Reappraisal of ECG Lead V1 in the Assessment of Cardiac Resynchronization

Current research on the relevance of electrocardiography in cardiac resynchronization therapy

“…However several studies have shown that dominant R can be present in isolated RV pacing, and that it may be absent in case of non-apical RV pacing. Barold [6] has summarized the data regarding the utility as well as the controversy regarding lead V1 in a recent editorial. Besides the lead related issues as mentioned above, absence of R wave in lead V1 despite biventricular pacing can happen due to regional exit blocks (with or without latency) around the lead target area as well as generalized conduction disturbances and placement of the lead in middle cardiac vein or anterior veins.…”