For Patients & General Readers

Atrial fibrillation, or AFib, is a common heart rhythm disorder where the upper chambers of the heart beat irregularly and often too quickly. It can affect anyone, but is more common in older adults and those with other heart conditions. AFib is important because it significantly increases the risk of stroke and other heart problems if not properly managed.

Clinical Overview

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, characterized by disorganized atrial electrical activity leading to ineffective atrial contraction. This often results in an irregularly irregular ventricular response, increasing the risk of thromboembolic events, particularly stroke.

Clinical Presentation

Often asymptomatic, detected incidentally on routine physical examination or ECG.
Palpitations, described as a fluttering, racing, or pounding sensation in the chest.
Dyspnea on exertion or at rest.
Fatigue or reduced exercise tolerance.
Dizziness or lightheadedness.
Chest pain or discomfort (less common, may indicate underlying ischemia).

Signs & Symptoms

Symptoms (Patient-Reported)

Feeling my heart race or skip beats
Shortness of breath
Feeling tired or weak
Dizziness
Chest discomfort
Feeling anxious

Signs (Clinician-Observed)

Irregularly irregular pulse on palpation.
Absence of 'a' waves in jugular venous pulsations.
S3 or S4 gallop may be present.
Evidence of heart failure (e.g., peripheral edema, rales).

Differential Diagnoses

Condition	Distinguishing Feature
Atrial Flutter	Characterized by a regular 'sawtooth' pattern on ECG, typically with a consistent conduction ratio (e.g., 2:1, 3:1).
Supraventricular Tachycardia (SVT)	Usually presents with a regular, rapid heart rate, often with a narrow QRS complex. P waves may be absent or retrograde.
Ventricular Tachycardia (VT)	Characterized by wide QRS complexes and a regular but often rapid heart rate. P waves are typically dissociated.
Sinus Tachycardia	Heart rate is regular and follows physiological stimuli (e.g., exercise, fever, anxiety). P waves are present and normal.
Sick Sinus Syndrome	Can manifest as bradycardia, pauses, and alternating episodes of AF or flutter, but the underlying issue is sinus node dysfunction.
Paroxysmal Supraventricular Tachycardia (PSVT)	Episodes of rapid, regular heart rhythm originating above the ventricles, often starting and stopping abruptly.

Red Flags — Seek Immediate Care

Hemodynamic instability (hypotension, altered mental status, shock) in the setting of new-onset AF.
Acute chest pain suggestive of myocardial infarction.
Signs of acute stroke (FAST criteria: Face drooping, Arm weakness, Speech difficulty, Time to call 911).
Severe dyspnea or signs of acute pulmonary edema.

Key Investigations

Electrocardiogram (ECG) to confirm diagnosis and assess rate/rhythm.
Holter monitor or event recorder for suspected paroxysmal AF.
Echocardiogram (transthoracic) to assess cardiac structure, function, and valvular disease.
Blood tests: complete blood count (CBC), electrolytes, renal function, thyroid function tests (TSH), liver function tests (LFTs).
Consider cardiac biomarkers (troponin) if ischemic symptoms are present.
Consider transesophageal echocardiogram (TEE) for pre-cardioversion assessment of thrombus.

Management Overview

Management of atrial fibrillation focuses on stroke risk reduction, rate control, rhythm control, and management of underlying causes. Anticoagulation is paramount for stroke prevention, with risk stratification using CHA2DS2-VASc score. Rate control is achieved with beta-blockers, calcium channel blockers, or digoxin, while rhythm control may involve antiarrhythmic drugs or electrical/pharmacological cardioversion.

Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. TruelyserMD does not replace clinical judgement.