A patient in their 70s underwent aortic valve replacement with a biological prosthesis for severe aortic stenosis. Their postoperative course was complicated with recurring pericardial and pleural effusions that were managed by colchicine and repeated pericardiocenteses and pleurocenteses. The patient was initially discharged from the cardiac surgery ward and transferred to a cardiology ward on the 45th postoperative day. Two days after the transfer, pericardiocentesis was attempted by a subxiphoid approach under fluoroscopic guidance. On visualization of bright red blood in the catheter, fluoroscopic imaging showed the tip of the pericardiocentesis catheter in the ascending aorta, with an initial puncture site in the wall of the right ventricle (Figure). The patient underwent surgical catheter extraction and was discharged home without complications, remaining asymptomatic during subsequent follow-up visits.1,2