In-hospital Cardiopulmonary Resuscitation With Balloon Occlusion of the Descending Aorta

This study will test if a sustained Return of Spontaneous Circulation (ROSC) in patients with cardiac arrest is more frequent when patients receive advanced cardiac life support (ACLS) alone or when they receive ACLS plus a balloon occlusion of the thoracic aorta.

Inclusion criteria: * patients suffering from in hospital cardiac arrest (IHCA), including patients with out of hospital cardiac arrest (OHCA) and return of spontaneous circulation (ROSC), transported to the emergency department, where they suffer a second arrest (IHCA) * successful placement of a femoral artery introducer sheath * any electrical cardiac activity seen in the initial rhythm analysis * ongoing effort of resuscitation as determined by study-independent resuscitation lead Exclusion criteria: * IHCA in the operating room, on intensive care unit or in the cardiac catheter laboratory * hospital visitors suffering from cardiac arrest * asystole seen in the initial rhythm analysis * (presumed) age under 18 years * known "do not resuscitate"-order * known or obvious pregnancy * traumatic cardiac arrest * known aortic pathologies that render cannulation impossible * known allergies to radiographic contrast agents