Background: Atypical right bundle branch block (RBBB) may present with an rS pattern and notched S wave in lead V1 . The notched S wave may represent slowed conduction or delayed activation of the right ventricular conduction system or ventricular myocardium.
Methods: We retrospectively analyzed the QRS patterns in accessory right precordial leads (from V3 R to V5 R) in 15 adults/senior individuals with notched S wave in lead V1 .
Results: In the right accessory precordial leads, 13 showed triphasic QRS pattern with final R' wave in their QRS complexes. This QRS pattern in association with notched S wave in lead V1 is suggestive of the presence of RBBB (incomplete or complete).
Conclusions: A notched S wave in lead V1 and in the right precordial accessory leads associated with a final R' wave suggests the possibility of concealed RBBB (incomplete or complete).
Keywords: notched S wave in V1; right bundle branch block; right precordial accessory leads.
©2013 Wiley Periodicals, Inc.