Heart failure Flashcards
Define HF
clinical syndrome characterised by impaired cardiac pumping leading to the inability to pump blood and O2 to metabolising tissue despite normal filling pressures
What is ejection fraction (EF)?
Amount of blood pumped by the heart in one contraction
What is congestive HF?
HF with fluid retention/congestion
What are the different classifications of HF?
Systolic -REF
Diastolic - PEF
Acute
Chronic
Explain systolic -REF
- LVEF less than 35%
- LV can’t contract so heart can’t pump enough blood out therefore blood can not get in
Explain Diastolic - PEF
- LVEF more than 50%
- LV cannot relax so heart can not fill with blood therefore blood can not get out
What is acute HF
- rapid onset of sudden cardiac decline
- Life threatening
what is chronic HF?
- slow/progressive cardiac decline
- usually due to chronic conditions such HPT and diabetes
Describe the pathophysiological mechanisms of HF-REF.
- cardio renal - Forward failure causes water retention and reduced blood flow
- cardio circulatory - forward failure results in peripheral vasoconstriction and increased PVR
- neurohormonal activation and cardiac dysfunction results in reduced cardiac out and BP which increases SNS, RAAS and ADH this leads to cardiac remodelling
Describe the effects of neurohormonal activation.
- activation of SNS increases HR, contractility and vasoconstriction - increased catecholamines leads to ischaemia and cardiac remodelling. the increased renin activates RAAS.
- RAAS activation increases Ang II which increases vasoconstriction, SNS activation and cardiac remodelling. it increases aldosterone which leads to water and Na+ retention
- increases ADH increases water retention and vasoconstriction
What are the congestive symptoms of HF
Sacral/ankle oedema, productive cough, SOB/breathlessness and unable to lay flat
what are the hypo perfusion symptoms of HF?
decreased exercise tolerance, cold hands and feet and fatigue
What are the non-pharmacological treatments for chronic HF and state examples
Lifestyle modifications - increase activity to min 30mins a day, lose weight if needed, smoking cessation, alcohol moderation, decrease salt intake in diet, reduce fluid intake
Surgical - heart transplant.
Describe the current drug management treatment pathway for chronic HF/HF-REF. Give examples of drugs
- Diuretics e.g. Furosemide for water retention
- 1st line - BBs and ACEI/ARB e.g. atenolol and lisinopril/candesartan
- aldosterone -RA e.g. spironolactone
- ARNI e.g. Sacubitril/Valsartan - must STOP ACEI/ARB
- If channel inhibitor e.g. Ivabradine if resting HR > 75bpm
- Vasodilator e.g. Hydralazine/ISDN - this FIRST LINE if patient intolerant to AECI/ARB
- Inotropic agent e.g. digoxin
What is the mechanism of actions of Diuretics e.g.furosemide?
inhibit Na+/K+ exchange in DCT to promote diuresis which decreases plasma volume.
arterial and venodilation reduces preload increasing exercise tolerance and decreasing congestive symptoms