Abstract::Early detection of aortic dilatation in ankylosing spondylitis using echocardiography. D. Thomas, W. Hill, R. Geddes, M. Sheppard, J. Arnold, J. Fritzsche and P. M. Brooks,Aust. N.Z. J. Med.,1982, 12, pp. 10–13.Aortic root abnormalities including cusp thickening, subvalvular stenosis, and mild aortic root dilatation are the most common cardiac complications in patients with long standing ankylosing spondylitis (AS). Twenty‐three patients with definite idiopathic AS (New York Criteria 1966) and twenty‐two matched controls were studied with M‐mode echocardiography. Only one of the AS patients had clinical aortic incompetence. Six of the AS patients had mildly dilated aortic roots (normal<3–7 cm) with a mean diameter of 3–9 cm (range 38 to 4‐ 00 cm). None of the twenty‐two controls matched for age, sex and blood pressure had dilated aortic roots, with a mean diameter of 3‐3 cm (range 2–9 to 3–6 cm).No correlation existed between aortic dilatation and severity of disease estimated by acute phase proteins–caerulo plasmin, alpha 1‐antitrypsin, alpha 1 acid glycoprotein, ferritin and C Reactive protein.Contrary to a previous report, mild aortic root dilatation occurs in long standing cases of AS. Although it is a non‐specific finding, it does not appear to be related to age or blood pressure and may therefore be the foreru