Ikram, H., Banim, S. O., and Makey, A. R. (1974). Thorax , 29 , 204-208. Clinical features of non-tuberculous constrictive pericarditis. This paper describes the clinical features of five cases of constrictive pericarditis of non-tuberculous aetiology. The findings in this syndrome are compared with those in tuberculous constrictive pericarditis. The non-tuberculous variety had a short history, and absence of ascites and third heart sounds. Pericardial calcification, paradoxical arterial pulse, and the marked `y9 descent in the venous pulse were absent in contrast to tuberculous constriction. An atrial sound was usual and the chief venous wave was the `a9 wave. The difficulty in diagnosing this type of pericardial constriction and its differentiation from `restrictive9 cardiomyopathy is discussed. It is suggested that all currently available diagnostic techniques are liable to failure and, if in doubt, a diagnostic thoracotomy is mandatory.