- Impaired cardiac function including any of the following: LVEF by echocardiography < 45% or below the institutional lower range (whichever is greater); complete left bundle branch block; long QT syndrome or family history of; history or presence of significant ventricular or atrial tachyarrhythmias; clinically significant brachycardia (< 50 bpm); QTcF > 450 msec at baseline; right bundle branch block plus left anterior hemiblock; bifascicular block; myocardial infarction ≤ 12 months; uncontrolled angina; other clinically significant heart disease (e.g., congestive heart failure)