A 15-year-old girl gave a recent history of dyspnoea and “funny turns”. She had congenital aortic stenosis, previous valvotomies, a mechanical valve replacement, permanent pacemaker, atrial tachyarrhythmias, impaired ventricular function, systemic hypotension, pulmonary hypertension, and anxiety. The diagnosis of diaphragmatic flutter was delayed due to all the differential diagnoses and rarity of the condition. It was confirmed by observation, respiratory band monitoring, volume-time spirogram and fluoroscopy during an attack.