Chronic Heart Failure - 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

Describe the prevalence and incidence of heart failure?

Answer 2

Increases with age - mean age of 74 years
Around 60,000 patients with HF/LVSD in Scotland

Question 3

Why is there is an increasing risk of CHF?

Answer 3

Treatment of AMI, aging population, increase prevalence and incidence of hypertension, CHD, Obesity, Diabetes and HLP

Question 4

What can contribute to a decreasing risk of CHF for the population?

Answer 4

Treatment and diagnosis of HLP, Hypertension, CHD, Diabetes and obesity

Question 5

Describe the prognosis of Heart failure

Answer 5

One-year survival rate for heart failure is worse than for cancer of breast, uterus, prostate and bladder
Also expensive for NHS

Question 6

Describe hospital re-admissions for people with heart failure

Answer 6

High death rate on initial admission
Re-admissions often happen in first week and are high
Happen usually early

Question 7

Describe HF in terms of mortality and morbidity

Answer 7

High morbidity and mortality

Question 8

What are the symptoms of heart failure?

Answer 8

Breathlessness, fatigue, oedema and reduced exercise capacity

Question 9

What are the clinical signs of heart failure?

Answer 9

Oedema, tachycardia, raised JVP, chest creps or effusions, 3rd heart sound and displaced or abnormal apex beat

Question 10

What can be seen on an X-ray if patient has HF?

Answer 10

Gross cardiomegaly, pleural effusions and oedema

Question 11

Can you diagnose HF on clinical grounds alone?

Answer 11

No as difficult cause symptoms and signs are non-specific
Objective evidence for cardiac dysfunction if mandatory

Question 12

What is needed for diagnosis of Heart failure?

Answer 12

Symptoms or signs of HF (rest or exercise)
Objective evidence of cardiac dysfunction
Response to therapy (diuretics) in doubtful cases

Question 13

How do you obtain objective evidence of cardiac dysfunction?

Answer 13

Echocardiography, Radionuclide ventriculography (RNVG?MUGA), MRI, left ventriculography

Question 14

What are potential screening tests for HF?

Answer 14

12 lead ECG - LVSD is unlikely if ECG is normal
BNP (brain natriuretic peptide) - measured easily in blood and is elevated in heart failure
Low BNP can exclude HF
Recommended BNP first line in suspected HF

Question 15

Describe BNP as a screening test for heart failure

Answer 15

Highly sensitive test for HF and is stable for 72hrs so suitable for community testing
Low BNP rules out HF or LVSD
Elevated BNP indicates need for Echo/ cardiac assessment

Question 16

Can BNP predict mortality and morbidity?

Answer 16

Yes, Higher BNP then higher risk

Question 17

What condition if severe enough will cause heart failure?

Answer 17

Any structural cardiac abnormality

Question 18

Name some structural cardiac abnormalities that could lead to HF if sufficiently severe

Answer 18

LVSD, Valvular heart disease, pericardial constriction or effusion, LV diastolic dysfunction (Heart failure with normal ejection fraction), cardiac arrhythmias, MI, Restrictive cardiomyopathy, and Right ventricular failure

Question 19

What can causes LV systolic dysfunction?

Answer 19

Ischaemic heart disease
(usually MI)
Dilated cardiomyopathy - LSVD not due to IHD or secondary to other lesion (valves/VSD)
Severe aortic valve disease or mitral regurgitation

Question 20

What are some causes of dilated cardiomyopathy (DCM)?

Answer 20

Inherited is most common, toxins, viral and other infectives, systemic disease and hypertension…

Question 21

What can be included in a patients history of LVSD?

Answer 21

MI, DM, HBP, post partum and alcohol.
Lyme disease, IDVA, HIV
Consider familial
Sarcoid, muscular dystrophy

Question 22

What is good to exclude in a patient when diagnosing LVSD?

Answer 22

Renal failure, anaemia, TFTs (thyroid), pheochromocytoma

Question 23

What investigations can be used in diagnosis of LVSD?

Answer 23

ECG and sometimes CXR
Always do an Echo
Consider coronary angiography - essential if chest pain and patients over 70
CT coronary angiogram
Cardiac MRI can look for infarction, inflammation and fibrosis

Question 24

What can an Echo identify and quantify?

Answer 24

LVSD, valvular dysfunction, pericardial effusion/ tamponade, diastolic dysfunction, LVH, Atrial/ ventricular shunts and pulmonary hypertension

Question 25

What are some benefits and negatives of an echo?

Answer 25

Simple and non-invasive. No ionising radiation May not identify constriction or may miss shunts but you will see AF or if the heart is under strain

Question 26

Explain 2D views of an echo?

Answer 26

Parasternal long axis Parasternal short axis - papillary muscle level Parasternal short axis - base

Question 27

What will severe LV systolic dysfunction look like on an echo?

Answer 27

LV more globular shape - dilated Systolic motion is also impaired

Question 28

Describe LV ejection fraction

Answer 28

Assesses how impaired LV is LV ejection fraction is a continuous biological variable Disease/ physiological changes can both decrease and increase the LVEF Chemo can lower LVEF

Question 29

What makes LV ejection fraction difficult to quantify by echo?

Answer 29

Quality of images Experience of operator Calculation methods very - M-mode and Simpsons biplane (gold standard) Use of contrast agents Time consuming

Question 30

Describe LV function assessment and LVEF percentage?

Answer 30

Normal - 55-70% Mild - 40-55% Moderate - 30-40% Severe - <30%

Question 31

Describe Biplane modified Simpsons Rule

Answer 31

Way of calculating the LVEF Divides LV cavity into multiple slices of known thickness and diameter - is 2D visualising 3D Volume of each slice - area x thickness - thinner slices are more accurate Endocardial border traced accurately

Question 32

Describe an echo constrast

Answer 32

Used to improve endocardial border detection Lights up the LV cavity and can easily see the border

Question 33

Describe a MUGA scan

Answer 33

Nucleotide technique - ionising radiation Greater reproducibility No additional structural info. Centre specific normal range Easier to obtain an accurate figure for the LVEF if heart rhythm is irregular

Question 34

Describe a cardiac MRI benefits and negatives

Answer 34

More accurate then echo as can get additional info. of tissue characteristics Is expensive, slow, requires breath-holding and can be claustrophobic Good for looking at LV hypertrophy

Question 35

Describe the grading classification of heart failure

Answer 35

NYHA classification 1 - no symptoms 2 - comfortable with rest or mild exercise 3 - comfortable only at rest 4 - any physical activity brings discomfort and symptoms at rest

Question 36

How do you grade the severity of HF?

Answer 36

Degree of LV impairment (or valvular dysfunction) NYHA class - severity of symptoms Degree of elevation of BNP - not used as much

Question 37

Why does structural abnormalities in the heart cause the syndrome of HF?

Answer 37

HF is not a simple mechanical problem HF is a systemic disorder - cardiac dysfunction, renal, skeletal, systemic inflammation and neurohormonal activation

Question 38

How does RAAS contribute to HF?

Answer 38

Salt and water retention Adverse haemodynamics LV hypertrophy/ remodelling or fibrosis Electrolyte disturbances - low K and Magnesium

Question 39

How does SNS contribute to HF?

Answer 39

Arrhythmogenic Adverse haemodynamics and increases renin so vicious cycle Also vasoconstricts

Question 40

What can left ventricular dysfunction cause?

Answer 40

Arrhythmia, pump failure, neurohormonal activation and HF