Cardiovascular System - Relationship between resting values of Heart rate, Stroke Volume and Cardiac Output

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Heart Rate - HR

  • Represents number of times heart ventricles beat in 1 min
  • Average resting heart rate is 70-72 beats per minute
  • Max = 220-Age
  • Bradycardia - Resting heart rate below 60 beats
    • High level of aerobic fitness
    • Due to hypertrophy - Increase in size/thickness of heart muscle wall

Stroke Volume - SV

  • Volume of blood ejected by heart ventricles per beat/Difference in volume of blood before and after each ventricle contraction
  • Average resting stroke volume is approx 70ml
  • End diastolic volume - EDV before contraction is the volume of blood left in ventricles at end of relaxation/filling stage of cardiac cycle
  • End systolic volume - ESV - After contraction - Volume of blood left in ventricles at end of Contraction/Emptying Stage
  • EDV - ESV = SV

Cardiac Output (Q)

  • Volume of blood ejected by heart ventricles in 1 Min
  • Q = SV x HR
  • Litres/min = ml/beat x bpm

Heart's Response to Exercise

Resting

SV - 60-80ml

HR - 70-72 bpm

Q - 5l/min

Sub - maximal

SV - 80/100ml - Untrained

  •  
    • 160/200ml - Trained

HR - 100-130bpm

Q - Up to 10l/min

Maximal

SV - 100-120ml Untrained

160-200ml - Trained

HR…

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