I48

Atrial fibrillation and flutter (I48): ECG, causes, stroke risk, CHA₂DS₂-VA and the AF-CARE approach.

Atrial fibrillation and flutter (ICD-10 I48) are the most common sustained heart rhythm disorders. In atrial fibrillation (AF) the atria produce chaotic electrical activity instead of regular beats; they quiver rather than contract, and the ventricles beat irregularly and often fast. In atrial flutter a single re-entry circuit (usually around the tricuspid valve) drives the atria at about 300 beats per minute, and the ventricles usually respond to every second impulse (about 150/min). The main danger is stroke: blood stagnating in the atria, particularly in the left atrial appendage, can form clots that travel to the brain. AF also contributes to heart failure and reduced quality of life.

ICD-10 I48ArrhythmiaStroke prevention

AF on ECGirregular RR, no P waves

Flutter on ECGsawtooth waves ≈ 300/min

Stroke risk scoreCHA₂DS₂-VA

Anticoagulationrecommended if score ≥ 2

Figure 1. Top: sinus rhythm. Middle: atrial fibrillation — no P waves, wavy baseline and irregularly irregular QRS complexes. Bottom: atrial flutter with sawtooth waves and 2:1 conduction (about 150/min).

Causes and risk factors

Older age, hypertension, heart failure, valve disease (especially mitral), coronary disease, obesity, diabetes, sleep apnoea, alcohol, hyperthyroidism, chronic kidney and lung disease, and sometimes intense endurance sport. AF can be triggered by infections, surgery or alcohol excess. Sometimes no cause is found.

Symptoms

Palpitations, irregular pulse, breathlessness, fatigue, reduced exercise tolerance, dizziness or chest discomfort. Many people have no symptoms, so AF is often found by chance or only after a stroke. It may be paroxysmal (stopping by itself), persistent or permanent.

Management (the AF-CARE approach)

C – comorbidities and risk factors: treat hypertension, heart failure, diabetes, sleep apnoea, obesity; reduce alcohol; regular activity
A – avoid stroke and thromboembolism: oral anticoagulation (preferably a direct oral anticoagulant) is recommended with a CHA₂DS₂-VA score of 2 or more and should be considered with a score of 1; aspirin is not an alternative
R – reduce symptoms by rate and rhythm control: beta-blockers, diltiazem/verapamil or digoxin for rate; cardioversion, antiarrhythmic drugs or catheter ablation for rhythm. Catheter ablation of the flutter circuit cures typical flutter in most patients
E – evaluation and dynamic reassessment of risks and treatment over time

Call emergency services

for signs of stroke (sudden face drooping, arm weakness, speech difficulty), or palpitations with chest pain, severe breathlessness, fainting or confusion.

References

Van Gelder IC, Rienstra M, Bunting KV, et al. 2024 ESC Guidelines for the management of atrial fibrillation. Eur Heart J. 2024;45(36):3314–3414. doi:10.1093/eurheartj/ehae176

This article is for general information and does not replace a consultation with a doctor. Diagnosis and treatment must be decided by a physician on the basis of symptoms, examination and tests.

Published on 23 March 2019

Medical Book