7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate Official reprint from UpToDate www.uptodate.com 2023 UpToDate, Inc. and/or its affiliates. All Rights Reserved. Atrial fibrillation: Overview and management of new- onset atrial fibrillation : Kapil Kumar, MD : Peter J Zimetbaum, MD : Nisha Parikh, MD, MPH All topics are updated as new evidence becomes available and our peer review process is complete. Literature review current through: Jun 2023. This topic last updated: Mar 22, 2023. INTRODUCTION Atrial fibrillation (AF) is the most commonly treated cardiac arrhythmia. AF is generally associated with an irregularly irregular ventricular rhythm and absence of distinct P waves. This topic will provide a broad overview of the classification, clinical presentation, diagnosis, management, and sequelae of AF, including new-onset AF. The initiation and maintenance of AF reflect electrophysiologic alterations in atrial myocardium. The pathophysiology of AF is discussed in detail elsewhere. (See "Mechanisms of atrial fibrillation".) The epidemiology of AF including prevalence, risk factors, and associated chronic conditions is discussed in detail separately. (See "Epidemiology, risk factors, and prevention of atrial fibrillation".) The following topics provide detail about specific types of AF and other management issues: (See "Atrial fibrillation in adults: Use of oral anticoagulants".) (See "Management of atrial fibrillation: Rhythm control versus rate control".) (See "Control of ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy".) https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 1/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate CLASSIFICATION AND TERMINOLOGY AF can be classified according to its duration and length of episodes; these were described in the 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society guidelines on AF management [1]. Paroxysmal (ie, self-terminating or intermittent) AF Paroxysmal AF is defined as AF that terminates spontaneously or with intervention within seven days of onset. Episodes may recur with variable frequency. (See "Paroxysmal atrial fibrillation".) Persistent AF Persistent AF is defined as AF that fails to self-terminate within seven days. Episodes often require pharmacologic or electrical cardioversion to restore sinus rhythm. While a patient who has had persistent AF can have later episodes of paroxysmal AF, AF is generally considered a progressive disease. Long-standing persistent AF Long-standing persistent AF refers to AF that has lasted for more than 12 months. Permanent AF Permanent AF is a term used to identify persistent AF for which a joint decision by the patient and clinician has been made to no longer pursue a rhythm control strategy. Acceptance of persistent AF may change as symptoms, therapeutic options, and patient and clinician preferences evolve [1]. While AF typically progresses from paroxysmal to persistent states, patients can present with both types throughout their lives. AF can also be classified based by the way it presents or whether specific valvular conditions are present: Subclinical or occult AF This refers to AF that is largely asymptomatic and only becomes apparent in the setting of a thromboembolic event, acute heart failure exacerbation, other medical illness, or upon routine electrocardiogram (ECG) done for other purposes. (See "Cryptogenic stroke and embolic stroke of undetermined source (ESUS)", section on 'Occult atrial fibrillation' and "Overview of the evaluation of stroke", section on 'Monitoring for subclinical atrial fibrillation' and 'Common scenarios' below.) Screening for AF is discussed separately. (See 'Screening' below.) Valvular AF This refers to patients with moderate to severe mitral stenosis; these patients have a higher risk of stroke than patients without this condition. https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 2/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate Lone AF The term "lone AF" is a historical term that is now disfavored, as it may be confusing and does not enhance patient care [1,2]. The term lone AF has been used to describe AF in younger patients (eg, 60 years) with paroxysmal, persistent, or permanent AF who have no structural heart disease or cardiovascular risk factors. These characteristics identify a group of individuals with a CHA DS -VASc score of "0" and who are at lowest risk 2 2 for thromboembolism from AF. (See "Atrial fibrillation in adults: Selection of candidates for anticoagulation", section on 'CHA2DS2-VASc score'.) SCREENING We do not currently screen asymptomatic patients for AF. In a general population and among persons >65 years of age, screening has not been shown to be better than usual care (eg, pulse palpation on physical examination) for AF detection. Furthermore, screening showed modest to no benefit on reducing cardiovascular outcomes and death in one of two randomized studies. Screening may lead to more anticoagulation, but this has not been shown to be associated with robust protection from stroke or thromboembolic events [3-5]. The United States Preventive Services Task Force (USPSTF) also does not recommend screening for AF. Effects on cardiovascular outcomes and death Two randomized studies of screening for AF (with either single-lead ECGs or implantable loop recorders) showed only a modest or no reduction in clinical events and are also limited in that they included a narrow patient population that may not be widely generalizable. A randomized, unmasked, parallel group study in Sweden (STROKESTOP) of 28,768 individuals aged 75 to 76 years compared outcomes (ie, a composite of ischemic or hemorrhagic stroke, systemic embolism, bleeding leading to hospitalization, and all-cause death) in patients who underwent two-week intermittent ECG screening with subsequent anticoagulation strategy versus those who received usual care [3]. After a median follow-up of 6.9 years, somewhat fewer outcomes occurred in the intervention group than in the control group (5.45 versus 5.68 events per 100 years; hazard ratio [HR] 0.96; 95% CI 0.92- 1.00), but the overall risks and absolute benefit are very low. However, despite this low absolute risk reduction, an analysis using a Markov model based on the STROKESTOP study suggested that screening for AF in this older adult population may still be cost effective and possibly even cost saving [6]. In the LOOP study, 6004 individuals with stroke risk factors were randomly assigned to either implantable loop recorder monitoring (also called implantable cardiac monitor) or usual care [4]. Those in the implantable loop recorder group had three times the rates of https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 3/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate AF detection and anticoagulation initiation but no change in rates of stroke or arterial embolization. AF detection Data are mixed as to whether screening for AF increases the number of new AF cases detected; however, the potential benefit appears to be small at best. The choice of test used to detect AF and population characteristics likely impacts these results. In the VITAL-AF trial, 16 primary clinics were randomly assigned either to AF screening using a handheld single-lead ECG (AliveCor KardiaMobile) during vital sign assessments or to usual care [7]. More than 30,000 patients 65 years of age were followed for one year for the development of new-onset AF. New AF diagnosis in the screening and control groups was similar (1.72 versus 1.59 percent). In a prespecified subgroup analysis of persons aged 85 years, new AF diagnoses were more frequent in the screening versus control group (5.56 versus 3.76 percent). In a meta-analysis of three cluster randomized studies (not including VITAL-AF), screening identified more cases of AF compared with no screening when using one-time approaches (pulse palpation, ECG, and/or Holter monitor [absolute risk difference range 0.06 to 0.60 percentage points; relative risk range 1.04 to 1.58]). However, this difference was small and statistically significant in only one of the studies in the meta-analysis [5]. The Apple Watch in combination with iPhone application was evaluated in over 400,000 individuals without a history of AF [8]. Irregular pulse notifications were sent to 2161 participants (0.52 percent). Of these, 450 participants were sent and returned an ECG patch and were not otherwise excluded per study protocol. AF was present in 34 percent of 450 patients. Among those who were notified of an irregular pulse on the watch while wearing the patch, 84 percent were concordant with AF. The Apple Watch study did not employ the gold standard reference of 12-lead ECG analyzed by two cardiologists, which limits interpretation of device accuracy for AF detection. Accuracy of detection method The accuracies of specific AF detection tests were reviewed by the USPSTF [5]. In most studies, test accuracy was measured against the reference of 12-lead ECG (interpreted by two cardiologists). Sensitivity and specificity were generally high for single-lead ECG and oscillometric blood pressure monitors. Implantable cardiac monitors are more sensitive than ECG and external monitoring [9]. ECGs do not appear more effective than pulse palpation at AF detection. A USPSTF review of randomized trials and observational studies (17 studies and 135,300 patients age 65 years and older) found that systematic screening with ECG identified more cases of AF than no screening (absolute increase from 0.6 to 2.8 percent over 12 months) [10]. However, https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 4/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate systematic screening with ECG did not detect more cases than a systematic approach using pulse palpation. Enrichment of population to be screened Although at this time there is no sufficient evidence to screen for AF in broad populations, focusing screening efforts on patients at significantly higher risk for development of AF may be more fruitful. Using the CHADS2- VASc score can be a starting point, but risk scores such as the CHARGE-AF score derived from clinical variables [11], or a polygenic risk score derived from genetic testing [12] may potentially be more effective. The role of evaluating patients with cryptogenic stroke for AF is discussed separately. (See "Cryptogenic stroke and embolic stroke of undetermined source (ESUS)", section on 'Occult atrial fibrillation'.) CLINICAL PRESENTATION Symptoms AF may or may not have associated symptoms, and the spectrum of symptoms is broad and nonspecific. Typical symptoms include the following: Palpitations Tachycardia Fatigue Weakness Dizziness Lightheadedness Reduced exercise capacity Increased urination Mild dyspnea. Some patients have more severe symptoms. These include the following: Dyspnea at rest Angina Presyncope or rarely syncope Symptoms of stroke or other systemic embolic event Symptoms of heart failure (eg, dyspnea on exertion, peripheral edema, weight gain, and abdominal swelling from ascites) https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 5/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate The severity and extent of symptoms are affected by the patient's underlying cardiac condition, age, presence of diabetes [13,14], and rapidity and regularity of the ventricular response. For example, one study of 2400 AF patients showed that the 420 patients with diabetes felt fewer AF- related symptoms (eg, palpitations, dizziness, exercise intolerance [odds ratio 0.74; 95% CI 0.59- 0.92]), but had a worse quality of life (beta = -4.54; 95% CI -6.40 to -2.68) than those without diabetes [13]. Quality of life was measured on the 100-point European Quality of Life-5 Dimensions Questionnaire (EQ-5D). The hemodynamic consequences of AF are discussed in detail separately. (See "Hemodynamic consequences of atrial fibrillation and cardioversion to sinus rhythm".) Common scenarios A new diagnosis of AF may result from several clinical scenarios that are described below: At the time of a routine examination, during which the patient complains of symptoms possibly due to AF or is being evaluated for another reason and is found to have an irregularly irregular pulse. On an ECG obtained for other reasons such as a preoperative evaluation. (See "The electrocardiogram in atrial fibrillation".) A patient with a stroke or other arterial thromboembolism can be found to have AF that had not been previously diagnosed [15]. In some cases, AF is detected during extended monitoring in an attempt to diagnose the cause for the stroke. (See "Stroke in patients with atrial fibrillation" and "Cryptogenic stroke and embolic stroke of undetermined source (ESUS)", section on 'Occult atrial fibrillation'.) Subclinical AF can be also detected by intracardiac, implantable, or wearable monitors [16]. Subclinical AF usually occurs in individuals without characteristic symptoms of AF and without a prior diagnosis. Most of these individuals will have paroxysmal AF. A scientific statement from the American Heart Association on subclinical and cardiac implantable electronic device-detected AF was published in 2019 [16]. (See "Ambulatory ECG monitoring" and "Paroxysmal atrial fibrillation", section on 'Evaluation' and "Implantable cardioverter-defibrillators: Overview of indications, components, and functions", section on 'ECG monitoring and storage'.) The ASSERT study of 2580 patients (65 years or older) with either a dual-chamber pacemaker or implantable cardioverter-defibrillator, hypertension, and no history of AF found that at three months, subclinical AF was detected in about 10 percent of patients [17]. Clinical AF developed in about 16 percent of patients with subclinical AF. https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 6/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate In a study of 590 individuals with stroke risk factors but without AF who underwent screening with an implantable loop recorder for an average of 40 months, 35 percent of participants were found to have AF [9]. During ECG monitoring with a 24-hour ambulatory monitor obtained for some other reason or during interrogation of an implanted cardiac rhythm device. (See "Ambulatory ECG monitoring" and "Implantable cardioverter-defibrillators: Overview of indications, components, and functions", section on 'ECG monitoring and storage'.) During hospitalization for another reason such as infection, recent myocardial infarction, thyrotoxicosis, pulmonary embolism, chronic obstructive pulmonary disease, myocarditis, and pericarditis, among others [18-21]. (See "Arrhythmias in COPD" and "Cardiovascular effects of hyperthyroidism" and "Pneumococcal pneumonia in patients requiring hospitalization", section on 'Cardiac events and other noninfectious complications'.) During or after cardiac or noncardiac surgery. (See "Atrial fibrillation in patients undergoing noncardiac surgery" and "Atrial fibrillation and flutter after cardiac surgery" and "Arrhythmias during anesthesia", section on 'Atrial fibrillation'.) During recording from a patient-acquired recording device (eg, Apple watch, AliveCor KardiaMobile, etc). (See "The electrocardiogram in atrial fibrillation", section on 'Wearable consumer devices' and 'Screening' above.) EVALUATION History and physical examination Descriptions of any associated symptoms should include: Onset or date of discovery Possible precipitating factors Frequency and duration Severity of episodes and symptoms Qualitative characteristics Previous medical records of any prior supraventricular arrhythmias A semi-quantitative method to classify symptoms has been developed, but the clinical utility of such a system has not been demonstrated [22]. Associated conditions The presence and status of associated conditions such as other cardiovascular disease, cerebrovascular disease, diabetes, hypertension, chronic obstructive pulmonary disease, obstructive sleep apnea should be ascertained. (See https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 7/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate "Epidemiology, risk factors, and prevention of atrial fibrillation" and "Arrhythmias in COPD", section on 'Atrial fibrillation' and "Obstructive sleep apnea and cardiovascular disease in adults", section on 'Atrial fibrillation'.) The presence of potentially reversible causes should be assessed (eg, hyperthyroidism, unhealthy alcohol use). (See "Overview of the clinical manifestations of hyperthyroidism in adults" and "Diagnosis of hyperthyroidism" and "Risky drinking and alcohol use disorder: Epidemiology, pathogenesis, clinical manifestations, course, assessment, and diagnosis".) Physical examination The physical examination should focus on the cardiovascular system and any associated conditions. Abnormal findings may inform healthcare providers about associated conditions that might be contributing to the onset of AF and/or impacting the severity. Examples include heart murmurs or arterial pulse abnormalities indicative of mitral or aortic stenosis or regurgitation, hypertrophic cardiomyopathy, and signs and symptoms of heart failure. (See "Examination of the precordial pulsation" and "Auscultation of cardiac murmurs in adults" and "Examination of the jugular venous pulse" and "Examination of the arterial pulse".) During AF with an irregularly irregular pulse, there is commonly a slight variation in the intensity of the first heart sound. S4 sounds are not heard, and jugular venous "a" waves are absent since atrial contraction is lost. (See "Auscultation of heart sounds", section on 'Clinical significance of S4'.) An apical-radial pulse deficit is commonly observed in patients in AF. When one assesses the rates of the left ventricular apex and the radial pulse simultaneously, the radial pulse rate may be less than the apical heart rate. Since the heart rate is irregular, some ventricular contractions will occur, preceded by shorter periods of diastole in which there is a reduction in left ventricular filling. This results in ventricular beats with insufficient stroke volume to transmit the pressure wave to the arm. Variation in cuff blood pressure readings is also common during AF due to changes in the beat-to-beat cadence and changes in left ventricular filling and stroke volume. It is often necessary to measure the blood pressure multiple times and average these values to obtain a more accurate blood pressure readings. In addition, automated blood pressure machines may have difficulty in accurately measuring blood pressure during AF, so a manual blood pressure check is recommended. Electrocardiogram For all patients with suspected new-onset AF, we obtain a 12-lead ECG. On an ECG with AF, there are no discrete P waves but rapid, low-amplitude, continuously varying fibrillatory (f) waves are seen. The ventricular rhythm is generally irregularly irregular (lacking a repetitive pattern), although AF is uncommonly associated with a regular ventricular rate. The https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 8/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate ECG in patients with AF is described in detail separately ( waveform 1). (See "The electrocardiogram in atrial fibrillation".) There are a number of potential pitfalls in the ECG diagnosis of AF. Errors in the diagnosis of AF are especially common with computerized ECG interpretation and in patients who are continuously or intermittently paced. Hence, it is important that the automated ECG interpretation provided by the machine is confirmed by a skilled reader. A baseline ECG, preferably in sinus rhythm, should also be evaluated for the following information: Markers of nonelectrical cardiac disease, such as left ventricular hypertrophy (possible hypertension) or Q waves (possible coronary artery disease). Markers of electrical heart disease, including the presence of ventricular pre-excitation or infranodal conduction disease (bundle branch block). The QT interval (to identify the potential risk of antiarrhythmic therapy) Evidence of severe bradycardia or sinus node dysfunction Echocardiogram We obtain a transthoracic echocardiogram (TTE) even if the physical examination is otherwise normal. We obtain a TTE in order to evaluate the size of the right and left atria and the size and systolic function of the right and left ventricles; to detect possible valvular heart disease, left ventricular hypertrophy, diastolic dysfunction, and pericardial disease; and to assess peak right ventricular and right atrial pressures. The TTE may also identify left atrial thrombus, although the sensitivity is low. Transesophageal echocardiography is much more sensitive for identifying thrombi in the left atrium or left atrial appendage and can be used to determine the need for anticoagulation prior to any attempt at pharmacologic or electrical cardioversion. (See "Role of echocardiography in atrial fibrillation" and 'Anticoagulation' below.) Additional cardiac testing We refer patients with signs or symptoms of ischemic heart disease for exercise testing. (See "Exercise ECG testing: Performing the test and interpreting the ECG results" and "Stress testing for the diagnosis of obstructive coronary heart disease".) Exercise testing is useful to help guide pharmacotherapy for AF, as some antiarrhythmic medications are contraindicated in patients with coronary artery disease. (See "Antiarrhythmic drugs to maintain sinus rhythm in patients with atrial fibrillation: Recommendations", section on 'Selecting an antiarrhythmic drug'.) https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 9/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate Ambulatory cardiac monitoring with event recorders, adhesive extended time event monitors, or insertable cardiac monitors (also sometimes referred to as implantable cardiac monitors or implantable loop recorders) can be used to identify the arrhythmia if it is intermittent and not captured on routine ECG. Ambulatory ECG monitoring can also be utilized to correlate symptoms to the arrhythmia along with assessment of the AF burden. Twenty-four- to 48-hour Holter monitoring mainly aids in the evaluation of overall ventricular response rates in individuals where a rate control strategy has been chosen and there is concern for inadequate heart rate control or bradycardia. (See "Ambulatory ECG monitoring".) Laboratory testing We obtain a complete blood count, serum electrolytes, and assessment of renal function, particularly in patients for whom a nonvitamin oral anticoagulant might be started. We do not order troponin unless acute ischemia is suspected. Clinical or subclinical hyperthyroidism is present in less than 5 percent of patients with AF [23]. A thyroid-stimulating hormone and free T4 levels should be obtained in all patients with a first episode of AF, or in those who develop an increase in AF frequency. (See "Epidemiology, risk factors, and prevention of atrial fibrillation", section on 'Hyperthyroidism'.) Other important baseline tests include a complete blood count to assess for underlying anemia or sign of infection and evaluation for diabetes mellitus [24]. (See "Clinical presentation, diagnosis, and initial evaluation of diabetes mellitus in adults".) Other tests A chest radiograph may be a useful diagnostic test in selected patients with evidence of dyspnea and potential heart failure or risk of pneumonia. (See "Heart failure: Clinical manifestations and diagnosis in adults", section on 'Chest radiograph'.) INITIAL MANAGEMENT A useful framework for the general care of AF patients (including those with new-onset as well as longstanding AF) is the ABC (Atrial Fibrillation Better Care) pathway [25,26]. "A" can be considered for anticoagulation "B" for better symptom management "C" for cardiovascular risk factor and comorbid disease assessment and management. Observational studies [27,28], a post-hoc analysis of the AFFIRM trial [29], and a prospective randomized trial using a mobile application [30] suggest that the implementation of such a framework of care for AF patients may have a salutary impact on adverse cardiovascular events and hospitalizations, while being cost saving for healthcare systems [31]. https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 10/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate Management setting Outpatient versus emergency department Whereas most patients with newly diagnosed AF can often be managed in an outpatient setting, some unstable patients require direct hospital admission or transfer to emergency department from an outpatient setting. Indications for transfer to a facility with emergency services include the following: Hemodynamic instability and/or shock (manifested as hypotension, confusion, acute kidney injury, etc). Suspected or confirmed myocardial ischemia/infarction. Suspected or confirmed heart failure. (See "The management of atrial fibrillation in patients with heart failure".) Evidence of pre-excitation (eg, Wolff-Parkinson-White syndrome) on the ECG. Extreme, uncontrolled tachycardia. Severe symptoms that may require more urgent rate or rhythm control. Hypotension for which AF is suspected to be causal or contributory and for which standard therapy to treat underlying causes and hypotension have failed. Care must be given to other potentially inciting factors such as sepsis, fluid depletion, or vasodilation. For patients whose AF is thought to be secondary to an initiating comorbidity such as pneumonia, treatment of the underlying cause of AF is important and may reduce the long- term risk of recurrent AF. Finally, for those patients who require urgent management, we generally obtain the same baseline diagnostic tests as in stable patients unless other clinical characteristics suggest otherwise. In this case, the diagnostic approach should also include work-up for the suspected underlying condition (eg, pneumonia, pulmonary embolus, etc). Indications for hospitalization Many patients with new-onset AF who are evaluated in an emergency room may not need to be hospitalized. However, indications for hospitalization in these patients include: Patients in whom ablation of an accessory pathway is being considered, particularly if the AF was highly symptomatic and associated with hemodynamic collapse and rapid ventricular response rate. https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 11/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate Severe bradycardia or prolonged pauses, including after cardioversion. (See "Sinus node dysfunction: Epidemiology, etiology, and natural history".) Treatment of an associated medical problem, which is often the reason for the arrhythmia (eg, hypertension, infection, exacerbation of chronic obstructive pulmonary disease, pulmonary embolism, pericarditis, persistent myocardial ischemia). It should be noted that AF alone is not an indication to rule out myocardial infarction. Further management of heart failure or hypotension after control of the rhythm or rate. Initiation of antiarrhythmic drug therapy (if patient and drug characteristics necessitate hospitalization). Difficult-to-control ventricular rates with evidence of ischemia, congestive heart failure symptoms or signs, and severe symptoms are indications for at least a 24-hour admission. Referral to cardiologist AF is a common medical problem and can often be managed by primary care physicians without need for consultation with a cardiologist. We suggest patient referral when the physician is not comfortable with decision-making or when catheter ablation of AF is under consideration. Also, when cardioversion or antiarrhythmic drugs are contemplated, cardiology consultation is advantageous. Anticoagulation Every patient with AF should be evaluated for the need for antithrombotic therapy to prevent systemic embolization even for the first AF episode. This is accomplished by use of a risk-scoring system for incident stroke called the CHA DS -VASc score ( table 1). Other 2 2 factors that may improve prediction of risk of stroke for an individual patient with burden of AF include left atrial size and function and certain biomarkers (ie, NT-proBNP and high-sensitivity troponin-T) [32]. Patients who require antithrombotic therapy include those in whom cardioversion (whether electrically or pharmacologically) to sinus rhythm is being considered (regardless of the CHA DS -VASc score or method of cardioversion [electrical or pharmacologic]) 2 2 and those who meet criteria for long-term anticoagulation. All patients whose risk of embolization exceeds the risk of bleeding are candidates for long-term antithrombotic therapy. These issues are discussed in detail elsewhere. (Related Pathway(s): Atrial fibrillation: Anticoagulation for adults with atrial fibrillation.) Triggers In some cases, onset of AF is triggered by another acute medical diagnosis: hyperthyroidism, acute pulmonary embolism, myopericarditis, pneumonia, after cardiac surgery, and certain drugs or supplements. Treatment of specific triggers or elimination of inciting factors may lead to years or even a lifetime without further episodes of AF. https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 12/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate The treatment of a suspected precipitating cause may result in reversion to sinus rhythm. For patients with severe hyperthyroidism, the main goal of therapy initially is rate control, anticoagulation, treatment of hyperthyroidism, and restoration of sinus rhythm once they are euthyroid. (See "Graves' hyperthyroidism in nonpregnant adults: Overview of treatment", section on 'Therapeutic approach'.) Treatment of AF in patients with heart failure and/or chronic obstructive pulmonary disease should generally be undertaken simultaneously with treatment of their other condition. (See "The management of atrial fibrillation in patients with heart failure", section on 'Correction of reversible causes'.) Cardiovascular risk factors Identifying and treating risk factors and comorbidities may help with AF symptoms and burden. Common risk factors and comorbidities that can lead to the development of AF include advanced age, hypertension, diabetes, obstructive sleep apnea, heart failure, and obesity. For most identified risk factors, we believe that treating the risk factor may reduce but not eliminate the likelihood of subsequent episodes of AF. A comprehensive description of risk factors for AF is discussed separately. (See "Epidemiology, risk factors, and prevention of atrial fibrillation", section on 'Chronic disease associations' and "Overview of established risk factors for cardiovascular disease".) Symptom and hemodynamic management Unstable patients In some hemodynamically unstable patients who manifest with signs or symptoms such as hypotension, altered mental status, or heart failure, we attempt ventricular rate control. Slowing of the ventricular rate will sometimes lead to spontaneous reversion to sinus rhythm. Rate control is usually performed with a beta blocker or calcium channel blocker (verapamil or diltiazem). This is discussed in detail separately. (See "Control of ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy".) For patients with AF and heart failure, ventricular rate control strategies are discussed separately. (See "The management of atrial fibrillation in patients with heart failure", section on 'Rate control in heart failure with reduced ejection fraction'.) If the patient remains hemodynamically unstable, emergency cardioversion should be performed, particularly if the hemodynamic compromise is due to an uncontrolled rapid ventricular rate and/or we believe that the lack of atrial contraction is impairing cardiac output. Emergent therapy with rate control and/or cardioversion for unstable patients is discussed separately. (See "Atrial fibrillation: Cardioversion", section on 'Unstable patients' and "Control of https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 13/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate ventricular rate in patients with atrial fibrillation who do not have heart failure: Pharmacologic therapy", section on 'Determining urgency'.) Unless AF reverts spontaneously, a decision is made whether, when, and how cardioversion will be performed. Management of thromboembolic risk is a key consideration when cardioversion is considered. (See "Atrial fibrillation: Cardioversion" and "Prevention of embolization prior to and after restoration of sinus rhythm in atrial fibrillation".) If we decide to perform emergency cardioversion, the risk for a thromboembolic event needs to be considered. Most patients who will undergo cardioversion should be anticoagulated as soon as the decision is made to cardiovert or after assessment of their clinical thromboembolic risk based on their CHA DS -VASc score. Issues related to anticoagulation around the time of 2 2 cardioversion are discussed in detail separately. (See "Prevention of embolization prior to and after restoration of sinus rhythm in atrial fibrillation", section on 'AF duration less than 48 hours' and "Atrial fibrillation: Cardioversion" and "Prevention of embolization prior to and after restoration of sinus rhythm in atrial fibrillation".) Once the patient becomes hemodynamically stable, the remainder of the acute and long-term management is similar to that of stable patients. Stable patients For stable patients with new-onset AF who do not meet the above criteria for emergency management and in whom we have performed an evaluation, we try to accomplish the following in the outpatient setting: Evaluate the need to slow the ventricular rate. Discuss the possible need for cardioversion with the patient. If the patient is highly symptomatic or if there is new-onset AF even in the absence of symptoms, we usually attempt cardioversion. Among patients with new-onset AF, even if cardioversion is contemplated, it usually does not need to be performed urgently; the majority of these patients will spontaneously convert to sinus rhythm within 48 to 72 hours [33]. Among 1822 patients admitted to the hospital because of AF, 356 had an arrhythmia duration less than 72 hours. Sixty-eight percent of the patients with this short AF duration spontaneously reverted to sinus rhythm [33]. Two-thirds of those with spontaneous reversion had AF duration of less than 24 hours; AF duration less than 24 hours was the only predictor of spontaneous reversion. A detailed discussion of cardioversion, including reasons to not cardiovert, is found elsewhere. (See "Atrial fibrillation: Cardioversion" and "Management of atrial fibrillation: Rhythm control versus rate control", section on 'Summary and recommendations'.) https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 14/35 7/5/23, 9:11 AM Atrial fibrillation: Overview and management of new-onset atrial fibrillation - UpToDate The choice of electrical or pharmacologic cardioversion requires consideration of the efficacy and safety of the approach, comorbidities, stability, preferences of the patient, and comfort of the clinician to use one or the other approach. This issue is discussed in detail elsewhere. (See "Atrial fibrillation: Cardioversion", section on 'Electrical versus pharmacologic cardioversion'.) Determine the need for acute and long-term anticoagulant therapy. Discuss the cause (if known) and natural history of AF. (See 'Sequelae' below.) Consider consultation with a cardiologist. Reasons to consult a cardiologist include the need for cardioversion or the need to treat with antiarrhythmic drugs or catheter ablation. (See 'Management setting' above.) Schedule follow-up. (See 'Long-term management' below.) LONG-TERM MANAGEMENT Early follow-up Follow-up after an episode of acute AF is necessary to evaluate the safety and efficacy of rate or rhythm control, patient adherence with anticoagulant and antiarrhythmic therapy, need for continued therapies for AF, to discuss any strategies to reduce AF recurrence, and to assess the functional status of the patient. For many patients, a one-week follow-up visit, or as soon as possible if one week is not realistic for a particular patient, is a reasonable strategy. This early return is particularly important for patients started on antiarrhythmic drug therapy to assess safety, efficacy, and side effects that can be specific to their therapy. (See "Antiarrhythmic drugs to maintain sinus rhythm in patients with atrial fibrillation: Recommendations".) Prevention of thromboembolism Following initial pre- and postcardioversion anticoagulation, the decision to continue long-term anticoagulation following a single reversible incident is debatable, and the decision is highly individualized based on the presumed future risk of recurrent AF in that individual (vis a vis CHA DS -VASc score). It is also reasonable to take 2 2 an observational approach following a reversible cause of AF involving clinical follow-up of symptoms and ambulatory monitoring for surveillance for possible recurrence. (See "Atrial fibrillation in adults: Selection of candidates for anticoagulation".) Anticoagulation shared-decision making The shared decision-making between patients and providers includes benefits versus risks of taking anticoagulation and tradeoffs between warfarin and DOAC; providers should also be prepared to address patients https://www.uptodate.com/contents/atrial-fibrillation-overview-and-management-of-new-onset-atrial-fibrillation/print 15/35 7/5/23, 9:11 AM