Heart failure Flashcards
What is heart failure?
= inability of the heart to pump sufficient blood to meet the metabolic needs of the tissues of the heart, in the presence of adequate filling pressure
Causes of heart failure?
- ischemic heart disease
- hypertension
- myocardial infarction
- heart valve disease
What is systolic heart failure? (Left)
= heart failure with reduced systolic function
- muscle isnt pumping hard enough (unable to pump with enough force)
- impaired pumping ability of ventricle leading to reduced cardiac output
What is diastolic heart failure?
= heart failure with preserved systolic function
- ventricle becomes thick with stiffened walls and small cavity
- relaxation and ventricle filling impaired (unable to relax to allow normal filling)
- ejection fraction is normal but cardiac output is decreased
Preload vs Afterload
preload = Initial stretching of the heart muscle prior to contraction (prior to filling)
Afterload = force or load against which the heart has to contract to eject the blood
What happens to other systems with systolic heart failure?>
when the heart begins to fail many systems are brought into play in the attempt to maintain the cardiac output including:
- renin-angiotensin-aldosterone system
- sympathetic nervous system
- endothelium, vasopressin, atrial natriuretic peptide (ANP)
What is the non- pharmacological treatment for heart failure?
- pt eduction
- weight loss
- regular exercise
- sodium restriction
- avoid smoking
- alcohol restriction
What is the pharmacological treatment for heart failure? ABCDD
- ACE inhibitors (first line)
- Angiotensin II receptor antagonists
- Neurolysin inhibitors
- Diuretics
- Beta blockers
- Spironolactone
- Ivabradine
- Digoxin
How does angiotensin converting enzymes affect heart failure?
- decrease angiotensin II levels
- increase bradykinin levels
- produce vasodilation
- increase excretion of sodium and water
- reduce preload and after load
- slow progression of heart failure
ACE inhibitors MOA?
= Block the conversion of angiotension I to angiotension II
- inhibit breakdown of bradykinin
- reduce angiotensin II levels (inhibit production)
e.g. ramipril
MOA of beta blockers?
= completely block receptors in heart ect
- increase BP
- decrease HR
- Decrease contractibility
Adverse reactions of beta blockers?
- bradycardia
- hypotension
- depression
- insomina
- hepatotoxicity
Contraindictions of beta blockers?
- shock (cardiogenic)
- hyperthyroidism
- history of anaphylactic
- diabetes
Interactions of beta blockers?
- may cause asthma attacks as not selective
MOA of neurolysin inhibitors
= inhibits neprilysin decreasing degredation of natriuretic peptides
- increase angiotensin II
- vasodilation, increase GFR and increase bradykinin
