Cardiac Considerations

1
Cardiac Considerations

• Draw and label a diagram of the heart
• Explain the cardiac cycle
• Describe how the heart works
• Discuss heart regulation at rest and during
  exercise
• Discuss cardiac dynamics

2
The Heart

• Function
• To provide the pumping action and force for
  blood transportation around the vascular system

3
The Heart

• Myocardium - Cardiac Muscle
• Four Chambers
• Two Upper - Atria
• Two Lower - Ventricles

4
The Heart

• Blood flows into the upper chambers via three
  veins
• Vena Cava
• Superior Inferior
• Pulmonary Vein

5
The Heart

• As the Atria contract blood is pushed through two
  valves
• Tricuspid Valve - Right side of heart
• Bicuspid (Mitral) Valve - left side of heart

6
The Heart

• The blood passes through the valves into the
  ventricles. The atria relax and the valves close.

7
The Heart

• The ventricles then contract and the blood is
  then transported away from the heart via two
  arteries
• Aorta
• Pulmonary Artery

8
The Heart Beat

• Sinoatrial (SA) Node
• Atrioventricular (AV) Node
• AV bundle ( Bundle of His)
• Purkinje Fibres

9
Control of the Heart Beat

• The Parasympathetic Nervous System
• Decreases HR
• Sympathetic Nervous System
• Increases HR Contraction force
• The Endocrine System (release of hormones)
• Increases HR Contraction Force

10
The ElectroCardioGram

• P Wave
• Atrial Depolarisation
• QRS Complex
• Ventricular Depolarisation
• T Wave
• Ventricular Depolariastion

11
The Cardiac Cycle

• Systole
• Contraction phase
• Diastole
• Relaxation phase

12
Cardiac Dynamics

• Heart Rate (HR)
• The number of heart beats measured in a minute
• Stroke Volume (SV)
• The amount of blood ejected from the left
  ventricle in a single contraction
• Cardiac output (Q)
• The amount of blood ejected from the left
  ventricle in a minute (SV x HR)

13
Independent Learning Session

• Using the Biopac package
• Conduct and record an ECG
• Annotate the ECG by identifying
• The PQRST
• Atrial and Ventricle systole diastole