The Washington manual of echocardiography [electronic resource] / editor, Nishath Quader, MD, FACC, FASE, Assistant Professor of Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri ; associate editors, Majesh Makan, MD, FACC, FASE, Associate Professor of Medicine, Associate Director of Echocardiography, Division of Cardiology, Washington University School of Medicine, St. Louis, Missouri, Julio E. Pérez, MD, FACC, FASE, FACP, FAHA, Professor of Medicine, Director of Echocardiography, Cardiovascular Division, Barnes-Jewish Hospital, Washington University School of Medicine, St. Louis, Missouri