If the QRS complex is widened and downwardly deflected in lead V1, a left bundle branch block is present ... The ECG strip below shows normal sinus rhythm, then atrial fibrillation with a rapid ...

In addition, information can be gleaned from irregularities (e.g., premature atrial contractions [PACs], premature ventricular contractions [PVCs], intermittent bundle branch block, or changes in ...

Normal sinus rhythm 3rd degree AV block (complete heart block) Right bundle branch block Left anterior fascicular block Note that the combination of a right bundle branch block and a left anterior ...