Anatomy Question: Right-, Left-, Co-dominant circulation

[awkko]

Hi all,

I'm having issues on "deciding what source to trust." The topic is left-, right-, and co-dominant circulation. Also, I'm a bit confused as to where the AV nodal artery, SA nodal artery, and PDA originate from.

Question #1: What determines right-/left-/co-dominant circulation? Is it the PDA, or the AV Nodal Artery? Some sources (Lilly's Pathophysiology of Heart Disease 6E, USMLE First Aid 2017) say it's the PDA. In other words, if the PDA comes from the RCA --> right dominant, vice versa. Other sources (Netter's Anatomy, Wikipedia - I know ) say it's the AV Nodal Artery that determines dominance.

Question #2: If an individual is right dominant, does that mean ALL of the following: AV nodal artery, SA nodal artery, and PDA originate from the RCA? Or, can it be possible that, even if an individual is right dominant, that an SA nodal artery could still arise from the LCA?

Thanks in advance!!

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[Militarydoc1]

1. PDA+/-PL determines dominance. Codominance exists when both RCA and LCX supply the posterior/inferior wall i.e PDA off RCA and PL off LCx
2. No

 

[awkko]

1. PDA+/-PL determines dominance. Codominance exists when both RCA and LCX supply the posterior/inferior wall i.e PDA off RCA and PL off LCx
2. No

For #2, is it possible for a right dominant circulation individual to have RCA --> PDA, but LCX --> AV nodal artery?