- Complete LBBB
- QRS duration ≥120 ms
- Broad notched or slurred R wave in lateral leads (I, aVL, V5, and V6) and an occasional RS pattern in V5 and V6 attributed to displaced transition of QRS complex
- Absent Q waves in leads I, V5, and V6, but in the lead aVL, a narrow Q wave may be present in the absence of myocardial pathology
- R peak time >60 ms in leads V5 and V6 but normal in leads V1, V2, and V3, when small initial R waves can be discerned in the precordial leads
- ST and T waves usually opposite in direction to QRS
- Incomplete LBBB
- QRS duration between 110-119 ms
- LVH pattern
- R peak time >60 ms in leads V4, V5, and V6
- Absence of Q wave in leads I, V5, and V6