Supraventricular tachycardias are rapid cardiac arrhythmias that originate in the atria. They usually appear on the ECG as narrow complex tachycardia, but under certain circumstances (preexisting block pattern, aberration, and accessory conduction bundle) they can also appear as wide complex tachycardia. Tachycardias with reentry mechanism are distinguished from those with abnormal automaticity or triggered activity. Since most supraventricular tachycardias (SVTs) can be cured with catheter ablation, a treatment option with low risks, this should be generously recommended. The most common supraventricular tachycardia is atrial fibrillation, whose prevalence has reached endemic proportions and is associated with significant morbidity and mortality. Atrial fibrillation is a complex disease, so a detailed characterization of these patients is necessary. The therapy planning includes stroke prevention, symptom control, and treatment of comorbidities.