Step I Ejection time

[OrthoRehab33]

Can someone please explain ejection time! Why do nitrates cause decreased ejection time and why does Beta blockers increase it?

 

[Jabbed]

Can someone please explain ejection time! Why do nitrates cause decreased ejection time and why does Beta blockers increase it?

Nitrates: ↓venous return → ↓EDV → ↓SV → ↓ejection time
Beta blockers: ↑vascular resistance (ß2 vascular receptors) → ↑afterload → ↑ejection time

 

[OrthoRehab33]

Nitrates: ↓venous return → ↓EDV → ↓SV → ↓ejection time
Beta blockers: ↑vascular resistance (ß2 vascular receptors) → ↑afterload → ↑ejection time

I thought BB decrease afterload by inhibiting B1 on Juxaglomerular appratus from releasing renin (no AT2= no vasoconstriction).

 

[Jabbed]

I thought BB decrease afterload by inhibiting B1 on Juxaglomerular appratus from releasing renin (no AT2= no vasoconstriction).

That's a short term phenomenon. AT2 levels are back to normal within a few weeks. (Then again, AT2 levels go back to reference range even with ACE-I in the same span of time, so who really knows.)

Sent from my trltetmo using SDN mobile

 

[OrthoRehab33]

That's a short term phenomenon. AT2 levels are back to normal within a few weeks. (Then again, AT2 levels go back to reference range even with ACE-I in the same span of time, so who really knows.)

Sent from my trltetmo using SDN mobile

Gotcha, thanks!

 

[hsk013]

Nitrates: ↓venous return → ↓EDV → ↓SV → ↓ejection time
Beta blockers: ↑vascular resistance (ß2 vascular receptors) → ↑afterload → ↑ejection time

↑vascular resistance (ß2 vascular receptors) is only in the beginning right?
"Cardiodepression initially evokes a proportional rise in vascular resistance"??? But over the long run, it should lower blood pressure by lowering vascular resistance?