Pathophysiology of Heart Failure Flashcards
What is acute?
Sudden onset
What is chronic?
Secondary effects
What is biventricular failure?
BOTH chambers affected
What would be the ejection fraction for HF?
<40%
What are the clinical features of HF?
Hypotension
Reduced urine flow
Cold peripheries
Breathlessness
Oedema
Atrial fibrillation
Tiredness + dizziness
Why is there reduced urine flow?
Less blood flowing round body under lower pressure
Why is there breathlessness?
NOT enough blood to the lungs
Why is there oedema?
Lungs = fluid leaking
Peripheral oedema = ankles = in common in cardiac patients
What are the causes of left-sided HF?
Impaired contractility
Pressure overload
What are the causes of impaired contractility?
Myocardial infarction
Overstretched heart
= leaky valves
= mitral/aortic regurgitation
What is the cause of pressure overload?
Uncontrolled hypertension
What happens in left systolic dysfunction?
ESV increases
EDV increases
SV decreases
What causes left ventricular diastolic dysfuntion?
LV hypertrophy = thicker walls = stiffer = doesn’t fill with blood as easily
Myocardial ischaemia = stiff ventricular wall = starved of O = difficult to refill ventricle
What causes obstruction of LV filling?
Valve disease
= narrowed mitral valve = mitral stenosis = less filling of LV
Cardiac tamponade
What is myocarditis?
Inflammatory response = effects tissue function = produces fluid = oedema = squishes the heart
What happens in left diastolic dysfunction?
EDV decreases
SV decreases
What will vol overload result in?
Increase in EV, which will tigger Starling mechanism (=stretch)
What will a positive inotrope do?
Increase Ca2+
= more forceful contraction
What will ACEi do?
Reduce production of angiotensin II
What will beta antagonists do?
Decrease degree renin-angiotensin system switched on
What will spironolactone diuretics do?
Decrease fluid retention
What will venodilators do?
Reduce strain on heart
= preload
What will vasodilators do?
Reduce strain on heart
= afterload
What does the renin-angiotensin system do?
Helps to retain fluid (Na+) = increase BP
