Heart failure Flashcards
What is heart failure?
Occurs when the heart can not maintain an adequate cardiac output to meet the demands of the body
This results from any structural or functional abnormality that impairs the heart’s function
Name the 2 types of heart failure
Low output
High output
Name examples of low output heart failure
Systolic heart failure
Diastolic heart failure
What is high output heart failure?
Heart functions normally but demands of body is increased beyond what the heart can supply
Name causes of high output heart failure
Thyrotoxicosis
Profound anaemia
Pregnancy
Pagets’ disease
Acromegaly
Sepsis
Define systolic heart failure
Progressive deterioration of myocardial contractile function
Name causes of systolic heart failure
Ischaemic injury
Volume overload
Pressure overload
Define diastolic heart failure
Inability of heart chamber to relax, expand and fill sufficiently during diastole to accommodate an adequate blood volume
Name causes of diastolic heart failure
Significant left ventricular hypertrophy (i.e., lumen severely narrowed)
Infiltrative disorders
Constrictive pericarditis
Restrictive cardiomyopathy
Name cause of heart failure (overall)
Coronary heart disease
Hypertensive heart disease
Valvular heart disease
Myocardial disease/cardiomyopathies
Congenital heart disease
Define cardiomyopathy
Diffuse disease of heart muscle leading to functional impairment
What are the different types of cardiomyopathy?
Dilated
-various causes (50% familial)
-ETOH, pregnancy, systemic diseases (e.g., SLE), drug toxicity, myocarditis
Hypertrophic cardiomyopathy
-hereditary
Restrictive cardiomyopathy
-Rare
-amyloid is main cause in the UK
What is the pathophysiology of heart failure?
Pump failure = ↑SV and ↓CO
This starts compensatory mechanisms
Frank Starling mechanism = vasoconstriction, ↑venous return to heart, increased preload, heart muscle fibres stretch, enhanced contractility
Myocardial structural change = augment muscle mass +/- cardiac chamber dilation
Activation of hormonal system
-noradrenaline relase = ↑HR + ↑myocardial contractility (causes vasoconstriction)
-BNP/ANP release
-Activation of RAAS
How can compensatory mechanism worsen heart failure?
Vasoconstriction
-↑ resistance against which heart has to pump = ↓CO
Na + H2O retention
↑fluid = ↑ preload - if stretch too much ↓ contractile strength and CO
Excessive tachycardia
↓diastolic filling time = ↓ventricular filling = ↓SV and ↓CO
True or False
Chamber dilation happens in both pressure and volume overload
FALSE
Chamber dilation happens in volume overload - the muscle mass and thickness are increased in proportion to chamber diameter
Augmentation of muscle happens in pressure overload (e.g., left ventricular hypertrophy)
What are the clinical types of HF?
Left vs right sided
Acute vs chronic
Compensated vs decompensated
What is left-sided HF?
Failure of left side of heart
Blood backs up from heart to pulmonary circulation
What are the causes of left-sided HF?
Ischaemic heart disease
HTN
Valvular heart disease
Myocardial disease
What are the complications of left-sided HF?
Lungs - pulmonary oedema. Presents with:
-breathlessness
-orthopnoea
-paroxysmal nocturnal dyspnoea
Kidney
↓renal perfusion = RAAS activation = retention of salt + water
Brain - hypoxic encephalopathy. Presents with
-irritability
-loss of attention
-restlessness
-stupor or coma
What is right-sided HF?
Usually a consequence of left-sided HF (together they are called congestive heart failure)
NOTE: CCF can also be due to the same pathological process happening on each side of the heart
What is cor pulmonale?
Right-sided HF due to pulmonary HTN/increased resistance in pulmonary circulation
Usually due to respiratory disease e.g., COPD or pulmonary emboli
Name other causes of right-sided HF
Valvular heart disease
Congenital heart disease
What are the systemic effects of right-sided HF?
Liver and portal system
-congestive hepatomegaly
-centrilobular necrosis (when severe)
-cardiac cirrhosis
Spleen
-congestive splenomegaly
Abdomen
-ascites (accumulation of transudate in peritoneal cavity)
Subcutaneous tissue
-peripheral oedema (esp. ankle and preitibial)
-sacral oedema is bed-ridden
Pleural and pericardial space
-effusions
What are the clinical presentations of HF?
Orthopnoea
Paroxysmal nocturnal dyspnoea
Oedema
Hepatic congestion
Ascites
Fatigue
Weakness
What are the New York Heart Association (NYHA) classifications of HF?
Class I = no limitations of physical activity
Class II = slight limitation of ordinary activity
Class III = marked limitation, even during less than ordinary activity
Class IV = severe limitations with symptoms at rest
What are the clinical signs of HF?
Tachypnoea
Crackles/reduced breath sounds on auscultation
Cool peripheries
Cyanosis
Elevated JVP
Third heart sound (S3) - gallop rhythm
Displaced apex - LV enlargement
Peripheral oedema
Ascites
Hepatomegaly
True or false
Acute pulmonary oedema is a medical emergency
TRUE
The signs are:
Acute breathlessness
Pallor
Cyanosis
Sweating
Rapid pulse
Hypoxia
Crackles in lungs
Name clinical investigations for HF
Bedside -ECG
Bloods - baseline + BNP
Imaging
-CXR (check for cardiomegaly)
-Echocardiogram/
-Cardiac MRI/CT/CT.PET
-CTCA/coronary angiography
What are the current drug treatments for AF
ACEis/ARBs
ARNI
Aldosterone antagonists - e.g., spironolactone, eplerenone
Beta-blockers
SA node blockade - e.g., Ivabridine
Diuretics
-loops e.g., furosemide
-thiazides e.g., bendroflumethiazide
-quinazolines e.g., metolazone
Digoxin
-↑ cardiac motility
-slows conduction at AV node
-excreted by kidney
What is the immediate treatment of acute pulmonary oedema?
High flow O2
IV morphine
IV nitrates
IV furosemide
What is the definitive treatment of acute pulmonary oedema?
Identify causes
Oral diuretics
Medical therapy
Revascularisation (if appropriate)
Which drugs should not be used in heart failure? Why?
CCBs
depress heart function further and exacerbate symptoms
Which CCB can be used in HF? Why?
Amlodipine
Does not affect the myocardial contractility
Sources
https://bnf.nice.org.uk/treatment-summaries/calcium-channel-blockers/#:~:text=Amlodipine%20and%20felodipine%20also%20resemble,clinical%20deterioration%20in%20heart%20failure.
