Chronic Heart Failure Flashcards
Heart failure may be preciptated by
Pregnancy
Anaemia
Hyper&Hypothyroidism
Fluid retaining drugs: Glucocorticoids, NSAIDs
Systems involvde in neurohormonal adaptation to HF
- SNS
- RAAS
- ADH
- ANP - To Promote Sodium loss
Consequences of Neurohormonal adaptation to HF
- Increased afterload
- Incr circulating volume (Pre & afterload)
- Incr resistance will cause impaired renal function, more salt/water retention and further RAAS activation
- Vicious cycle develops impairing pump acvitity
LHF Cause & Consequence
- Often 20 to hypertension
- Poor output will lead to increasede in left atrial /pulmonary venous pressure with pulmonary oedema
Causes of RHF
- Lung Disease (cor pulmonale)
- Pulmonary valvular stenosis
Causes of biventricular failure
- Disease (e.g. IHD affecst both ventricels)
- LV failure leads to pulmonary congestion, which may lead to RV failure
LV failure S&S
Pulmonary oeodema
- Dyspnea
- Cough?
- Oorthopnea
- Insipiritory crackles
RV failure S&S
- Raised venuos pressure
- Raised VP
- Enlarged liver
- Oedema; ankles
Diagnosing HF
- Symptoms + Exminatin
- Confirmed by Echo: Ejectin fractin <45%
- BNP levels mya be diagnostic
- CXR: Cardiomegaly, PO, Kerely lines
Treatment aims in AF
Causes stasis of blood; risk of thrombi, TIA etc
- Thromboembolism prophylaxis: warfarin or Aspirin
Pharmacological management of HF
- Stage dependent
- All with LV systolic dysfunction:ACEI
- All w/ oedema: diuretic
- BB in first-line in moderate/stable heart failure
ACEI MOA in HF
Enalapril, Lisinopril, Ramipril
- Reduce arterial and venoous vasoconstriction
- Reducing after & preload
- Reduce Salt/water retnetiom; reduce circulating volume
- Inhibit RAAS, so oppose maladaption and remodelling
How to prescribe ACEis
- Low dose, titrate up, may exceed max dose
- DO NOT USE WITH NSAIDS
- Monitor: urea/creatinine, Potassium
- Avoid in hypotension <100 systolic
May cause severe hypo; withdraw for few days, give at night
May further deteriorate renal function
AT1 MOA, Indicationos
Candesartan, Losartan
- oppose ATII action at AT1 receptor
- Equakly effective as ACI
- No cough
When/which diuretics too use in HF
- Thiazides: Used in mild filaure or the elderly
- Loops: In pulmonary oedema
Reduce circulating volume = reduced Pre& after
Also vasodilate, reducing preload
Side effects of diuretics
Thiazides/loops may cause HYPOkalaemia; less of a problem when used with ACEi(cause HYPER)
Role of BBs in HF
Reduce diesease proogression, sypmtoms and mortality
- Reduce sympathetic stimulation, HR, and O2 consumption
- Also controls AF rate
- Oppose Neurohormonal adpatastions that cause myocyte damage
- Especially useful when there is ischamiea
- Start low, work up. may get worse first
- May be used in caution with COPD
Role of spironolactone in HF
- Aldosterone receptor antagonist
- Reduced LV hypertrophy
- Low dose 25mg reduced mortality 35%
Digoxin MOA in HF
- Inhibits Na/KATPase. NA accumulates in myocytes, exchanged with Ca; increased contractility
- Imapirs AV conduction and increases vagal actviirty
- this block and brady is useful in HF with AF
CONTRAINDICATED IN CONCURRENT HEART BLOCK R BRADYCARDIA. So generally reserved for HF with AF. Titrate so HR >60
Renal function monitoring in HF drugs
- Digoxin reduced in renal impairment, due to being “/rds renally excreted
- Thiazides ineffective in renal failure
- ACEIs; used with care in mild-moderate failure but monitored
- Contraindicated in renovascular disease(stenosis)
Potassium considerations in HF management
Hypokalaemia from thiazides/loops
- Enhances effect of digoxin
- Seriours possibility of HYPERkalaemia if ACEi used with K+ sparing diuretic
Digoxin toxicity in HF
Narrow therapeutic window
- Anorexia and nausea suggest too high dose + visual disturbances, diarrhoea
- monitor HR >60 in AF
Treatment algorithm in HF
