2. Schematic diagram of blood supply to cardiac conduction system. The first septal branch of the left anterior
descending (LAD) coronary artery supplies a critical portion of the interventricular conduction system (red
oval). AV, atrioventricular; marginal a., marginal artery; PDA, posterior descending artery; RCA, right
coronary artery; SA, sinoatrial. Reproduced, with permission, from Harthorne JW, Pohost. GM, Electrical
therapy of cardiac dysrhythmias. In Levine, HJ (ed) Clinical Cardiovascular Physiology, New York, Grune
and Stratton: 1976. pp. 853â882
3. Blood Supply to Bundle of Branches
LBBB RBBB
Anterosuperior fascicle Posteromedial fascicle
ď§ Both LAD and RCA
ď§ 50% By septal
branch of LAD and
AV node branch of
RCA
ď§ Other 50% by only
LAD
ď§ 50% Only by the AV
nodal branch of
RCA(Kugelâs artery)
ď§ Other 50% by AV nodal
branches of RCA
ď§ Septal branches of LAD
Both LAD and RCA
50% By septal branch
of LAD and AV node
branch of RCA
Other 50% by only
LAD