Heart failure Flashcards
What is the definition of heart failure?
A state that develops when the heart fails to maintain an adequate cardiac output to meet the demands of the body
What does heart failure result from?
Results from any structural or functional abnormality that impairs the ability of the ventricle to eject blood (systolic HF) or fill with blood (diastolic HF)
What is the equation for cardiac output?
What is the normal value for cardiac output?
At rest, cardiac output is typically 70mls/kg/min
How does an increased heart rate increase cardiac output?
Heart contracts in systole and relaxes in diastole. Ventricular filling occurs in diastole
Excessively high HR results in a decrease in the amount of time allowed for the ventricles to fill in diastole which causes SV and, thus CO to fall
What 3 things make up stroke volume?
Contractility: the intrinsic ability of the myocardium to contract
Preload: the volume of blood or stretching of cardiomyocytes at the end of diastole prior to the next contraction
Afterload: the resistance/end load against which the ventricle contracts to eject blood
What is preload?
The volume of blood or stretching of cardiomyocytes at the end of diastole prior to the next contraction
What is preload affected by?
Is affected by venous blood pressure and the rate of venous return to the heart
This, in turn, is affected by venous tone and volume of circulating blood
What increases and decreases preload?
Preload increases with increasing blood volume and vasoconstriction
Preload decreases with blood volume loss and vasodilatation
What is Frank-Starling Law?
Describes the relationship between Preload and Cardiac Output
States that….
- An increase in volume of blood filling the heart stretches the heart muscle fibres causing greater contractile forces which, in turn, increases the stroke volume
- Is true only up to a certain point… at some stage the fibres become over-stretched and the force of contraction is reduced
According to Frank-Starlings Law, what will happen if there is a increased preload?
What is afterload?
The resistance/end load against which the ventricle contracts to eject blood
It is the pressure in the aorta/pulmonary artery that the left/right ventricular muscle must overcome to eject blood
Does preload or afterload increase when the pressure increases in the pulmonary artery/aorta?
Afterload
What increases and decreases afterload?
Afterload increase with hypertension and vasoconstriction
Afterload decreases with vasodilatation
What happens to cardiac output when afterload increases?
As the afterload increases, cardiac output decreases
What is low output heart failure?
Systolic heart failure
Diastolic heart failure
What is high output heart failure?
Occurs in the context of other medical conditions which increase demands on cardiac output, causing a clinical picture of heart failure
The heart itself is functioning normally but cannot keep up with the unusually high demand for blood to one or more organs in the body
Name some causes of high output heart failure
thyrotoxicosis, profound anaemia, pregnancy, pagets disease, acromegaly, sepsis
What is systolic heart failure?
Progressive deterioration myocardial contractile function
What is diastolic heart failure?
Inability of the heart chamber to relax, expand and fill sufficiently during diastole to accommodate an adequate blood volume
What are the 3 types of systolic heart failure?
Ischaemic injury
Volume overload
Pressure overload
What are the 4 types of diastolic heart failure?
- Significant left ventricular hypertrophy (LVH) e.g HCM
- Infiltrative disorders
- Constrictive pericarditis
- Restrictive cardiomyopathy
What are the 5 causes of heart failure?
Coronary Heart Disease
Hypertensive Heart Disease
Valvular Heart Disease
Myocardial Disease/ Cardiomyopathies
Congenital Heart Disease
What is the definition of cardiomyopathies?
Diffuse disease of the heart muscle leading to functional impairment
What are the 3 types of cardiomyopathies?
Dilated Cardiomyopathy
Hypertrophic Cardiomyopathy (hereditary)
Restrictive Cardiomyopathy (rare)
What are the causes of dilated cardiomyopathy?
–ETOH, pregnancy, systemic disease (SLE), muscular dystrophies
–Drug toxicity (chemotherapy – anthracyclines, herceptin)
–Myocarditis – Aetiology includes viral (enteroviruses – coxsackie B), HIV
What is the main cause of restrictive cardiomyopathy?
Amyloid the main cause in the UK
What does pump failure lead to?
Reduced stroke volume and cardiac output
Why do compensatory mechanisms kick in at decreased SV + CO?
To maintain arterial pressure and perfusion of vital organs
What are the compensatory mechanisms in heart failure?
The Frank Starling mechanism: vasoconstriction, increased venous return to the heart, increased preload, heart muscle fibres stretch, enhanced contractility
Myocardial structural change: Augmented muscle mass (hypertrophy) with or without cardiac chamber dilatation
Activation of neurohormonal system
During compensation, what neurohormonal compounds are released?
Release of Noradrenaline – increases heart rate and myocardial contractility. Causes vasoconstriction
Release of ANP/BNP
Activation of renin-angiotensin – aldosterone system
Complete the diagram on the RENIN, ANGIOTENSION, ALDOSTERONE SYSTEM
What is the NP system?
NP - natriuetic peptide
Activated by increased ventricular wall stretch
Complete the diagram on the NP system

How does the NP system cause decreased vasodilatation?
Decreased BP
Decreased sympathetic tone
Decreased aldosterone levels
Natriuresis
Diuresis
Antifibrotic effects
Complete the diagram on activation of the sympathetic nervous system

What 3 compensatory mechanisms may succesfully restore cardiac output but worsen heart failure?
Vasoconstriction: ↑resistance against which heart has to pump (i.e.↑afterload), and may therefore ↓ CO
Na and water retention: ↑fluid volume, which ↑ preload. If too much “stretch” → ↓ contractile strength and CO
Excessive tachycardia → ↓diastolic filling time → ↓ventricular filling → ↓SV and CO
What are the 3 clinical types of heart failure?
Left sided, right sided and biventricular failure
Acute and chronic heart failure
Compensated and decompensated heart failure
What is left sided heart failure?
Blood backs up progressively from the left atrium to the pulmonary circulation
What are the causes of left sided heart failure?
Ischaemic heart disease
Hypertension
Valvular heart disease
Myocardial disease
What is the effect of left ventricular failure in the lungs?
Pressure in the pulmonary veins is transmitted retrogradely to the capillaries and arteries
This leads to pulmonary congestion and oedema
Heavy wet lungs
What is the effect of left sided ventricular failure in the kidneys?
Decreased cardiac output
Reduction in renal perfusion
Activation of renin - angiotensin – aldosterone system
Retention of salt and water with consequent expansion of interstitial fluid and blood volumes
What are the symptoms of left ventricular heart failure in the lungs?
What are the symptoms of left sided ventricular heart failure in the brain?
Hypoxic encephalopathy
Irritability
Loss of attention
Restlessness
Stupor and coma
What causes right sided heart failure?
Usually as a consequence of left sided heart failure (congestive cardiac failure (CCF))
Other causes -
- Valvular heart disease
- Congenital heart disease
What is cor-pulmonale?
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
What causes cor-pulmonale?
Usually as a result of respiratory disease e.g. COPD or pulmonary emboli
What are the effects of right sided heart failure on the liver and portal system?
Congestive hepatomegaly
Centrilobular necrosis when severe
Cardiac cirrhosis
What are the effects of right sided heart failure on the spleen?
Congestive splenomegaly
What is the effect of right sided heart failure on the abdomen?
Ascites - accumulation of transudate in peritoneal cavity
What are the effects of right sided heart failure on subcutaneous tissue?
Peripheral oedema of dependent portions of the body esp. ankle and pretibial oedema
Sacral oedema if bedridden
What is the effect of right sided heart failure on the pleural and pericardial space?
Effusions
Which parts of the body does right sided heart failure have systemic effects on?
Liver and portal system
Spleen
Abdomen
Subcutaneous tissue
Pleural and pericardial space
What is congestive heart failure?
Biventricular failure
What are the causes of congestive heart failure?
Either due to the same pathological process on each side of the heart
OR
A consequence of left heart failure leading to volume overload of the pulmonary circulation and eventually the right ventricle causing right ventricular failure
What are the symptoms of congestive heart failure which are due to excess fluid accumulation?
Dyspnoea
Orthopnoea, paroxysmal nocturnal dyspnoea
Oedema
Hepatic congestion
Ascites
What are the symptoms of congestive heart failure that are due to reduction of cardiac output?
Fatigue
Weakness
What are the 4 classes of heart failure?
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
What are the clinical signs of heart failure?
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
What clinical tests are used in heart failure?
CXR
ECG
Blood investigations
Echocardiogram / Cardiac MRI or CT / CT-PET
CTCA / Coronary angiography
Complete the diagram on the NICE guidelines for chronic heart failure treatment

Name 2 loop diuretics
FRUSEMIDE, BUMETANIDE
What is LVSD?
Left ventricular systolic dysfunction
How do loop diuretics work?
Inhibit Na+ re-absorption from the proximal tubule
K+ loss from distal tubule
How can loop diuretics be administered?
Can be given iv or orally
What dangerous side effects can loop diuretics lead to?
electrolyte abnormalities
hypovolaemia and diminished renal perfusion
How do mineralocorticoid receptor antagonists work?
Acts on distal tubule
Promotes Na+ excretion and K+ re-absorption
Reduces hypertrophy and fibrosis
Name 2 mineralocorticoid receptor antagonists
EPLERENONE, SPIRONOLACTONE
What are the possible side effects of Mineralocorticoid Receptor Antagonists?
Gynaecomastia (esp. Spironolactone)
Electrolyte (K+ high) and renal function abnormalities
Name some ACE inhibitors used in heart failure
RAMIPRIL, PERINDOPRIL, ENALAPRIL, CAPTOPRIL, LISINOPRIL
How do ACE inhibitors work?
Act on activated renin - angiotensin system
Block production of angiotensin:
- Vasodilatation
- BP lowering
- Reduce cardiac work
How are ACE inhibitors adminstered?
Given orally in small doses with slow titration
What are the side effects of ACE inhibitors?
cough, hypotension, renal impairment
Name some beta blockers used in heart failure
BISOPROLOL, CARVEDILOL, METOPROLOL
How do beta blockers work?
Block the action of adrenaline and noradrenaline on adrenergic beta receptors
Slow HR, reduce BP
(treat arrhythmias)
How are beta blockers administered?
Given orally in small doses with slow titration
What are the side effects of beta blockers?
Bronchospasm
Claudication
How does digoxin work?
Increases myocardial contractility
Slows conduction at the AV node (use in AF)
How is digoxin excreted?
Excreted by kidney - Toxicity important
What is digoxin prescribed to a patient for?
Acute HF especially in AF
Chronic HF in selected cases
Name 2 ARNIs
SACUBITRIL
VALSARTAN
What do ARNIs do?
Acts on activated renin - angiotensin system
Also blocks breakdown of ANP/BNP
Block production of angiotensin:
- Vasodilatation, BP lowering, reduce cardiac work
Promote natriuresis
- Sodium excretion, vasodilatation, reduce hypertrophy and fibrosis
What are the side effects of ARNIs?
hypotension, renal impairment
What is the mechanism of action for ARNIs?
Dual NEP and RAAS inhibition

Name an SA node blockade drug
IVABRADINE
How do SA node blockade drugs work?
Blocks the If channel within the SA node
Slow HR, no effect on BP
How are SA node blockade drugs administered?
Given orally with dose titration
What are the side effects of SA node blockade drugs?
Visual aura
Bradycardia
What other therapies are there for heart failure?
- Cardiac Resynchronisation Therapy (CRT)
- Implantable Cardioverter Defibrillator (ICD)
- Dialysis & Ultrafiltration
- Ventricular Assist Device (LVAD/RVAD)
- Intra-aortic balloon pump
- Cardiac transplantation
- (Stem cell therapy)
How does biventricular pacing work?
Biventricular pacemakers have an additional third lead designed to conduct signals directly into the left ventricle. Combination of all three leads promote synchronised pumping of ventricles, increasing efficiency of each beat and pumping more blood on the whole.
How do pacemakers work?
Standard pacemakers equipped with two wires (or “leads”) conduct pacing signals to specific regions of heart.
Complete the diagram of the pacemaker leads

Complete the diagram of the pacemakers
