Heart Failure

Question 1

What is heart failure

Answer 1

Inability of the heart to meet the demands of the body

A clinical syndrome of reduced cardiac output, tissue hypoperfusion, increased pulmonary pressure and tissue congestion

Question 2

What allows to heart to work as an effective pump

Answer 2

Functioning muscle

Correct chamber size

One-way valves

Question 3

Name some conditions that cause heart failure (aetiology of HF)

Answer 3

IHD/coronary heart disease - myocardial dysfunction

Hypertension - increase afterload

Aortic stenosis - increase afterload

Other valvular or myocardial structural diseases

Cardiomyopathies

Arrhythmias

Pericardial diseases

Question 4

How do we measure the volume pumped out of the ventricle per minute

Answer 4

CO = SV x HR

Question 5

What factors influence stroke volume and are they positive or negative influences

Answer 5

Pre-load - positive

Myocardial contracility - positive

After-load - negative

Question 6

What causes the stroke volume to be reduced

Answer 6

Reduced pre-load - impaired filling during diastole

Reduced myocardial contractility

Increased afterload - this usually affects pre-load and/or myocardial contractility

Question 7

What are the two main types of problems and which part of the heart cycle do they affect

Answer 7

Filling problem - diastole

Contractility/ejection problem - systole

Question 8

What are the two main classifications of heart failure

Answer 8

HFrEF - heart failure with reduced ejection fraction, systolic dysfunction

HFpEF - heart failure with preserved ejection fraction, diastolic dysfunction

Question 9

What is the ejection fraction and how is it measured

Answer 9

It is amount of blood pumped out of the ventricle divided by total amount of blood in ventricle

Measured on echocardiogram

Question 10

When is an ejection fraction said to be reduced

Answer 10

When it is <40%

Question 11

Why are heart failures cuased by a filling problem said to be preserved

Answer 11

Ventricle ejects less volume but there is is less volume to begin with, so the fraction of what is available to eject is still >50% so the ejection fraction is preserved

Question 12

What is cor pulmonale

Answer 12

Isolated RV heart failure secondary to chronic lung disease

Question 13

What is the term for when a patient has isolated RV heart failure secondary to chronic lung disease

Answer 13

Cor pulmonale

Question 14

What physiological mechanisms are activated by the drop in cardiac output and what activates them

Answer 14

Increased sympathetic drive activated by baroreceptors

Activation of the RAAS pathway by decreased renal perfusion

Question 15

What overall effect does the activation of the compensatory mechanisms have on the heart

Answer 15

Increased sympathetic drive increases afterload

Activation of the RAAS pathway increases preload and afterload

Both of these systems increase the cardiac work, overworking the heart further

Question 16

What are the clinical signs and symptoms of heart failure

Answer 16

Fatigue/lethargy

Breathlessness

With or without leg swelling - both legs affected!

Pitting oedema in peripheral tissues

Pulmonary Oedema

Question 17

What are the symptoms of LV heart failure

Answer 17

Fatigue/lethargy

Breathlessness - exertional

Orthopnoea

Paroxysmal nocturnal dysnoea

Basal pulmonary crackles

Cardiomegaly - displaced apex beat

Question 18

What are the symptoms of RV heart failure

Answer 18

Fatigue/lethargy

Breathlessness

Peripheral pitting oedema

Raised jugular venous pressure

Tender, smooth enlarged liver

Question 19

What investigations and examinations are done to test for heart failure

Answer 19

FBC - anaemia can cause symptoms of heart failure

Electrolytes and renal function - chronic kidney failure can cause fluid overload and HF symptoms

Glucose/HbA1c

Lipid profile

BNP - elevated BNP suggests heart failure, normal BNP with breathlessness usually excludes HF

ECG - abnormal ECG and elevated BNP suggests HF

Chest X-ray - pulmonary oedema

Echocardiogram - measure EDV

Question 20

What is the treatment of acute heart failure

Answer 20

Oxygen - CPAP

Intravenous loop diuretics - furosemide

Herapin to prevent DVT

Possibly need IV nitrates to reduce preload with/without coronary vasodilation

Question 21

How do you manage heart failure long term

Answer 21

Correct underlying cause - intervention, implantable device

Non-pharmacological measures (lifestyle changes)

Pharmacological therapy - symptomatic improvement, delay progression of HF, reduce mortality. E.g. ARBs, ACEi, beta-blocker, spironolactone

Treat complications/associated conditions/cardiovascular risk factors

Question 22

Which two neuro-hormonal systems are targeted in drug therapy of HF

Answer 22

SNS

RAAS

Question 23

What are the compensatory mechanisms done by the SNS

Answer 23

Increase cardiac contractility

Arterial and venous vasoconstriction

Tachycardia

Question 24

What are the deleterious effects of the SNS being stimulated long term

Answer 24

Beta-adrenergic receptors are downregulated

Noradrenaline induces cardiac hypertrophy/myocyte apoptosis and necrosis via alpha-receptors

NA induces upregulation of RAAS

Reduced heart rate variability

Question 25

How do beta-blockers work

Answer 25

Reduce heart rate

Reduce BP

Reduced BP and HR reduces myocardial oxygen demand

Reduce mobilisation of glycogen

Negate unwanted effects of catecholamines

Question 26

How should beta-blockers be given to a patient

Answer 26

Administered once patient is stable

Start at a low dose and titrate slowly, increasing dose

Question 27

What do you use to treat the RAAS

Answer 27

ACE inhibitors

Angiotensin receptor blockers

Question 28

What might management of HF include

Answer 28

Pharmacological - ACE, B-blockers, spironolactone

Intervention - treat underlying disease, heart transplant, mechanical assist devices

Implantable pacemakers - biventricular pacing

Implantable defibrillators

Lifestyle modifications - Reduce salt, alcohol and BP, increase aerobic exercise