Chronic Heart Failure:epidemiology, investigation and diagnosis

Question 1

What is the definition of heart failure?

Answer 1

A clinical syndrome comprising of dyspnoea, fatigue or fluid retention due to cardiac dysfunction, either at rest or on exertion, with accompanying neurohormonal activation

Question 2

What is the prevalence of heart failure and of asymptomatic LVSD?

Answer 2

Heart failure: 0.4 - 2%

Asymptomatic LVSD: 0.4 - 2%

Prevalence and incidence increase with age (mean age 74years)

Estimated 40-60 000 patients with HF/LVSD(left ventricular systolic dysfunction) in Scotland

Question 3

What is the largest cost attached to heart failure

Answer 3

Hospital inpatient care

Question 4

What can be said about re-admission rates for HF?

Answer 4

High! and readmission is most likely to happen early.

Length of hospital admission is longer than any other condition.

Question 5

What are the signs of heart failure?

Answer 5

Breathlessness

Fatigue

Oedema

Reduced exercise capacity

Question 6

What are the signs of heart failure?

Answer 6

Oedema

Tachycardia

Raised JVP

Chest crepitations or effusions

3rd Heart sound

Displaced or abnormal apex beat

Question 7

Is heart failure easy to diagnose based on clinical signs alone?

Answer 7

Yes very difficult - diagnosis incorrect in approximately 40-50% of cases

Question 8

What are the 3 key features that indicate heart failure?

Answer 8

Symptoms and signs of HF (rest or at exercise)

Objective evidence of cardiac dysfunction and in (doubtful cases)

Resonse to therapy

(They look like they have it, tests think they have it, and they respond to treatment)

Question 9

What is objective evidence of cardiac dysfunction?

Answer 9

•Echocardiography, Radionuclide ventriculography (RNVG/MUGA), MRI, left ventriculography

Question 10

What are the screening tests available?

Answer 10

12 lead ECG - left ventricular systolic dysfunction is very unlikely if there is a normal ECG but it is still possible (90-95% sensitive)

(Problems with confidence of interpretation in primary care, must be entirely normal or else loses reliability)

BNP (brain (B-type) natriuretic peptide)

Amino acid peptide can be measured easily in bood

–Elevated in heart failure, therefore low BNP effectively excludes heart failure

Potential as diagnostic/ screening test for long time

Question 11

What does a high / low BNP indicate?

Answer 11

•Low BNP effectively rules out heart failure or LVSD, elevated BNP indicates need for an echo/cardiac assessment

Question 12

What is the common rule as to what will cause heart failure?

Answer 12

If sufficiently severe almost any structural cardiac abnormality will cause heart failure

e.g

• LV systolic dysfunction – many causes
• Valvular heart disease
• Pericardial constriction or effusion
• LV diastolic dysfunction/heart failure with preserved systolic function/heart failure with normal ejection fraction
• Cardiac arrhythmias: tachy or brady
• Myocardial ischaemia/infarction (usually via LVSD)
• Restrictive cardiomyopathy eg amyloid, HCM
• Right ventricular failure: primary or secondary to pul hypertension

Question 13

What are common causes of LV systolic dysfunction?

Answer 13

Ischaemic heart disease (usually MI)

•Dilated cardiomyopathy(DCM): Means LVSD not due to IHD or secondary to other lesion ie valves/VSD

e.g

–Inherited

–Toxins: eg alcohol, catecholamines (phaeochromocytoma or stress cardiomyopathy (takosubo’s cardiomyopathy)

–Viral: acute myocarditis or chronic DCM

–Other infective: HIV, chaga’s disease, Lyme’s disease…….

–Systemic disease: sarcoidosis, haemachromatosis, SLE, mitochondrial dis.

–Muscular dystrophies

–Peri-partum cardiomyopathy (post pregnancy)

–Hypertension

–Isolated non compaction

–Tachycardia related cardiomyopathy

–RV pacing induced cardiomyopathy

–End stage hypertrophic cardiomyopathy

–End stage arrhythmogenic RV cardiomyopathy

Severe aortic valve disease or mitral regurgitation

Question 14

How do you figure out which type of heart failure is present? IHD, valvular disease or dilated cardiomyopathy

Answer 14

Take a detailed history - may provide answer

Esculde renal failure, anaemia, thyroid function tests

Serology to check for viruses and autoantibodies

Consider to exclude phaechromocytoma (cancer in the adrenal gland)

Consider other causes such as thyroid, muscular dystrophy

ECG, ECHO and sometimes a CXR

Consider coronary angiography in patients with chest pain who are over 70.

Cardiac MRI looking for infarction, inflammation and fibrosis

Question 15

Why is echocardiography always an essential investigation?

Answer 15

Assesses:

–LV systolic dysfunction

–Valvular dysfunction

–Pericardial effusion / tamponade

–Diastolic dysfunction

–LVH

–Atrial/ventricular shunts / complex congenital heart defects (ventral septal defects)

–Pulmonary hypertension / Right heart dysfunction

•May not identify constriction / may miss shunts (but you will see atrial dilatation)

Question 16

What changes LVEF?

Answer 16

•Disease / physiological changes can both decrease and increase the LVEF - it is however a continuous biological variable like haemoglobin / anaemia

Question 17

Can LV ejection fraction be calculated by echo?

Answer 17

Yes but it is difficult to quantify accurately and reproducably

Depends on:

–Quality of images

–Experience of operator

–Calculation method –

• M-mode
• Simpson’s biplane

–Use of contrast agents

–Time-consuming to perform accurately

–Normal range is centre specific, but LVEF not routinely measured and NR not routinely established

Question 18

What are the normal, mild, moderate and severe LVEF?

Answer 18

• normal (50-80%)
• mild (40-50%)
• moderate (30-40%)
• severe (<30%)

Question 19

What is LVEF MUGA?

Answer 19

• Much easier to obtain an accurate figure for the LVEF
• Greater reproducibility
• Ionising radiation
• No additional structural information
• centre specific normal range

Question 20

What is a potent predictor of death in hospitalized heart failure patients?

Answer 20

Left ventricular systolic function

Question 21

Not really in learning outcomes

Answer 21

Question 22

Does heart failure always reduce cardiac output?

Answer 22

NO - very complex problem

Question 23

Why is HF considered a systemic disorder?

Answer 23

Because it involves cardiac dysfunction, renal dysfunction, skeletal muscle dysfunction, systemic inflammation and neurohormonal activation

Question 24

How is the renin - angiotensin - aldosterone system affected by systemic HF?

Answer 24

Causes salt and water retention (by reduced blood flow to the kidneys)

Adverse haemodynamics

Causes an increase in blood volume - causes LY hypertrophy / remodelling and fibrosis (of LV)

Hypokalaemia and hypomagnesaemia

Question 25

How does neurohormonal activation affect the sympathetic nervous system?

Answer 25

It is arrythmogenic, adverse haemodynamics, increase in renin etc

Question 26

What is Left ventricular injury a result of?

Answer 26

Coronary artery disease

Hypertension

Cardiomyopathy

Valvular heart disease

Neurohormonal activation - for example renin-angiotensin-aldosterone system)

Question 27

What is the result of left ventricular injury?

Answer 27

Left ventricular dysfunction - leading to pump failure, arrythmia, heart failure and even death

Question 28

What are the outcomes of neurohormonal activation?

Answer 28

Vasoconstriction

Endothelial dysfunction

Renal sodium retention

Question 29

What are the resultant symptoms of neurohormonal ativation?

Answer 29

Dyspnoea

Fatigue

Oedema

HEART FAILURE

Question 30

What is modern pharmacological treatment of heart failure?

Answer 30

–Diuretics

–ACE inhibitors

–Betablockers

–Aldosterone receptor blockers

–ARBs

In some patients, ACEI or ARB are now replaced by

ARNI’s: angiotensin receptor neprilysin inhibitor – makes use of beneficial neurohormonal systems (BNP?)