Approximately 1/3 of patients with heart failure (HF) present with conduction disturbances, most commonly (in about 25% of HF patients) as a LBBB pattern.
This percentage is significantly higher than the estimated (1.5%) prevalence of LBBB in the general population.
LBBB can be permanent or, more rarely, related to heart rate - that is, appearing above a frequency threshold.
Many patients with intermittent LBBB develop a permanent conduction disturbance in the long term. Repolarization changes are common in patients with LBBB, thus interfering with interpretation of stress tests.
Non-invasive imaging is indicated to depict ischemia in symptomatic patients with non-diagnostic ECG.
LBBB is commonly associated with perfusion defects at the anteroseptal and apical walls.
Frequency-dependet LBBB can cause “reversible” defects mimicking an ischemic pattern.
