Some images worth learning from are posted here
Balloon pulmonary angioplasty - Reperfusion injury
Factors associated with reperfusion injury after balloon pulmonary artery balloon angiolasty are
(1) Increase in diameter >70%
(2) Increase in PA pressure >170%
(3) Distal mean PA pressure > 20 mmHg
From Arnold LW et al. AJC 1988;62:327-330.