Heart Failure

Question 1

What is heart failure?

Answer 1

it is a condition in which the heart is unable to generate a cardiac output sufficient to meet the demands of the body without increasing diastolic pressure (relaxation pressure; where the chambers are filling with blood)

Question 2

Heart failure can result from…

Answer 2

any cardiac disease that compromise ventricular systolic of diastolic function or both

e.g. jugular vein distension, rhythm problem, valve problem

Question 3

What are the wide range of clinical scenarios for heart failure?

Answer 3

breathlessness
oedema
tachycardia

Question 4

How is heart failure classified?

Answer 4

classified by left ventricular ejection fraction

the amount of blood the left ventricle pumps out of the body with each heart beat

Question 5

How much of the blood does the left ventricle empty itself of upon contraction?

Answer 5

the left ventricle empties itself of 50-60% of the blood it contains

Question 6

Define the left ventricular ejection fraction

Answer 6

this is the percentage of the blood within the ventricle pumped out to the systemic circulation per heartbeat

Question 7

What does the left ventricular ejection fraction measure?

Answer 7

it measures the pumping efficiency of the heart

Question 8

How is the left ventricular ejection fraction percentage calculated?

Answer 8

Stroke volume (L)/end diastolic volume (L) x 100

end diastolic volume- volume in the chambers of the heart after diastole (relaxation)

Question 9

What is the normal LVEF%?

Answer 9

50-65%

Question 10

What is the LVEF% for heart failure with reduced ejection fraction?

Answer 10

<40%
here the heart is not ejecting much of the blood contained in the left ventricle

Question 11

What is the LVEF% for heart failure with mildly reduced ejection fraction?

Answer 11

40-49%

Question 12

What is the LVEF% for heart failure with preserved ejection fraction?

Answer 12

> 50%

Question 13

What are the other methods of classifying heart failure?

Answer 13

side of heart (affected)
functional
symptoms
stage

Question 14

What are the consequences of right hand side heart failure?

Answer 14

fluid collection
often leads to swollen ankles and lungs

Question 15

Right side heart failure compromises ___________ whilst left side heart failure compromises ______________.

Answer 15

pulmonary flow
systemic flow

Question 16

The New York Heart Association classes heart failure from I-IV. What does class I heart failure indicate?

Answer 16

indication of no limitation to any activity

Question 17

The New York Heart Association classes heart failure from I-IV. What does class II heart failure indicate?

Answer 17

indication of a mild limitation, comfortable at rest

Question 18

The New York Heart Association classes heart failure from I-IV. What does class III heart failure indicate?

Answer 18

marked limitation, only comfortable at rest

Question 19

The New York Heart Association classes heart failure from I-IV. What does class IV heart failure indicate?

Answer 19

symptoms occur at rest

Question 20

Heart failure can be classified by symptoms. The Framingham criteria attempts to this. Briefly explain the idea behind the framingham criteria

Answer 20

attempts to diagnose heart failure based on major and minor criteria
Major criteria include: cardiomegaly, hepatojugular reflux, acute pulmonary oedema, neck vein distension

Minor criteria include: ankle oedema, hepatomegaly, tachycardia, nocturnal cough, dyspnoea

Question 21

What is required for a definitive diagnosis of heart failure with the framingham criteria?

Answer 21

2 major criteria OR
1 major and 2 minor criteria

Question 22

Heart failure can be classified in stages. The American college of cardiology classes HF from stage A-D. What is stage A heart failure?

Answer 22

high risk but no functional/structural/symptoms

Question 23

Heart failure can be classified in stages. The American college of cardiology classes HF from stage A-D. What is stage B heart failure?

Answer 23

structural disease, no symptoms

Question 24

Heart failure can be classified in stages. The American college of cardiology classes HF from stage A-D. What is stage C heart failure?

Answer 24

structural disease with symptoms

Question 25

Heart failure can be classified in stages. The American college of cardiology classes HF from stage A-D. What is stage D heart failure?

Answer 25

advanced structural disease with symptoms

Question 26

What are common cause of of chronic heart failure?

Answer 26

coronary artery disease (e.g. angina) hypertension valvular disease myocarditis (inflammation of the cardiac myocytes)- viral infection of muscle, can stop heart muscles from working

Question 27

What is the Frank- Starling Law?

Answer 27

this law states that the stroke volume increases in response to the end diastolic volume when all other factors remain constant so stroke volume increases if the volume of the blood in the ventricles before contraction increases If more blood is available in the ventricles, more blood will be pumped out of the ventricles

Question 28

What occurs in response to larger volumes of blood entering the ventricles?

Answer 28

the cardiac muscle stretches this will as such lead to an increased force of contraction sacromeres (unit of heart muscle contraction) may over stretched and become damages

Question 29

Briefly state the pathophysiology of heart failure

Answer 29

Myocardial insult ------> Myocardial remodelling-----> failure of frank-starling law -----> reduced cardiac output -----> fluid retention and increased peripheral vascular resistance failure of frank-starling law (stroke volume no longer increases with an increase in end diastolic volume)

Question 30

What occurs in systolic dysfunction ?

Answer 30

enlarged ventricles are filled with blood however the ventricles pump out <40-50% of the blood

Question 31

What occurs in diastolic dysfunction?

Answer 31

the stiff ventricles are filled with less blood than normal the ventricles will pump out 60% of this (reduced) blood

Question 32

What does initial myocardial insult lead to?

Answer 32

over-expression of multiple peptides and neurohormonal activation left ventricular remodelling

Question 33

What are the markers of left ventricular hypertrophy ? What does this lead to?

Answer 33

loss of myocytes interstitial fibrosis this leads to stretched and stiff myocardium Sacromeres are over-stretched (leads to stiffness of the myocardium)

Question 34

Cardiac remodelling eventually leads to the failure of __________.

Answer 34

frank-starling curve - essentially LV is unable to pump as much blood as required out [stroke volume increases with increased end diastolic volume if all other factors remain the same]

Question 35

Reduced stroke volume is a result of the failure of ...?

Answer 35

diastole, systole or both

Question 36

Further strain of remodelled cardiac muscle leads to ...

Answer 36

increased ischaemia (loss of oxygen)

Question 37

What are the consequences of reduced cardiac output?

Answer 37

Fall in mean arterial pressure (diastole+systole) leads to sympathetic activity causing systemic vasoconstriction and increased peripheral vascular resistance ADH released (reduced cardiac output would initially cause hypovolaemia which causes compensatory ADH mechanism?) due to sympathetic activity, leads to water retention at collecting ducts increasing blood volume RAAS activated leading to periphera vasoconstriction (angiotensin II) and Na+/H2O retention (aldosterone) Skeletal muscle atrophy

Question 38

What is the presentation of heart failure?

Answer 38

dyspnoea neck vein distention S3 gallop ? cardiomegaly hepatojugular reflex basal crackles orthpnoea PND (paroxymal nocturnal dyspnoea) - sudden shortness of breath that comes shortly after falling asleep Tachycardia chest pain ankle oedema night cough fatigue/muscle weakness palpitations syncope confusion (minor criteria)

Question 39

What are the strong risk factors for heart failure?

Answer 39

diabetes myocardial infarction dyslipidaemia age male hypertension cocaine abuse

Question 40

What are the weak risk factors for heart failure ?

Answer 40

low socio economic status smoking alcohol obesity coffee

Question 41

What investigations are carried out to diagnose heart failure?

Answer 41

Echocardiogram** Electrocardiogram chest xray B-type natriuretic peptide Serum: FBC, U&Es (urea and electrolytes), glucose, lipids, TFTs(thyroid functional test), LFTs (liver functional tests) exercise test cardiac MRI

Question 42

What is the medication often prescribed for heart failure?

Answer 42

ACEi beta- blockers diuretics (combat fluid build up) digoxin ivabradine aldosterone antagonist (RAAS)

Question 43

What is the management of heart failure?

Answer 43

medication lifestyle changes implantable caridac defibrillator heart transplant pacemaker

Question 44

What are the dental considerations of patients with heart failure?

Answer 44

polypharmacy dry mouth (diuretics) anticoagulants - increased bleeding risk poor healing increased risk of infections oxygen requirement reduced exercise tolerance- carefully plan procedures in combination with cardiology team including heart failure nurses DO NOT LIE PATIENT FLAT