Table 1.

Classification of purulent pericarditis according to source of infecting organism

I	Infection by contiguous spread from a pleural, mediastinal or pulmonary focus
II	Infection by contiguous spread of intracardiac infection
III	Infection following systemic bacteraemia
IV	Infection with contiguous spread from a postoperative infection
V	Infection following a subdiaphragmatic suppurative lesion