Heart failure as a drug target Flashcards
Define heart failure.
The inability of the heart to pump blood effectively around the body.
What are the possible causes of heart failure?
Ischaemic heart disease Hypertension Valve disease Cardiomyopathy Arrythmias
What are the symptoms of heart failure?
Shortness of breath
Fatigue and weakness
Swelling (oedema)
Explain systolic heart failure.
The left ventricle is unable to contract completely and pump enough blood forcefully throughout the body. There is a reduced Ejection fraction
What is Left sided heart failure?
It occurs when the left ventricle doesn’t pump efficiently preventing the body from getting enough oxygen.
This causes fluid build up in the lungs and causes pulmonary oedema.
What is Right sided heart failure?
Not enough blood being pumped into the lungs
What is congestive cardiac failure?
Failure of both sides of the heart.
Fluid build up around the heart
What are the signs and symptoms of Right sided heart failure?
Swelling (oedema) especially in the lower limbs Heavy painful legs Difficulty walking Skin infections Tiredness, light headed and fainting
What process is not functioning properly in Left-sided heart failure?
Systolic (pumping dysfunction)
Due to damage of the myocardium, unable to contract as forcefully and pump as efficiently
What is the most common cause of Left-sided heart failure?
Ischaemic heart disease - coronary artery atherosclerosis
What is the most common cause of Left-sided heart failure? (Explain)
Ischaemic heart disease - coronary artery atherosclerosis
less blood and O2 gets through the coronary artery to the heart tissue due to plaque buildup, causing damage to the myocardium
What happens if the coronary artery becomes completely blocked?
Can cause a heart attack and leave scar tissue of the myocardium resulting in its inability to contract at all
What is pitting oedema?
When a swollen part of the body has a dimple ‘pit’ after you press it for a few seconds.
How many stages are there of congestive heart failure?
4
State the two ways of measuring heart failure?
BNP
Echocardiogram
What is BNP?
Brain naturietic peptide
it is secreted by the cardiomyocytes in the ventricles as a response to stretch
What does a high BNP level indicate?
The severity of heart failure
correlated to the blood in ventricles
How can an Echocardiogram indicate heart failure?
Dilated left ventricle with a reduced ejection fraction
What is mitral regurgitation?
Leakage of blood backward through the mitral valve each time the left ventricle contracts
What is cardiomyopathy?
Disease of the heart muscle.
What is cardiac hypertrophy?
Abnormal enlargement, thickening of the heart muscle.
Filling of blood in the heart doesn’t occur properly.
What is preload?
The amount of stretch on cardiac muscles after diastole.
at the end of ventricular filling
What is the preload like during heart failure?
Elevated due to ventricular dilatation and increased blood volume
What drugs can be used to reduce preload?
Loop diuretics = furosemide
Aldosterone antagonists = Spironolactone
How do loop diuretics reduce preload?
Act on Na, K, 2Cl symporter in thick ascending limb of the loop of Henle.
How can aldosterone reduce preload?
It decreased sodium reabsorption in the vital loop and collecting duct
What is afterload?
The amount of pressure the heart has to contract to eject the blood during systole.
How can afterload be reduced?
antihypertensives
ACE inhibitors = ramipril
Calcium Channel blockers = Amlodipine
What is rate control?
Slowing down the heart to improve EF
What drugs can reduce the heart rate?
Beta blockers
Calcium channel blockers
What is rhythm control?
Improving heart efficiency can improve symptoms
What drugs can improve heart rhythm?
Beta blocker (1st line) Digoxin (add on)
