF) is rising rapidly. A strong correlation between the two diseases has been reported, and the many common risk factors they share may play prominent roles in their development. In addition, CHD can directly promote the progression of AF by affecting reentry formation, focal ectopic activity, and neural remodeling. At the same time, AF also affects CHD through three aspects: 1) atherosclerosis, 2) the mismatch of blood supply and oxygen consumption, and 3) thrombosis. In conclusion, CHD and AF can aggravate each other and seem to form a vicious cycle. For patients with CHD complicated by AF, principal studies and guidelines have focused on antithrombotic treatment and rhythm control, which are paramount for these patients. Of note, our review sheds light on the strategies to break the cycle of the two diseases, which may be fundamental to treat these patients and optimize the benefit.

ECG analysis in patients with acute coronary syndrome undergoing invasive management: rationale and design of the electrocardiography sub-study of the MATRIX trial

BACKGROUND

The twelve‑lead electrocardiogram (ECG) has become an essential tool for the diagnosis, risk stratification, and management of patients with acute coronary syndromes (ACS). However, several areas of residual controversies or gaps in evidence exist. Among them, P-wave abnormalities identifying atrial ischemia/infarction are largely neglected in clinical practice, and their diagnostic and prognostic implications remain elusive; the value of ECG to identify the culprit lesion has been investigated, but validated criteria indicating the presence of coronary occlusion in patients without ST-elevation are lacking; finally, which criteria among the multiple proposed, better define pathological Q-waves or success of revascularisation deserve further investigations.

METHODS

The Minimizing Adverse hemorrhagic events via TRansradial access site and systemic Implementation of AngioX (MATRIX) trial was designed to test the impact of bleeding avoidance strategies on ischemic and bleeding outcomes across the whole spectrum of patients with ACS receiving invasive management. The ECG-MATRIX is a pre-specified sub-study of the MATRIX programme which aims at analyzing the clinical value of ECG metrics in 4516 ACS patients (with and without ST-segment elevation in 2212 and 2304 cases, respectively) with matched pre and post-treatment ECGs.

CONCLUSIONS

This study represents a unique opportunity to further investigate the role of ECGs in the diagnosis and risk stratification of ACS patients with or without ST-segment deviation, as well as to assess whether the radial approach and bivalirudin may affect post-treatment ECG metrics and patterns in a large contemporary ACS population.

Early Versus Late New-Onset Atrial Fibrillation in Acute Myocardial Infarction: Differences in Clinical Characteristics and Predictors

New-onset atrial fibrillation (NOAF) during acute myocardial infarction (AMI) has significant consequences but is often misdiagnosed. The aim of the study was to evaluate predictors of NOAF throughout different phases of AMI. Patients with AMI admitted to a tertiary medical center were analyzed. Exclusion criteria were preexisting AF, AMI onset ≥24 hours prior to admission, in-hospital death, significant valvular disease, and in-hospital coronary artery bypass graft. Study population were AMI without-NOAF, early-AF (AF terminated within 24 hours of admission), and late-AF (beyond the first 24 hours). Overall 5946 patients were included, age: 64.8 ±14.8 years; 30% women. The incidence of NOAF was 4.6%: 1.6% early-AF, and 3% late-AF. Patients with NOAF comprised greater rate of women, cardiovascular risk-factors burden, severe left ventricular-dysfunction, pulmonary hypertension, valvular disorders, and left atrial enlargement compared with patients without-NOAF. Non-ST-elevation myocardial infarction and inferior-ST-elevation myocardial infarction (STEMI) were significantly more prevalent among early-AF group, while anterior-STEMI, in late-AF. The final multivariate models showed c-statistics of 0.73 and 0.76 for the prediction of new-onset early-AF and late-AF, respectively. In conclusion, there are different clinical predictors of early- versus late-NOAF. The study points out “high risk” AMI population for more meticulous heart rate monitoring for NOAF.

Electrocardiographic diagnosis of atrial infarction in patients with acute inferior ST-segment elevation myocardial infarction

BACKGROUND

Patients with atrial myocardial infarction (ATMI) have frequent cardiac and noncardiac complications. However, ATMI is uncommonly diagnosed because of its nonspecific ECG changes. Our objective was to analyze the ECG characteristics of ATMI in patients with inferior STEMI.

HYPOTHESIS

Electrocardiographic P wave parameters can help in diagnosis of ATMI.

METHODS

We evaluated 932 patients who underwent coronary angiography and recruited 39 patients with ATMI and 33 patients without ATMI with inferior STEMI for a retrospective study. Twelve-lead ECGs were obtained to measure P-wave parameters in diagnosis of ATMI. P-wave parameters and PR-segment displacement were compared in patients with and without ATMI.

RESULTS

In inferior leads, PWD and PWDisp were significantly longer in the ATMI group than in the non-ATMI group (limb lead II, 109.79 ±15.51 ms and 86.65 ±5.02 ms, respectively; P < 0.001; limb lead III, 108.31 ±12.51 ms and 85.27 ±7.47 ms, P < 0.001; aVF, 106.49 ±13.68 ms and 83.01 ±7.89 ms, P < 0.001; PWDisp, 41.67 ±10.72 ms and 25.18 ±5.17 ms, P < 0.001). By contrast, PWA was significantly lower in the ATMI group than in the non-ATMI group (limb lead II, 0.96 ±0.18 mV and 1.39 ±0.22 mV, respectively; P < 0.001; limb lead III, 0.90 ±0.11 and 1.21 ±0.23, P < 0.001; aVF, 0.88 ±0.17 and 1.26 ±0.28, P < 0.001). PR-segment displacement was found in 8 (20.5%) patients with ATMI. A PWD ≥95.5 ms in lead DII diagnosed ATMI with a higher sensitivity and specificity (90%, 94%) than did PWA or PWDisp.

CONCLUSIONS

This study suggests P-wave parameters might be considered ECG findings in diagnosis of ATMI in patients with inferior STEMI.

Prognostic significance of abnormal P wave morphology and PR-segment displacement after ST-elevation myocardial infarction

INTRODUCTION

Atrial infarction is uncommonly diagnosed and data on its significance are limited. Its incidence in ST-elevation myocardial infarction (STEMI) reportedly ranges from 0.7-42%. Certain atrial ECG changes, such as abnormal P wave morphology suggestive of atrial involvement have been associated with 90-day mortality after STEMI. However, whether atrial ECG changes are associated with short (30-day) or long-term (1-year) mortality have not been studied.

METHODS

We examined index ECG in 224 consecutive STEMI. Demographics, clinical variables, peak troponin I, ejection fraction, and angiographic data were collected. Atrial ECG patterns were examined and correlated with mortality.

RESULTS

Length of stay was longer with abnormal P waves (p=0.008) or PR displacement in any lead (p=0.003). Left main coronary disease was more prevalent with abnormal P wave (p=0.045). Abnormal P wave morphology in any lead was associated with higher 30-day (OR 3.09 (1.35-7.05)) and 1-year mortality (OR 5.33 (2.74-10.36)). PR displacement in any lead was also associated with increased 30-day (OR 2.33 (1.03-5.28)) and 1-year mortality (OR 6.56 (3.34-12.86)). Abnormal P wave, PR depression in II, III and AVF, and elevation in AVR or AVL were associated with increased 1-year mortality (OR 12.49 (5.2-30.0)) as was PR depression in the precordial leads (OR 21.65 (6.82-68.66)). After adjusting for age, ejection fraction, peak troponin I, and left main disease, PR displacement in any lead was associated with increased 1-year mortality (adjusted OR 6.22 (2.33-18.64)).

CONCLUSION

PR segment displacement in any lead, found in 31% of patients with STEMI, independently predicted 1-year mortality.

Atrial fibrillation in acute ST-elevation myocardial infarction: clinical and prognostic features

Atrial fibrillation (AF) is a common arrhythmia in the setting of acute coronary syndrome and acute ST-elevation myocardial infarction (STEMI). This review summarizes recent evidence on the clinical and prognostic significance of pre-existent and new-onset AF in acute STEMI patients and highlights new emerging predictors of AF development in the era of contemporary treatment.