Pitfalls
- Failing to recognise bifascicular block – make sure to look for LAFB or LPFB in all cases of RBBB8.
- Not recognising that new bifascicular block may be the only ECG change seen in patients with acute LAD occlusion.
- Ventricular tachycardia (VT) can present with a bifascicular pattern. When VT originates in the left ventricle near the LPF it will present with a RBBB/LAFB pattern. When VT originates in the left ventricle near the LAF it will present with a RBBB/LPFB pattern. Make sure the ECG shows a supraventricular rhythm with bifascicular block rather than VT with a bifascicular pattern.
- Atropine will not work for those patients who progress to episodes of trifascicular block (i.e. complete heart block) within the Emergency Department, as the block is below the AV node12. These patients will require pacing.