Session 10 - Heart Failure

Question 1

What is the definition of heart failure?

Answer 1

Clinical syndrome of reduced cardiac output, tissue hypoperfusion, increased pulmonary pressures and tissue congestion

Question 2

What are 3 clinical signs of heart failure?

Answer 2

Dyspnoea
Fatigue
Tissue fluid retention

Question 3

What is the pathophysiology of heart failure?

Answer 3

Remodelling of cardiac muscle in response to other conditions changes ventricular function and shape/size impairs ventricular filling or emptying

Question 4

What are 2 main types of heart failure?

Answer 4

HFrEF - heart failure with reduced ejection fraction

HFpEF - heart failure with preserved ejection fraction

Question 5

What is end diastolic pressure?

Answer 5

How full the heart is filled up, higher volume = higher pressure

Question 6

How is cardiac output and end diastolic volume related?

Answer 6

Increasing end diastolic volume causes increased stretch which means greater stroke volume ejected in systole, therefore increasing cardiac output

Question 7

When heart failure becomes severe, how is the relationship between cardiac output and end diastolic volume affected?

Answer 7

Contractility is impaired, lowers force of contraction, when end diastolic volume increases, cardiac output falls

Question 8

How does a heart fail with preserved ejection fraction?

Answer 8

Ejection fraction preserved because end diastolic volume decreases and amt of blood pumped out decreases, ventricular chamber size is reduced

Question 9

What are 2 possible causes for heart filling problem?

Answer 9

Ventricular chambers too stiff

Ventricular walls thickened

Question 10

How does a heart fail with reduced ejection fraction?

Answer 10

Cannot pump with enough force (contraction problem), poor ventricular contraction so unable to empty it well

Question 11

What are 3 possible causes for heart failure with reduced ejection fraction?

Answer 11

Muscle walls thin or fibrosed
Chamber space enlarged
Abnormal or uncoordinated myocardial contraction

Question 12

What is the effect of neuro-hormonal activation on heart failure?

Answer 12

Leads to increased cardiac demand and further reduction in stroke volume

Question 13

What are 2 neurohumoral mechanisms activated by reduced blood pressure?

Answer 13

Baroreceptor detect and increases sympathetic drive

Kidneys detect lowered renal perfusion and activate renin-angiotensin-aldosterone pathway

Question 14

What are the 2 immediate effects of increased sympathetic drive and overall effect?

Answer 14

Increased heart rate and peripheral resistance, increasing afterlpad and hence increasing cardiac work

Question 15

What is the effect of activating renin-angiotensin-aldosterone (RAAS) pathway?

Answer 15

Increases circulating volume due to Na+ and water retention because of aldosterone and stimulated anti-diuretic hormone, increasing preload

Enhanced sympathetic activity and vasoconstriction increases afterload

Overall increased cardiac work

Question 16

How does pulmonary oedema occur on heart failure?

Answer 16

Increased LV pressure as failure to eject volume sufficiently, increases pressure in pulmonary circulation, increasing hydrostatic pressure at venule end of pulmonary capillary beds, nett force pushes fluid out into interstitial, increases volume of tissue fluid accumulates in pulmonary interstitial

Question 17

What are 4 symptoms of pulmonary oedema?

Answer 17

Breathlessness
Basal pulmonary crackles
Orthopnoea
Paroxysmal nocturnal dyspnoea

Question 18

How does peripheral oedema occur in heart failure?

Answer 18

Increased RV pressure as failure to eject, increase pressure in systemic venous circulation, increases central venous pressure and jugular venous pressure, increases hydrostatic pressure at venule end of capillary beds, increased volume of tissue fluid accumulates in interstitial

Question 19

What are 2 symptoms of peripheral oedema?

Answer 19

Bulging jugular vein

Lower limb pitting oedema

Question 20

What is the most common cause of RV failure?

Answer 20

LV failure

Question 21

What is congestive heart failure?

Answer 21

Both ventricles fail

Question 22

What is the cause of isolated RV failure?

Answer 22

Chronic lung disease

Question 23

What is a symptom of congestive heart failure?

Answer 23

Accumulation of fluid in interstitial of pulmonary and peripheral tissues

Question 24

What is the effect of IV furosemide?

Answer 24

Immediate venodilatory effect, can clear fluid from lungs

Question 25

What are 4 effects of beta blockers?

Answer 25

Reduce heart rate
Reduce blood pressure
Reduce mobilization of glycogen
Negate unwanted effects of catecholamines

Question 26

What is the role of ACE inhibitor?

Answer 26

Inhibit renin-angiotensin-aldosterone system, reduce water retention, vasoconstriction and sympathetic activity

Question 27

What is the effect of aldosterone receptor antagonists / spironolactone?

Answer 27

When aldosterone concentration doesn’t respond to ACE-inhibitors, aldosterone still can interact but spironolactone prevents it from interacting w receptors

Question 28

What are 4 tests to investigate heart failure?

Answer 28

ECG
CXR
Bloods
Echo

Question 29

What are the 3 blood tests to do when investigating heart failure?

Answer 29

NTpro-BNP
FBC
U&Es