3- heart failure

Question 1

what is heart failure?

Answer 1

state in which heart unable to pump blood (efficiently) at a rate commensurate with the requirements of the tissues or can do so only at high pressure
(the heart may lose its ability to pump with enough force or fill with enough blood, or both)

Question 2

what is aetiology (causes) of heart failure?

Answer 2

• coronary heart disease (people have MI and damaged heart doesn’t recover properly)
• hypertension
• dilated cardiomyopathy (can’t find a cause - some of them might have family history (hereditary) or drugs & alcohol)
• valve disease
• tachycardic arrhythmias (40-50% of HF is HEFpEF)

Question 3

what are classic symptoms of heart failure?

Answer 3

• Shortness of breath
• Difficulty breathing at night when recumbent
• Orthopnoea (shortness of breath lying down)
• Paroxysmal nocturnal dyspnoea
• Reduced exercise tolerance
• Fatigue
• Tiredness
• Ankle swelling

Question 4

what is NYHA classification system?

Answer 4

1. no limitations of physical activity - ordinary physical activity doesn’t cause HF symptoms
2. slight limitations of physical activity, comfy at rest but symptoms with activity
3. marked limitation of physical activity - comfy at rest but less than ordinary activity has symptoms
4. unable to carry on physical activity without symptoms

Question 5

what physical examinations should be done for heart failure?

Answer 5

Neck exam =Elevated jugular venous pressure

Auscultation of the lungs =Rales or crackles

Auscultation of the heart =Third or fourth heart sound (S3 or S4) sometimes called a gallop rhythm or Murmur

Oedema in dependent areas = Sacrum or Feet/ankles/lower legs

Question 6

what can ECG identify?

Answer 6

potential causes of heart failure:
- arrhythmias
- past MI
- left ventricular hypertrophy

Question 7

what can chest x-ray identify?

Answer 7

• Size and shape of the cardiac silhouette
• Evidence of fluid accumulation in the lungs

Question 8

what is transthoracic echocardiography?

Answer 8

the preferred method for documentation of cardiac dysfunction at rest (shows what’s pumping & relaxing)

Question 9

what is shown on echocardiogram?

Answer 9

• Chamber size
• Right and left ventricular function
• Regional wall motion abnormalities (evidence of MI)
• Evidence of impaired LV filling (i.e., stiffness of the walls), a feature of diastolic dysfunction
• Valvular heart disease
• Diseases of the pericardium
• Ejection fraction

Question 10

what is ejection fracture (EF)?

Answer 10

it’s a key criteria for heart failure management = it’s the % of blood pumped out heart during each beat

normal EF = > (or equal to) 50%
heart failure = > (or equal to) 40%

Question 11

what is HFrEF?

Answer 11

heart failure with reduced ejection fraction = EF >40%

• this is because LV is unable to eject adequate amount of blood in systole

Question 12

what is HFpEF?

Answer 12

heart failure with preserved ejection fraction (has normal EF)

• because less blood is able to fill the LV in diastole due to myocardial stiffness therefore LV has less blood to eject in systole

Question 13

what is the heart muscle like in HFrEF and HFpEF?

Answer 13

HFrEF = thin, weak heart muscle
HFpEF = thick, stiff heart muscle

Question 14

what is BNP and what does it indicate?

Answer 14

BNP = ventricular hormone
- tests are very sensitive so if normal then unlikely to have heart failure (good for ruling out)

Question 15

what is sensitivity?

Answer 15

a measure of how good a test or procedure is at identifying subjects with a certain condition.

Sensitivity is the proportion of subjects with the condition that are test positive.

Thus a high sensitivity is necessary to rule out the presence of disease

Question 16

what is specificity?

Answer 16

a measure of how good a test is at finding subjects without a certain condition.

Specificity is the proportion of subjects without the condition that are test negative.

Thus a high specificity is necessary to establish the presence of disease with confidence

Question 17

what is predictive value for a positive test?

Answer 17

denotes the probability that a test-positive subject has the condition he is tested for.

A high predictive value of a positive test allows the clinician to establish the presence of the condition with confidence

Question 18

what is a predictive value of a negative test?

Answer 18

denotes the probability that a test-negative subject is also without the condition he is tested for.

A high predictive value of a negative test allows the clinician to exclude the presence of the condition

Question 19

is chest x-ray sensitive & specific?

Answer 19

it is insensitive but fairly specific

Question 20

what do different levels of pro-BNP indicate?

Answer 20

if above 2000 ng/l = refer urgently for specialist assessment & echocardiography
if between 400-2000 ng/l = refer for specialist & echocardiography within 6 weeks
if less than 400 then heart failure is unlikely

Question 21

what can be done to assess if scar tissue from previous MI is causing heart failure?

Answer 21

cardiac MRI = assesses heart function and identifying whether the scar from previous MI is causing poor heart function

Size of LGE (late gadolinium enhancement) %
= LGE is contrast agent used in MRI to highlight scar tissue

assesses:
- Wall thickness: assess viable rim thickness or total wall thickness
- Infarct transmural extent by assessing myocardial cell wall integrity

Question 22

what is rehabilitation for heart failure?

Answer 22

• encourage exercise
• reduce salt intake
• 1.5 - 2L fluid intake
• treat mental health

Question 23

what are heart failure drugs that prolong survival?

Answer 23

• RAAS inhibition (ACEi & ARII antagonists) - push to max dose
• beta blockers (start low & titrate up)
• aldosterone antagonists (spironolactone & epleronone)
• vasodilators (hydralazine & nitrates combined)
• sinus node blocker
  SGLT2 inhibitors
• ivabradine

Question 24

what are drugs that improve heart failure symptoms?

Answer 24

• digoxin
• frusemide

Question 25

what is cardiac resynchronisation therapy?

Answer 25

pacemaker = 1 lead in RV and then through coronary sinus and another guide wire through coronary sinus to back of heart on left side

Question 26

what is left bundle branch block in heart failure?

Answer 26

= condition where there’s a delay or blockage in electrical signals along left bundle branch

• can lead to abnormal contractile wave-front across the LV
• causing dyssynchronous contraction (LV not contracting properly)
• results in worsening LV systolic function

*it can be fixed by pacemaker

Question 27

how does pacemaker help heart?

Answer 27

placement of lead in LV on left lateral wall aims to:
- Increases synchronous contraction
- Improves LV haemodynamics (blood flow)

Question 28

what is an example of ARNI drug?

Answer 28

entresto (gold standard)
= angiotensin receptor neprilysin inhibitor

Question 29

what therapy can help HfpEF patients?

Answer 29

exercise therapy = can improve quality of life

Question 30

what can be targeted as treatment for HFpEF?

Answer 30

obesity (can use obesity drugs) as obesity impacts natriuretic peptides, oxidative stress, RAAS & haemodynamic changes which all lead to HFpEF