The presence of bifascicular block and worsening AV block with increasing heart rates should raise the suspicion of infranodal Wenckebach with the attendant risk of progression to complete heart block.
When type 1 AV block occurs with bifascicular block, however, the risk of progression to complete heart block is significantly increased because of probable infranodal disease.
complete atrialventricular block, second degree Mobitz II atria l-ventricular block), bifascicular
block, congestive heart failure, ischemic heart disease, left ventricular hypertrophy, and valvulopathy (1, 2).
The electrocardiogram was unchanged from prior examinations with a bifascicular
block, but no QT prolongation.
A recent study investigated the prognosis and SCD risk in a cohort of 100 patients with bifascicular block.
Long-term prognosis in patients with bifascicular block--the predictive value of noninvasive and invasive assessment.
Isolated new block in only one of the three fascicles even with P-R prolongation, and preexisting bifascicular
block and normal P-R interval poses somewhat less risk: these patients should be monitored closely, with insertion of a temporary PM deferred unless higher degree AV block occurs.