Ischaemic Heart Disease

Overview of the arterial supply of the heart. LCS 》 LCA 》 CA 》 LAD 》 Diagonal, 1st / 2nd obtuse marginal branches. RCS 》 RCA 》 RMA 》 PDA. Also has sinuatrial branch, and AV nodal branches.

Some general important points to consider:

• Usually the RCA is dominant, as it gives rise to PDA. It also usually supplies the SA node, and AV node – the conduction “headquarters” of the heart.

• These arteries usually lie in the epicardial fat (sending penetrating branches to supply muscle), thus making this region the highest blood supplied area. The subendocardial region tends to receive the lowest blood supply. The apex is the furthest away from the aorta, thus the subendocardial region of the apex of the heart receives the lowest blood supply.

• Coronary flow for LV only occurs during diastole due to high filling pressures, whilst flow for RV occurs during both systole + diastole. This explains why LV is infracted more often than RV (i.e.: RV has better blood supply).

Category: Pathology Notes