A 58-year-old male was referred to our outpatient cardiology clinic for evaluation of atrial fibrillation, fatigue, dizziness and exertional dyspnoea. He had suffered recurrent pneumonia in childhood. Beside an irregular pulse, the physical examination was normal. Electrocardiography showed atrial fibrillation (ventricular response of 60 to 70 beats/min), a right bundle branch block and nonspecific repolarisation abnormalities. Pulmonary vascular redistribution was visible on chest X-ray (figure 1).