Echocardiography / Prospective studies / Humans / Left Ventricular Assist Device / Female / Male / Left Ventricular Dysfunction / Real Time / Aged / Middle Aged / Cardiac Arrhythmias / Myocardial Infarction / Adult / Public health systems and services research / Indexation / Heart Ventricles / Predictive value of tests / The American / Male / Left Ventricular Dysfunction / Real Time / Aged / Middle Aged / Cardiac Arrhythmias / Myocardial Infarction / Adult / Public health systems and services research / Indexation / Heart Ventricles / Predictive value of tests / The American