Unusual case of coronary perforation which developed delayed cardiac tamponade due to collateral flow from contralateral coronary artery.

Coronary artery perforation is a rare but catastrophic complication of percutaneous coronary intervention (PCI). PCI for chronic total occlusion (CTO) lesions is associated with lower procedural success rate and higher incidence of complications as compared with non-CTO coronary vessels. Here we report a rare case of a patient who developed coronary perforation during PCI for the CTO lesion and suffered from delayed cardiac tamponade due to collateral flow from the contralateral coronary artery despite complete hemostasis of the perforated site by the covered stent.