Orphanet_844 (Atrial tachyarrhythmia with short PR interval) can be described as follows. Lown-Ganong-Levine syndrome is an extremely rare conduction disorder characterized by a short PR interval (less than or equal to 120 ms) with normal QRS complex on electrocardiogram associated with the occurrence of episodes of atrial tachyarrythmias (e.g. atrial fibrillation, atrial tachycardia). Also known as: Lown-Ganong-Levine syndrome.