Cardiac failure refers to the heart's inability to pump enough blood to meet metabolic demands. It can be classified in several ways, including based on severity, the side of heart involved, cardiac output level, duration, and type of function affected. Compensated heart failure involves mechanisms that return cardiac output to normal levels, while decompensated failure results in fluid retention and pulmonary or peripheral edema as compensatory mechanisms fail. Ejection fraction is normally over 50% and remains relatively normal in diastolic heart failure.

1. Cardiac Failure
Prof. Dr. Rashid Mahmood

2. Lesson Contents
• Dynamics of the Circulation in Cardiac Failure
• Unilateral Left Heart Failure
• Low-Output Cardiac Failure-Cardiogenic Shock
• Edema in Patients with Cardiac Failure
• Cardiac Reserve

3. Definition:
• The term cardiac failure means that the heart
is unable to pump sufficient blood to satisfy
the metabolic demands.
• That results in under-perfusion which causes
fluid retention and increased blood volume

4. Types (Classifications of Cardiac Failure)
1. Based on stage/severity/ compensation
1. Compensated
2. Decompensated
2. Based on side of heart involved
1. Left heart failure
2. Right heart failure
3. Bilateral heart failure
3. Based on cardiac output
1. Low-output cardiac failure
2. High-output cardiac failure
4. Based on duration
1. Acute heart failure
2. Chronic heart failure
5. Based on type of function affected
1. Systolic heart failure
2. Diastolic heart failure

5. Acute Effects of Moderate Cardiac Failure
Cardiac Failure
↓cardiac output damming of blood
in the veins
↑ increased venous
pressure

6. Compensation
Compensatory
Mechanisms
Chemo-
receptor
reflex,
CNS
ischemic
response
Sympathetic
Nervous
Reflexes
Baro-
receptor
reflex
↑tone of blood vessels
↑mean systemic filling
pressure

7. Chronic Stage of Failure
Fluid Retention
Moderate Fluid
Retention
Excess Fluid
Retention
Beneficial Detrimental Effects
overstretching of heart pulmonary edema edema

8. Q.1
• Name any two compensatory mechanisms for
low cardiac output

9. 1. Cardiac Failure based on
stage/severity/ compensation
• Compensated
• Decompensated

10. Compensated Heart Failure
(1) instantaneous effect
of the cardiac damage;
(2) compensation by
the sympathetic
nervous system,
(3) chronic
compensations
resulting from partial
heart recovery and
renal retention of fluid
1 2 3

11. Compensated
heart failure:
shift of Frank-
Starling Curve
downwards and
to the right in a
failing heart

12. Progressive changes in cardiac output
after acute myocardial infarction
(Compensated Heart Failure)

13. Decompensated Heart Failure
(1)
progressive
retention of
more and
more fluid
(2) progressive
elevation of
the mean
systemic filling
pressure
(3) progressive
elevation of
the right atrial
pressure
(4)heart is so
overstretched
or so
edematous
that it cannot
pump even
moderate
quantities of
blood
(5) Complete
heart failure2 3 4 51

14. Decompensated heart disease showing progressive shift of the venous return
curve to the right as a result of continued fluid retention

15. Greatly depressed cardiac output that
indicates decompensated heart disease

16. Effect of digitalis in elevating cardiac output curve
leading to increased urine output and progressive shift
of venous return curve to left

17. Q.2
• How does sympathetic stimulation
compensate low cardiac output ?

18. 2. Cardiac Failure based on side of
heart involved
1. Left heart failure
2. Right heart failure
3. Bilateral heart failure

19. Unilateral heart failure
↑Mean pulmonary
filling pressure
Pulmonary edema
(Rapid)
↑Mean systemic
filling pressure
Peripheral edema
(Congestive
Cardiac Failure)
(Slow)
Left heart failure Right heart failure

22. Mechanism of Slow Peripheral edema
in Cardiac Failure
• Severe acute
cardiac failure
often causes a
fall in
peripheral
capillary
pressure
rather than a
rise

23. Causes of reduced renal output of
urine in heart failure
(Long-Term Fluid Retention )
a. Decreased glomerular filtration
b. Activation of the renin-angiotensin system and increased
reabsorption of water and salt by the renal tubules
c. Increased aldosterone secretion
d. Stimulation of ADH
e. Activation of sympathetic nervous system
i. Decreased glomerular filtration rate
ii.Increased reabsorption of salt and water
iii.Stimulation of renin release and angiotensin II formation
iv.Stimulation of ADH

24. Cardiac Reserve
• The maximum percentage that the cardiac
output can increase above normal
• 300 to 400 percent
– In athletically trained person 500 to 600 percent
or more
– It decreases with all type of heart failure

25. Cardiac Reserve in different conditions

26. Q.3
• Define cardiac reserve.

27. 3. Cardiac Failure based on cardiac
output
1. Low-output cardiac failure
1. Ischemic heart disease
2. Cardiomyopathies
2. High-output cardiac failure

28. Low-Output
Cardiac
Failure-
Cardiogenic
Shock
Vicious Circle
of Cardiac
Deterioration
in Cardiogenic
Shock

29. High Cardiac output conditions

30. 4. Cardiac Failure based on duration
1. Acute heart failure
1. Left heart failure
2. Myocardial infraction
2. Chronic heart failure
1. Congestive heart failure

31. 5. Cardiac Failure based on type of
Function affected
Systolic heart failure
• Weak ventricular
contraction
• ↓ stroke volume
• ↓ ejection fraction
Diastolic heart failure
• ↓ elasticity of myocardium
• ↓ filling during diastole
• Ejection fraction initially
maintain
• Heart failure with preserved
ejection fraction

32. Q.4
• How much is normal ejection fraction?
• In which type of heart failure it is relatively
normal?

33. Take Home points (1/3)
• Inability of the heart to pump sufficient blood to
satisfy the metabolic demands is called cardiac
failure (Heart Failure)
• There are diffident Types of Classifications of
Cardiac Failure
• Cardiac Failure leads to ↑ increased venous
pressure and Fluid Retention
• Body Compensatory mechanisms may bring back
cardiac output to normal resting value
(Compensated Heart Failure), in mild to moderate
heart failure

34. Take Home points (2/3)
• Chronic Stage of Failure results in pulmonary
edema, peripheral edema, cardiac insufficiency.
• In Decompensated Heart Failure, homeostatic
mechanisms of the body are unable to bring back
the cardiac output to minimum normal value, and
the condition of the patients deteriorates, ending
in death, if not treated.
• Left heart failure leads to Pulmonary edema, that
may develop Rapidly.
• Right heart failure leads to Peripheral edema, that
develops Slowly. Right heart failure is commonly
called Congestive Cardiac Failure

35. Take Home points(3/3)
• Long-Term Fluid Retention due to compensatory
mechanisms are the major cause increased preload.
• Cardiac Reserve, i.e. the maximum percentage that
the cardiac output can increase above normal,
decreases in cardiac failure
• High- cardiac output conditions may ultimately lead
to cardiac failure
• Vicious Circle of Cardiac Deterioration results in
Cardiogenic Shock
• In Systolic heart failure there is ↓ ejection fraction
• In Diastolic Heart failure ejection fraction remains
preserved initially