Assuming cardiac tamponade has been excluded (procedure-guided TOE or focused TTE), we would proceed with advanced mechanical circulatory support (MCS). This aims to maintain blood flow and oxygen delivery to dependent organ systems, thereby preventing multiple organ dysfunction and subsequent death, whilst the underlying cause for critical deterioration is reversed. A minimal flow rate of 70 mL/kg body weight per minute (cardiac index >2.5 L/m²) is generally required to provide adequate organ perfusion, equalling the sum of MCS output and the remaining intrinsic cardiac output. A range of potential methods is available; however, where active cardiopulmonary resuscitation is underway in the catheterisation laboratory, rapid percutaneous institution of venoarterial extracorporeal membrane oxygenation (ECMO) is a valuable treatment option3,4. As this patient is already instrumented in preparation for TAVI, cardiopulmonary bypass can be rapidly instituted using standard techniques4. Compact, portable devices with rapid initiation and easy manipulation are key in this setting5-7; however, the best device is the one with which the team are most familiar. The aim is to provide respiratory and/or circulatory support allowing for either surgical aortic valve replacement or TAVI. Parental direct thrombin inhibitors may be used for anticoagulation in the presence of heparin-induced thrombocytopaenia on ECMO7,8 resulting in a dose-dependent increase in activated partial thromboplastin time allowing for simple monitoring9. Additional care must be taken to avoid downward displacement of the TAVI, and/or thrombosis of the implanted valve during extracorporeal support due to absence of left ventricular ejection/aortic valve opening.
Publication information
How should I treat a cardiac arrest during transcatheter aortic valve implantation? Leroux L1, Seguy B, Labrousse L, Casassus F, Dijos M, Dos-Santos P, Lange R, Bleiziffer S, Vranckx P, Price S. EuroIntervention 2014 Mar 13. pii: 20120907e. [Epub ahead of print]