4. Heart failure

Question 1

cardiac output in typically healthy adult?

Answer 1

5L/min

Question 2

what does CO varies in response to?

Answer 2

both physiological and pathological factors

• preload – filling pressure
• afterload – “load” that ventricle must eject blood against
• contractility
• heart rate

Question 3

define Heart failure

Answer 3

Abnormality in cardiac function which is responsible for the failure of the heart to pump blood at
a rate commensurate with the requirements of metabolising tissues

Question 4

symptoms of heart failure?

Answer 4

Characterised by symptoms that may present and often in later stages of heart failure
- exercise intolerance, dyspnoea, fatigue (swelling)

Question 5

What is the self perpetuating spiral of heart failure

Answer 5

The physiological neruohormonal response attempts to compensate but will eventually lead to further pathology

compromised cardiac function → low Bp → baroreceptor → increase symp outflow:
• activate beta adrenoceptors → increases rennin → increased RAAS
→ increased aldosterone → increased preload,
→ vasoconstriction → increased afterload
• vasoconstriction → increased afterload

→ increased myocardial 02 demand → worse heart failure

Question 6

What is the management of heart failure

Answer 6

• Usually dealing with LV systolic dysfunction associated with reduced LV ejection fraction (<45%)
• Correct underlying cause (replace valve, angioplasty)
• Non pharmacological management – ↓↓salt intake, liquid reduction ~ 1.5L
• Addition of diuretic plus other therapeutic agents

Question 7

Aims of treating heart failure?

Answer 7

• reduction in symptoms (dyspnoea, fatigue, oedema)
• managed increase in exercise tolerance
• address arrhythmias, hyperlipidaemia, diabetes
• increase quality of life and slow morbidity

Question 8

What is the management for heart filaure with reduced ejection fraction?

Answer 8

1. diuretics for symptom relief (furosemide)
2. ACEi (lisinopril, ramipril) and BB (bisopralol)
3. MRA (spironolactone) if symptoms continue
   • ARB if intolerent to ACEi (candesartan, losartan)

Question 9

function of diuretic in heart failure treatment?

Answer 9

1 Reduce signs of volume overload –dyspnoea and peripheral oedema

Question 10

function of ACEi, ARB and MRA in heart failure treatment?

Answer 10

Reduce sympathetic output, vasodilation, reduce sodium and water retention and increase bradykinin

Question 11

function of beta blockers in heart failure treatment?

Answer 11

Reduce remodelling and improve systolic function

Question 12

overall function of treating heart failure?

Answer 12

decrease preload and afterload improving cardiac output

Question 13

what may occur in some individuals prescribed spironolactone?

Answer 13

• In some individuals refractory hyperaldosteronism occurs (excessive RAAS activity, sometimes
called aldosterone escape) in spite of ACEi/ARB
• Spironolactone given as an adjunct to ACEi/ARB + diuretic

Question 14

How do you remember secondary prevention of MI?

Answer 14

BADS

Beta blockers
Acei or ARBs
Dual anti platelet therapy
Statin

Question 15

How do you remember acute treatment of MI?

Answer 15

MONA

Morphine
Oxygen
Nitrates
Aspirin