CV System (Add. to what's in HA - Heart) Flashcards
What does heart rate variability refer to?
a.k.a RR variability
Variation in time interval between heartbeats.
Beat to beat interval
Where can you find the RR variability on an ECG?
Between the QRS of 1 beat and the QRS of another beat
What is meant by an inotropic action/effect?
When the beat strength of the heart ⬆️
What is meant by an chronotropic action/effect?
Change in the HR + rhythm
+ive chronotropes = ⬆️ HR
-ive = ⬇️ HR
What is high HR variability associated with?
+ive outcomes:
- Good emotional regulation
- Well being
- Good Info processing skills
What is low HR variability associated with?
-ive outcomes:
- Depression, anxiety - poor emotional reg
- IBS
- Ageing
- Cardiac mortality
What is VO2?
Diff between vol of gas inhales + vol of gas exhaled per unit of time.
What are the determinants of VO2
Bf + O2 extraction
Fick Equation
How is bp calculated?
CO X Total Peripheral Resistance
Why is there an increased extraction of O2 from the blood during exercise?
Due to the oxyhemoglobin dissociation curve
= A sigmoidal response
What affects haemoglobin O2 affinity?
Acidity
PCO2
2,3 biphosphoglcyerate
Temp
What happens to the affinity of Hb in acidosis?
Decreases == More O2 delivered to acidic sites
What happens to the affinity of Hb in rising PC02?
Decreases = The harder the tissue is working = the more O2 is released
What happens to the affinity of Hb in the presence of 2,3biphosphoglycerate formation during glycolysis?
Helps to unload O2 by binding w/ Hb
What happens to the affinity of Hb in increasing temps ?
Decreases
= More O2 delivered to warmer muscles
== In hypothermia = O2 remains bound to Hb
