Atrial fibrillation: What is atrial fibrillation / Afib / AF? - The complete Guide

Atrial fibrillation is a cardiac arrhythmia in which the atria fires uncontrollably due to damage to the atrial-endocardium (inner layer of the cardiac muscle of the atria). Atrial fibrillation is commonly abbreviated as A-fib, Afib, or simply AF.

Types of Atrial fibrillation

There are two classifications according to their duration and clinical presentation pattern:

• First episode: the initial episode in a previously undiagnosed patient, regardless of event duration and related symptoms.
• Paroxysmal: an episode that reverts spontaneously and lasts between 48 hours and seven days.
• Persistent: episode lasting more than seven days and less than one year.
• Long-standing persistent: duration greater than or equal to one year in a patient undergoing management to restore sinus rhythm.
• Permanent: episode lasting more than one year. Agreements between the doctor and the patient in the search for strategies to control sinus rhythm.
• Isolated Atrial fibrillation: due to the better knowledge of pathophysiology in each patient, there is a cause for this arrhythmia.
• Valvular/Nonvalvular Atrial fibrillation: this classification includes patients with moderate/severe mitral stenosis or mechanical heart valves.
• Chronic Atrial fibrillation: should not be used since it has several definitions and does not distinguish between permanent or persistent A-fib

What is the ICD 10 code for Atrial fibrillation / Afib / AF?

The ICD / ICD 10 code for Atrial fibrillation / Afib / AF is "I48" (Atrial fibrillation and flutter under the range - Diseases of the circulatory system.).

Atrial fibrillation symptoms

A-fib can present clinically in two ways: asymptomatic and symptomatic. The most frequent symptoms are:

• Palpitations
• Dyspnea
• Chest pain
• Tiredness when making physical effort
• Dizziness
• Syncope
• Generalized sweating
• General weakness

Atrial fibrillation: What are the causes and risk factors?

The causes of Atrial fibrillation may be anatomical factors, which condition alterations in the transmission of the cardiac electrical impulse (fibrosis, dilation of the atrium), leading to electrophysiological aspects.

Risk factors for Atrial fibrillation:

• Cardiac diseases: diseases such as heart failure, valve disease, ischemic heart disease, congenital heart disease, cardiomyopathies, conduction disorders, pericardial diseases,
• Advanced age
• Habits: such as smoking and alcoholism
• Genetic predisposition
• Other diseases: include hypertension, diabetes, obesity, chronic kidney disease, thyroid problems, respiratory diseases, immune/rheumatic diseases, and thromboembolic diseases.
• Previous surgery: particularly cardiac and thoracic
• Emotional factors or stress
• Inflammatory state or infection
• Medication use: medications such as steroids, caffeinated pain relievers, bronchodilators, and expectorants (used for asthma and cough) can speed up the heart rate.

Atrial fibrillation: Can It Be Prevented?

Some risk factors for Atrial fibrillation, such as age and genetics, are out of your control; but a healthy lifestyle can help prevent disease or avoid complications from Atrial fibrillation and other heart conditions that involve arrhythmias. Risk factors that are modifiable include:

• Quit smoking, drinking alcohol, and consuming caffeine, cocaine, and other stimulants.
• Control your blood pressure.
• Maintain a healthy weight and a heart-healthy diet high in plant foods and low in saturated fat.
• Exercising helps prevent or slow recurrences of Atrial fibrillation.
• Constant regular treatment of chronic diseases because it reduces the chances of cardiovascular risk and the appearance of Atrial fibrillation.

Atrial fibrillation: How is it diagnosed?

A complete medical history should emphasize the diagnosis of a patient with Atrial fibrillation. It is essential to describe the clinical presentation of the patient (duration, intensity, and frequency, as well as signs/symptoms), precipitating factors (exercise, emotion, toxic agents), and associated diseases (heart disease, diabetes, hypertension, obesity, thyroid disorders, lung disorders, infections).

Subsequently, the physical examination is of great importance, in this case, the cardiovascular assessment. Then complementary tests such as an electrocardiogram, laboratory tests, cardiac function studies, ultrasound, and imaging studies are requested.

It is essential to perform an electrocardiogram, which can demonstrate an episode of Atrial fibrillation (presence of irregular atrial activation, absence of P waves, and irregular RR intervals).

Blood tests include complete blood count, electrolytes, renal function, transaminases, thyroid hormones, and biomarkers such as natriuretic peptides or troponin.

The chest radiograph helps assess concomitant findings of heart failure or other culprit diseases.

 Transthoracic echocardiogram (TTE): to evaluate the function and dimensions of the left ventricle, the sizes of the left atrium, the presence of valve disease, the dimensions of the right ventricle, and systolic function.

Transesophageal echocardiogram (TEE): helpful in evaluating valvulopathies or detecting thrombi in the left atrial appendage.

Electrocardiogram-Holter: It is an ambulatory electrocardiographic monitoring device performed at home and used in patients with suspected Atrial fibrillation who didn't achieve a diagnosis by ECG or when rate control needs monitoring.

Coronary angiography: useful in patients with signs or symptoms of ischemic heart disease.

CT or cerebral MRI: when suspected of a heart attack or cerebral embolism.

Electrophysiological study: in case of suspicion of pre-excitation syndrome.

What are the treatments for Atrial fibrillation?

After making the diagnosis of Atrial fibrillation, the physician must evaluate the thrombotic and hemorrhagic risk, as well as the anticoagulant treatment decided individually following the following scheme:

1. Heart rate monitoring
2. Heart rate monitoring
3. Thromboembolic prevention

Atrial fibrillation Treatment: Heart Rate Control

It is an integral part of treating Atrial fibrillation and is usually sufficient to improve symptoms without requiring rhythm control. Depending on the patient, control can be more strict (heart rate <80 beats per minute), or it can be a little laxer (heart rate <110 beats per minute), taking into account clinical events, cardiac functional class, and hospital admissions).

In addition, possible underlying causes, such as active infection or anemia, can cause decompensation, and their treatment achieves a symptomatic improvement of the arrhythmia.

Atrial fibrillation Treatment: Drugs

Available drug treatment includes beta-blockers (such as bisoprolol, nebivolol, or metoprolol), digoxin, calcium channel blockers (diltiazem and verapamil), or combination therapy.

Some antiarrhythmic drugs also affect the heart rate (amiodarone, dronedarone, and, to some extent, propafenone); avoid in patients in whom management by rate control alone

is vital.

The choice by the treating physician must take into account the characteristics of the patients, the symptoms, the cardiac pumping, and the hemodynamic state.

In the case of critically ill patients in whom the oral route is not available, intravenous amiodarone is an option. In patients with hemodynamic instability, urgent cardioversion is helpful.

Atrial fibrillation Treatment: Atrioventricular Node Ablation and Pacemaker

Atrioventricular node ablation and pacemaker implantation could control the ventricular rate when pharmacological measures are ineffective.

The procedure is simple, and the rate of complications and mortality is low.

In young patients, AV node ablation is an option when heart rate control is urgent, and other options have been exhausted.

Atrial fibrillation Treatment: Heart Rhythm Control

Rhythm control strategy refers to attempts to restore and maintain sinus rhythm. There are several treatments for this purpose, among which the following stand out:

• Cardioversion, either pharmacological or electrical.
• Catheter ablation.
• Surgery.
• Hybrid procedures: surgery and catheter ablation.

The main indication for choosing a rhythm control strategy is to reduce symptoms and improve the patient's quality of life with Atrial fibrillation.

Before considering carrying out a rhythm control strategy, consider a series of factors that may favor the result:

• Young patients. The first episode of Atrial fibrillation or Atrial fibrillation of short duration.
• Tachycardia-mediated cardiomyopathy.
• A standard or moderate increase in left atrial volume index or atrial conduction delay (little atrial remodeling).
• None or few comorbidities or heart disease.
• Heart rate challenging to control.
• Atrial fibrillation precipitated by acute illness.
• Patient preferences.

Atrial fibrillation Treatment: Cardioversion

In unstable patients, it is necessary to perform cardioversion immediately, electrical cardioversion being usually the most effective choice.

In stable patients, elective cardioversion, either electrical or pharmacological, can be performed.

There are several risk factors for the recurrence of Atrial fibrillation after cardioversion. These factors are advanced age, female gender, previous cardioversion, chronic obstructive pulmonary disease (COPD), renal failure, structural heart disease, increased LA volume index, and heart failure.

Elective cardioversion is contraindicated in the presence of thrombi in the left atrium.

Pharmacological cardioversion: it is an elective procedure indicated in hemodynamically stable patients. Regarding the efficacy of the drugs, they restore sinus rhythm in 50% of patients with new-onset Atrial fibrillation.

• Flecainide and Propafenone: these can only be used in patients without structural heart disease, as they are negative inotropes and are dangerous in patients with reduced cardiac function.
• Vernakalant is the drug with the fastest cardioversion effect, being more effective than amiodarone or flecainide. It is contraindicated in patients with acute coronary syndrome or severe heart failure.
• Amiodarone is a safe drug for ischemic heart disease and heart failure, influencing heart rate control.
• Catheter ablation: It is a safe procedure and more effective than antiarrhythmic drugs in restoring and maintaining sinus rhythm and improving symptoms.

Treatment of Atrial fibrillation: Anticoagulation

Correct oral anticoagulation is necessary, agreed upon between the doctor and the patient, considering each patient's thrombotic and hemorrhagic risk.

The thrombotic risk determines the choice of anticoagulant without considering the arrhythmia's clinical pattern. Available anticoagulation options include vitamin K antagonists and oral anticoagulants such as dabigatran, rivaroxaban, apixaban, and edoxaban.

Complications of Atrial fibrillation

Early diagnosis of Atrial fibrillation and proper treatment avoids associated complications such as thrombosis and embolism.

Thrombosis: due to the stagnation of blood within the atrial cavities, due to the inefficient contractility of the atria, thrombi are formed, which adhere to the atrial walls, causing damage and obstruction. These thrombi favor the formation of other thrombi.

Embolism: this complication is a consequence of thrombosis because, with the disordered movement of the atrium, these thrombi can detach, migrating within the bloodstream until they reach some territory outside the heart, obstructing circulation in that area.

This condition, also known as thromboembolism, and the manifestations of this embolism depend on the affected territory. If it is a thrombus in the right atrium, the thrombus may migrate to the lungs (pulmonary embolism), while in the left atrium, it may go to any other part of the body. , affecting this area.

However, not all territories are equally important, so within the different types of embolism, there is one that stands out above the rest: cerebral embolism, whose consequences, sometimes dramatic, occur five times more frequently in people who have Atrial fibrillation than in those whose heart rhythm is normal.

Heart failure: Due to the loss of the support provided by atrial activity to the heartbeat, the heart muscle strains and changes its muscular structure, thus altering its function and pumping sufficient blood to the body.

Atrial fibrillation: How to live with Atrial fibrillation?

Like any cardiovascular disease, the treatment of Atrial fibrillation includes knowing the risks and complications and seeing a doctor when presenting symptoms or having risk factors or family history.

The risk of complications can be minimized or eliminated through adequate medical treatment, individualized according to the conditions of each patient, through drugs, interventional procedures, or surgery.

The patient's collaboration relies on lifestyle changes, such as changes in diet and reduction of harmful habits, which can be essential in preventing complications and having a better quality of life without severe limitations.