Atrial Fibrillation: Symptoms, Risks, and Treatment Options

Atrial fibrillation (AFib) is the most common sustained cardiac arrhythmia in the world, affecting more than 37 million people globally. In this condition, the atria (upper chambers of the heart) stop contracting in a coordinated manner and instead quiver or fibrillate chaotically, producing an irregular and often rapid heart rhythm. Although it is not always an immediate emergency, atrial fibrillation increases the risk of embolic stroke five to seven times and can progressively deteriorate heart function if not properly diagnosed and treated.

What exactly is atrial fibrillation

In a heart with normal rhythm, an electrical signal originates in the sinus node (the natural pacemaker located in the right atrium) and propagates in an orderly fashion through the atria and then to the ventricles, producing a coordinated and efficient contraction. In atrial fibrillation, hundreds of abnormal electrical impulses fire simultaneously and in a disorganized manner throughout the atria, causing them to quiver at rates of 350 to 600 times per minute instead of contracting effectively. The ventricles respond to these impulses irregularly, generating an arrhythmic pulse that the patient may perceive as palpitations.

Atrial fibrillation is classified according to its duration and behavior:

• ●Paroxysmal: episodes that start and stop spontaneously, generally lasting less than 7 days. Many episodes resolve within 24 hours
• ●Persistent: the arrhythmia continues for more than 7 days and requires medical intervention (medications or electrical cardioversion) to restore normal rhythm
• ●Long-standing persistent: atrial fibrillation has continued uninterrupted for more than 12 months
• ●Permanent: a joint decision has been made between doctor and patient not to attempt rhythm restoration, and treatment focuses exclusively on controlling heart rate and preventing embolism

Symptoms of atrial fibrillation

Symptoms vary enormously between patients. Some people experience intensely bothersome symptoms while others feel absolutely nothing, and the arrhythmia is discovered incidentally during a routine electrocardiogram:

• ●Palpitations: sensation of rapid, irregular, strong, or disordered heartbeats in the chest, which is the most common symptom and the one that generates the most concern
• ●Disproportionate fatigue: loss of effective atrial contraction reduces cardiac output by 15% to 25%, causing tiredness with activities that previously caused no fatigue
• ●Shortness of breath: especially during physical exertion such as climbing stairs, walking quickly, or exercising
• ●Dizziness or unsteadiness: caused by the irregularity of the heart rhythm and resulting blood pressure fluctuations
• ●Chest pain or pressure: a sensation of tightness in the chest that can be confused with other cardiac conditions
• ●Marked decrease in exercise tolerance: inability to maintain the level of physical activity previously performed
• ●Anxiety and distress: the constant or episodic perception of irregular heartbeats generates worry and anguish in many patients

Risk factors: who is most vulnerable

• ●High blood pressure: the most prevalent risk factor, present in the majority of patients diagnosed with atrial fibrillation
• ●Advanced age: prevalence increases significantly after age 65, affecting approximately 10% of people over 80
• ●Heart valve disease: mitral stenosis and mitral regurgitation strongly predispose to atrial fibrillation
• ●Heart failure: both a cause and consequence of atrial fibrillation in a vicious cycle
• ●Obesity: excess weight independently increases risk through atrial remodeling
• ●Obstructive sleep apnea: an increasingly recognized risk factor that contributes to the atrial arrhythmogenic substrate
• ●Diabetes mellitus: increases risk through chronic inflammation and atrial remodeling
• ●Excessive alcohol consumption: the so-called holiday heart syndrome, particularly with acute excessive intake
• ●Hyperthyroidism: a classic and potentially reversible cause of atrial fibrillation that must be ruled out in every new patient
• ●Coronary artery disease and history of myocardial infarction

Stroke risk: the most feared complication

The most serious complication of atrial fibrillation is embolic stroke. When the atria fibrillate without contracting effectively, blood stagnates and can form clots, especially in a structure called the left atrial appendage. If a clot breaks loose and travels through the bloodstream to the brain, it can block a cerebral artery and cause a potentially devastating stroke.

Stroke risk is assessed using the CHA2DS2-VASc score, which assigns points for: heart failure, hypertension, age (65-74 = 1 point, 75 or older = 2 points), diabetes, prior stroke or transient ischemic attack (2 points), vascular disease, and female sex. Based on the total score, the cardiologist determines whether the patient needs oral anticoagulation to prevent stroke.

Current treatment options

Treatment of atrial fibrillation is based on three fundamental pillars:

• ●Heart rate control: medications such as beta-blockers (metoprolol, bisoprolol), calcium channel blockers (diltiazem, verapamil), or digoxin to keep the ventricular rate within an acceptable range (generally between 60 and 110 beats per minute), even though the arrhythmia persists
• ●Rhythm control (restoring normal sinus rhythm): electrical cardioversion (synchronized electrical shock under brief sedation), anti-arrhythmic drugs (amiodarone, flecainide, propafenone) to maintain sinus rhythm, or catheter ablation that isolates the pulmonary veins using radiofrequency or cryoenergy with success rates of 70-80% in the first session
• ●Stroke prevention through oral anticoagulation: direct oral anticoagulants (apixaban, rivaroxaban, dabigatran, edoxaban) have largely replaced warfarin due to their superior safety profile and elimination of the need for periodic blood test monitoring

Prevention and lifestyle changes

• ●Strictly control blood pressure with medications and healthy habits
• ●Maintain a healthy body weight: losing 10% of body weight in obese patients significantly reduces the frequency and duration of atrial fibrillation episodes
• ●Treat sleep apnea if present; CPAP use substantially improves arrhythmia control
• ●Moderate alcohol and caffeine consumption, known triggers of episodes
• ●Engage in moderate regular aerobic exercise, consulting with your cardiologist about appropriate intensity
• ●Control diabetes and cholesterol with prescribed treatments
• ●Learn to check your pulse regularly to detect if your heart rhythm becomes irregular

When to seek emergency medical care

Go to the emergency room immediately if you experience: palpitations accompanied by severe chest pain, severe breathing difficulty that does not improve with rest, sudden weakness on one side of the body or difficulty speaking (signs of stroke), fainting or loss of consciousness, or sustained heart rate greater than 150 beats per minute with intense symptoms. Atrial fibrillation diagnosed in time and treated correctly allows you to lead a normal, active, and safe life.

Dr. Elders Jimenez Iglesias

Cardiologist · Nuclear Cardiology

Professional License: 13819257 · Specialty: 12543211