Echocardiogram by apical-subcostal protocol in prone position during invasive mechanical ventilation in cardiovascular intensive care unit oleh César Del Castillo, Fernando Verdugo, Franco Appiani, Francisca Yáñez, Camila Bontá, Carlos Torres-Herrera, Angela Garcia, Zorba Blázquez-Bermejo, Javier Castrodeza, Daniel Requena, Andreina Rodríguez, Arquimedes Silvio, Agustín Gatica, Arnulfo Begazo, Mario Alfaro