Congestive heart failure

Question 1

Definition of heart failure (HF)

Answer 1

Inability of the heart to pump adequate amount of blood (reduced cardiac output) to meet the metabolic demands of the body

Question 2

What are the features of heart failure

Answer 2

Reduced cardiac output, reduced tissue perfusion, reduced contraction/preload and odema

Question 3

Pathophysiology of heart failure

Answer 3

1. Weak heart won’t be able to pump enough blood to organs. due to clogged arteries or increased blood pressure.
2. SV (volume of blood pumped per beat) reduced & so cardiac output (volume of blood pumped per minute) is also reduced
3. Heart’s compensatory mechanisms are activated:

• increased heart rate (reduced filling)
• structure increases in size (ventricles dilate = dilated cardiomyopathy) but this means it looses its ability to pump well =sv reduced even further or hypertrophic (thick walls) but this makes it stiff since less room is available for blood
• reduced perfusion of kidneys activated RAAS (to release renin, aldosterone to retain water and salt) = volume overload

Question 4

Explain the effects of the sympathetic nervous system in heart failure (compensatory mechanism)