Could this intermittent prominent anterior force be a septal fascicle block?

Abstract

Background

A septal fascicle of the left bundle branch is an anatomical variant present in a substantial number of human hearts. However, the electrocardiographic features of its block remain controversial.

Case summary

We describe a case of transitory prominent anterior forces consistent with an intermittent left septal fascicle block, identified on a preoperative ECG of an adult male with a history of diabetes mellitus and systemic hypertension.

Conclusion

Clinicians should recognize septal fascicular block as an emerging and underrecognized cause of a prominent R-wave in the right precordial leads, particularly when the pattern is intermittent.