Heart Failure Flashcards
List some possible causes of heart failure
IHD (primary cause) Hypertension Dilated cardiomyopathy -alcohol/drugs/poisoning/pregnancy/infections Valvular heart disease Congenital HD Restrictive cardiomyopathy Pericardial disease Arrhythmias
How is heart failure classified?
Class 1= not symptomatic but at high risk
Class 2= slight limitation of physical activity, no symptoms at rest, some on exertion
Class 3= marked limitation of physical activity, no symptoms at rest, symptoms appear with minimal exertion
Class 4= inability to carry out activity without symptoms, symptoms at rest.
What structural changes does the heart undergo in HF?
Loss of muscle
Changes to the EMC: increased cartilage, slippage of myocardial fibre orientation
Myocytolysis and vacuolation of cells
Myocyte hypertrophic
SR disfunction, changes to Ca availability
What are the signs and symptoms of left HF?
Fatigue Exertional dyspnoea Paroxysmal nocturnal dyspnoea Tachycardia Cardiomegaly 3rd or 4th heart sound Functional murmur of mitral regurgitation Basal pulmonary crackles Peripheral oedema
What can cause right HF?
Most commonly occurs secondary to left HF
Chronic lung disease
Pulmonary embolism
Pulmonary Hypertension
Pulmonary valvular disease
Left to right shunts
Isolated right ventricular cardiomyopathy
What are the signs and symptoms of right HF?
Fatigue Dyspnoea Anorexia Nausea Tender, smooth hepatic enlargement Putting oedema Ascites Pleural effusion Raised JVP
What neuro-hormonal effects does heart failure have?
Sympathetic NS activation
Renin-Angiotensin-Aldosterone-System activation
Natriuretic hormone activation
Anti-diuretic hormone activation
What effect does the sympathetic nervous system have in HF and how is it activated?
Baroreceptor mediated.
Early compensatory mechanism to improve CO, (contractility, tachycardia & vasoconstriction)
But has long term deleterious effects (increases workload, increased BP, cardiac hypertrophy, myocyte apoptosis, reduction in HR variability)
What effect does the Renin-angiotensin-aldosterone system have in HF and how is it activated?
Drop in BP stimulates renin release from kidneys, this converts Angiotensin to Angiotensin I, ACE converts this to Angiotensin II.
Angiotensin II = vasoconstrictor, promotes aldosterone release (increases Na and water retention, increases blood volume), promotes LVH.
What effect do natriuretic hormones have in HF and how are they activated?
Atrial: vasodilator, decreases Na reabsorption, inhibits renin and aldosterone secretion. Activated through atrial and ventricular stretching.
Brain: has similar affects, activated through ventricular stretching
Acts as a marker for heart failure
What effect does ADH have in HF and how is it activated?
Acts on V2 receptors in the collecting duct to increase H2O retention, causes tachycardia and reduced systemic resistance, resulting in increased CO.
Activated in HF due to reduced arterial pressure
What effect does HF have on vascular endothelium?
Increased in peripheral arterial resistance due to increased SNS, RAAS
What skeletal muscle changes occur in HF?
Reduced blood flow
Reduced muscle mass (cachexia), affects limbs and respiratory muscle.
Contributes to fatigue and exercise intolerance
What effects does have HF on the renal system?
Increased Na and H2O retention
In severe HF, GFR reduces causing a rise in serum urea and creatinine.
What is diastolic heart failure?
Normal LV function but impaired diastolic LV filling leading to a reduced cardiac output.
What are the main principles in the management of heart failure?
Correct the underlying cause
Take non-pharmacological measures
Use pharmacological therapy to improve symptoms, delay progression and reduce mortality.
Treat complications/CVS risk factors
What lifestyle modifications can be made in the management if heart failure?
Reduced salt intake
Reduced alcohol
Increased exercise
Reduced blood pressure
Define heart failure
A state in which the heart fails to maintain an adequate circulation for the needs of the body, despite an adequate filling pressure.
What drugs are used to treat HF?
B-blockers ACE-inhibitors Diuretics Organic nitrates Cardiac glycosides
