A 59-year-old woman with visible precordial pulsations

CLINICAL INTRODUCTION: A retired 59-year-old woman presented to the cardiology clinic concerned with cardiac pulsations that were visible on her chest wall. These were not associated with dyspnoea, syncope or chest discomfort.Of note, 8 years previously, she complained of recurrent nocturnal diaphoresis and 5 kg weight loss. Blood sampling at that time revealed a microcytic anaemia, reactive thrombocytosis and raised inflammatory markers (erythrocyte sedimentation rate 99 mm/hour, C-reactive protein 161 mg/L). Following an episode of transient diplopia, ophthalmoscopy demonstrated a cotton wool spot in the left inferotemporal retinal arcade. She commenced a 2-year tapering course of 1 mg/kg prednisolone.On examination, she had a lean physique with a supine blood pressure of 162/60 mm Hg and palpable Corrigan's pulse. She had a prominent apical pulsation and a loud early diastolic murmur was present at the left sternal edge radiating to the apex. Echocardiography showed severe central aortic regurgitation and a dilated aortic root (see online supplementary figure 1). Cardiac CT was performed to clarify the diagnosis (figure 1).DC1SP110.1136/heartjnl-2017-312193.supp1Supplementary file 1 heartjnl;104/3/273/F1F1F1Figure 1Contrast-enhanced CT of the thorax at index presentation (A) and 6 months (B). Prospective ECG-gated cardiac CT angiogram (75% R-R interval) performed at 8 years from index presentation (C) with a stretched multiplanar reconstruction of the aortic annulus, aortic root and thoracic aorta (D).

Which of the following diagnoses best explains this presentation?Ankylosing spondylitisTakayasu arteritisSalmonellosisIgG4-related aortitisGiant cell aortitis.