Dilation of the septal collateral artery and subsequent cardiac tamponade during retrograde percutaneous coronary intervention using a microcatheter for chronic total occlusion.

Microcatheters are often used for percutaneous coronary intervention via the retrograde approach through a collateral channel for chronic total occlusion lesions. Recently, we encountered an alarming case in which a septal collateral artery was dilated after the removal of a microcatheter. This dilated septal artery ruptured spontaneously and resulted in a cardiac tamponade, which was successfully treated by pericardiocentesis and coil embolization.