Narrow QRS complex tachycardia presenting as palpitation.

Atrial fibrillation is the most common sustained cardiac arrhythmia. The rhythm in atrial fibrillation is irregular. Correct interpretation of the electrocardiogram (ECG) is essential. Atrial flutter can present as regular or irregular narrow QRS complex tachycardia. Knowledge of the ECG features of atrial flutter will help to differentiate it from paroxysmal supraventricular tachycardia. The treatment strategy in atrial fibrillation should focus on rhythm control vs. rate control, and anticoagulation should be started based on the calculated risk of systemic embolisation. Atrial flutter is a unique arrhythmia that has similar management strategies to those of atrial fibrillation; however, radiofrequency ablation is increasingly preferred due to its higher rate of efficacy and safety compared to pharmacological therapy.