“…Although five previous cases of pulmonary artery perforation have been reported (Chun and Ellestad, 1971;Lapin et al, 1972;German et al, 1973;Golden et al, 1973;Page et al, 1974), the factors involved in these perforations by balloontipped catheters are unclear. Several predisposing factors have been emphasised; pulmonary hypertension (German et al, 1973), an excessively peripheral location of the catheter (Chun and Ellestad, 1971), a large loop of catheter in the right atrium or right ventricle which may allow the tip to perforate the pulmonary wall secondary to catheter motion (Chun and Ellestad, 1971), and anticoagulation (Golden et al, 1973).…”