Lecture 12: Chronic heart failure

Question 1

What is the definition of heart failure?

Answer 1

A state that develops when the heart fails to maintain an adequate cardiac output to meet the demands of the body

Question 2

What is systolic HF?

Answer 2

Structural or functional abnormality that impairs the ability of the ventricle to eject blood

Question 3

What is diastolic HF?

Answer 3

Structural or functional abnormality that impairs the ability of the ventricle to fill with blood

Question 4

What is the equation for CO?

Answer 4

CO = HR x SV

Question 5

What is preload?

Answer 5

Volume of blood or stretching of cardiomyocytes at the end of diastole prior to the next contraction

Question 6

What is after load?

Answer 6

Resistance/end load against which the ventricle contracts to eject blood

Question 7

What happens to CO as after load increases?

Answer 7

Decreases

Question 8

What is high output HF?

Answer 8

Occurs in the context of other medical conditions which increase demands on cardiac output, causing a clinical picture of HF

Question 9

What may cause high output HF?

Answer 9

Thyrotoxicosis, profound anaemia, pregnancy, pagets disease, acromegaly, sepsis

Question 10

What may cause systolic HF?

Answer 10

Ischaemic injury
Volume overload
Pressure overload

Question 11

What may cause diastolic HF?

Answer 11

Significant left ventricular hypertrophy (LVH) e.g HCM

Infiltrative disorders

Constrictive pericarditis

Restrictive cardiomyopathy

Question 12

What is the definition of cardiomyopathy?

Answer 12

Diffuse disease of the heart muscle leading to functional impairment

Question 13

What are the three types of cardiomyopathy?

Answer 13

Dilated (various causes)

Hypertrophic (hereditary)

Restrictive (amyloid - rare)

Question 14

What are the effects of active BNP?

Answer 14

Diuresis
RAAS inhibition
SNS inhibition
Vasodilation

(half life 20 minutes)

Question 15

What is the inactive form of BNP?

Answer 15

NT-proBNP

half life 2 hours

Question 16

What are the HF compensatory mechanisms?

Answer 16

Vasoconstriction
Na and water retention
Tachycardia

Question 17

What is left sided HF?

Answer 17

Blood backs up progressively from the left atrium to the pulmonary circulation

Question 18

What may causes left sided HF?

Answer 18

Ischaemic heart disease
Hypertension
Valvular heart disease
Myocardial disease

Question 19

What are the symptoms of left sided HF?

Answer 19

Pulmonary congestion and oedema (breathlessness, orthopnoea, paroxysmal nocturnal dyspnoea)

Reduced renal perfusion (retention of salt and water - increased blood volume)

Hypoxic encephalopathy (irritability, loss of attention, restlessness, stupor and coma)

Question 20

What is congestive HF?

Answer 20

Right sided HF as a result of left sided HF

Question 21

What is cor-pulmonale?

Answer 21

Right sided HF due to significant pulmonary hypertension due to increased resistance within the pulmonary circulation - usually as a result of respiratory disease e.g. COPD or pulmonary emboli

Question 22

What are the systemic effects of right heart failure?

Answer 22

Congestive hepatomegaly

Centrilobular necrosis

Cardiac cirrhosis

Congestive splenomegaly

Ascites

Peripheral or sacral oedema

Effusions

Question 23

What are the classes of HF?

Answer 23

Class I: No limitation of physical activity

Class II: Slight limitation of ordinary activity

Class III: Marked limitation, even during less-than-ordinary activity

Class IV: Severe limitation with symptoms at rest

Question 24

What are the clinical signs of cardiac failure?

Answer 24

Cool, pale, cyanotic extremities

Tachycardia

Elevated JVP

Third heart sound (S3) – gallop rhythm

Displaced apex (LV enlargement)

Crackles or decreased breath sounds at bases on chest auscultation

Peripheral oedema

Ascites

Hepatomegaly

Question 25

What are the clinical test in HF?

Answer 25

CXR ECG Blood investigations Echocardiogram / Cardiac MRI or CT / CT-PET CTCA / Coronary angiography

Question 26

What values of NT-proBNP are used?

Answer 26

>2000ng/L - refer urgently within 2 weeks 400-2000 - refer urgently within 6 weeks <400 - HF not confirmed

Question 27

What would you prescribe for HF with reduced ejection fraction?

Answer 27

ACE inhibitor and beta blocker | consider ARB if intolerant of ACEI

Question 28

What would you prescribe for HF with preserved ejection fraction?

Answer 28

Manage comorbidities e.g. hypertension, AF, IHD

Question 29

Name a loop diuretic.

Answer 29

Frusemide or bumetanide Inhibit Na+ re-absorption from the proximal tubule and K+ loss from distal tubule (can be given iv or orally)

Question 30

Name a mineralocorticoid antagonist.

Answer 30

Eplerenone or spironolactone Acts on distal tubule, promotes Na+ excretion and K+ re-absorption Reduces hypertrophy and fibrosis

Question 31

Name an ACE inhibitor.

Answer 31

Ramipril

Question 32

What kind of drug is bisprolol?

Answer 32

Beta blocker

Question 33

What kind of drug is ivabradine?

Answer 33

Blocks the If channel in the SA node Slows HR, no effect on BP Given orally with dose titration (SE: visual aura, bradycardia)

Question 34

How does digoxin work?

Answer 34

Increases myocardial contractility Slows conduction at the AV node (use in AF) (Excreted by kidney - toxicity important)

Question 35

How do ARNIs work?

Answer 35

Blocks breakdown of ANP/BNP Blocks RAAS Promotes naturesis (SE: hypotension, renal impairment)

Question 36

Name an ARNI.

Answer 36

Sacubitril or valsartan