- Presence of electrocardiographic or other abnormalities that interfere with ECG interpretation or may cause a false positive stress test (e.g., ≥ 1 mm horizontal or down-sloping ST segment depression at rest in any standard ECG lead, Lown-Ganong-Levine syndrome, Wolff-Parkinson-White syndrome, left bundle branch block, left ventricular hypertrophy with repolarization abnormality, ventricular pacemaker, etc.)