The present study is an International multicentric prospective observational cohort study. This will be an international research campaign to prospectively collect and analyze clinical data of all VA ECLS patients admitted to participating ICUs with a focus on LV venting modalities. The aims of the study are: * To investigate the meaning of LV overload during veno-arterial (VA) extracorporeal life support; * To extensively describe the left ventricular (LV) unloading strategy during VA extracorporeal life support in a large prospective international cohort. * To compare different strategies to unload the left ventricular in terms of efficacy and outcomes;