chronic heart failure Flashcards
Different types of heart failure?
Systolic: related to the ventricle being unable to pump blood into the systemic/pulmonary system.
Related to small stroke volume
Diastolic: related to the ventricles not being able to fill.
Related to a reduced Total volume
Causes for systolic heart failure?
- Myocardial ishchaemia due to Atherosclerosis of the vessels supplying the heart- reduced delivery of 02 to the heart- leads to damage to the myocytes so they contract less
- valve disease: regurgitation or stenosis
- chronic hypertension: increased pressure of the atria- causes the ventricles to need more force to contract-can lead to hypertrophy- this increase 02 demands. hypertrophy also causes the coronary arteries to be squished which reduces 02 supply
- dilated cardiomyopathy- increased filling initially would lead to thinning of wall- with added contraction would lead to weakening of wall
Causes for diastolic heart failure?
- Concentric hypertrophy- less room for blood to fill in
- Aortic stenosis
- Restrictive cardiomyopathy- leads to reduced elasticity-heart cannot stretch out as much and fill with blood
What does heart failure lead to?
Reduced blood to the kidneys
This triggers the RAAS system fluid retention in vessels
Fluid can leak from blood vessels into tissues which leads to pulmonary oedema and ruptures
Signs
Crackles Elevated JVP 3rd heart sound Tachycardia- heart beats faster as it tries to compensate Displaced apex beat
Symptoms
SOB- dyspnea and orthopnea
Fatigue
Oedema
Reduced exercise capacity
Risk factors
Male Smoker Diabetic Previous MI Congenital heart disease Hypertension
Investigations
ECG- if normal then Left ventricle systolic dysfunction is unlikely
B- natriuretic peptide test- usually high in heart failure
LVEF: can be calculated using the Simpson or m-mode
ON ECHO:
-cardiomegaly
-pericardial oedema
-pleural effusion
LVEF in heart failure
Could still be normal even if heart failure is present.
In diastolic heart failure Total volume in the heart is reduced and therefore the stroke volume so their ratio might be similar to what it is in a normal heart
What do heart failure treatments target?
1- RAAS system inhibition 2- Sympathetic system inhibition 3- ANP/BNP enhancement 4- cardiac function enhancement 5-anticoagulation: warfarin
RAAS system inhibition drugs
1- Loop diuretics: removes XS salt and encourages diuresis. ADRs include gout, hypokalaemia, dehydration, hypotension, diabetes
2- ACE inhibitors: ADRs include: hypotension, hypokalemia, oedema, cough
3- ARBs
4- ARNIs
5-Aldesterone antagonists
Sympathetic system inhibitor drugs
1- Beta blockers- lead to vasodilation
Should only be used when patient in recovery stage- not acute stage
2-Ivabradine- usually used in conjunction with beta blockers
Cardiac function enhancement drugs
1- vasodilators
3-positive inotropes e.g. DIGOXIN
increase calcium content in myocytes
Main loop diuretic and what can it be used in association with
FUROSEMIDE
main ACE inhibitor
RAMIPRIL
