Cardiovascular Collapse During Transcatheter Aortic Valve Replacement: Diagnosis and Treatment of the "Perilous Pentad".

Transcatheter aortic valve replacement (TAVR) has, without a doubt, brought an unprecedented excitement to the field of interventional cardiology. The avoidance of a sternotomy by transfemoral or transapical aortic-valve implantation appears to come at the price of some serious complications, including an increased risk of embolic stroke and paravalvular leakage. The technical challenges of the procedure and the complex nature of the high-risk patient cohort make the learning curve for this procedure a steep one, with the potential for unexpected complications always looming. Although most commonly relating to vascular access, these complications can also result from prosthesis-related trauma or malposition, or from unanticipated trauma from the pacing wire or the super stiff wire. Sudden and unexplained hypotension is often the earliest indicator of major complication and must prompt an immediate and detailed exclusion of five major pathologies: retroperitoneal bleeding from access site rupture, aortic dissection or rupture, pericardial tamponade, coronary ostial obstruction, or acute severe aortic regurgitation. In most cases, these can be dealt with quickly, and by percutaneous means, although open surgery may occasionally be necessary. Increased operator and team experience should make prevention and recognition of these catastrophic complications more complete. For this reason, the importance of specific training, such as that provided by the valve manufacturers through workshops and proctorship, cannot be overemphasized. It is essential that all operators, and indeed all members of the implant team, exert extreme vigilance to the development of intraprocedural complications, which could have rapid and potentially lethal consequences. Greater experience with an improved understanding of these risks, along with the development of better devices, deliverable through smaller and less traumatic sheath technology, will undoubtedly improve the safety and, potentially, widen the applicability of TAVR in the future. Forthcoming innovations include a newer generation of the valves with operator-controlled steerability to facilitate negotiation of tortuous aortic anatomy, as well as fully retrievable and resheathable devices to accommodate the events of dislocation or embolization. The fact that Transcatheter aortic valve implantation (TAVI) is new implies learning from experience but also from mistakes. The TAVI team must be vigilant to recognize and diagnose intraprocedure severe hypotension. The "perilous pentad" of catastrophic causes must be constantly borne in mind: retroperitoneal bleeding from access site rupture, aortic dissection or rupture, pericardial tamponade, coronary ostial obstruction, and acute severe aortic insufficiency.