Heart Failure Flashcards
What is heart failure?
A clinical syndrome of ruduced CO, tissue hypofusion and increased pulmonary pressurs and tissue congestion (oedema)
What is the name for when both the left and right ventricles fail?
Congestive heart failure
What are the signs and synptoms of left sided heart failure?
- Fatigue
- Breathless (around exertion)
- Orthopnoea (shorting breath laying flat)
- Paroxysmal nocturnal dysponea (waking up breathless neeing fresh air)
- Basal pulmonary crackles
- Cardiomegaly (displaced apex beat)
What are the signs and symptoms of right sidede heart failure?
- Fatigue
- Breathless
- Pheripheral oedema (pitting)
- Raised jugular venous pressure
- Tender, smooth enlarged liver
What are the key presentations of a patient with heart failure?
Dysponea and fatigue (due to tissue hypofusion)
Increased fluid retention
LV failure= pulmonary, RV failure= peripheral
What causes heart failure?
Remodelling of cardiac muscle (loss of myoctes/ fibrosis) in response to changing ventricular function and shape/ size
Impairment of filling (decreased chamber size)
Impairment of ejection (decreased contraction)
What are common causes of heart failure?
Isceamic heart disease
Hypertension
Valvular disease
(Other)
What is a less common cause of heart failure?
High output failure
Increased demand on cardiac output NOT heart function decreasing
Eg, Sepsis
How is heart failure caused by ejection problems?
Contractility effected in systolic
Heart cant pump with enough force
Space available for filling NOT reduced just can’t empty ventricles
How is heart failure caused by a filling problem?
Less blood into ventricles in diastole
Volume available for blood to fill ventricles is reduced
End diastolic volume decreased
What results in ejection problems?
Muscle walls fibrosed
Chamber spaced enlarged (overstretched)
Abnormal myocyte contraction
What results in Filling problems?
Chambers stiff
Ventricular walls thickened
How to tell the differnece between ejection/ filling problem?
SV/ EDV= ejection fraction (EF)
If less than 50%= ejection (HFrEF)
If normal= filling (HFpEF)
EDV=end diastolic volume
HFrEF= heart failure with reduced ejection fraction
P= preserved
How can a preserved ejection fraction cause heart failure?
The contraction is not impaired so 50% of ventricle volume is still ejected but this is a small CO as origionally filled less
How can you determine between if heart failure if HFeEF or HFpEF?
Carry out an echocardiogram
What is the normal relationship between CO and end diastolic volume?
As EDV increases so does CO
Up to a certain point the CO dips
What allows CO to increase with EDV?
Properties of cardiac myocytes
- more stretch in ventricle during diastole= greater SV ejected in systole
- more myocytes stretched harder they contact
How does EDV and CO relationship different in a patient suffering from LV systolic heart failure?
Increased filling in failing heart = little increase in CO
(Eventually worsening CO)
Large increases in EDV (to try and increase SV) lead to reduced CO and pulmonary oedema
How does the RAAS system contribute to heart failure?
Worsens the heart failure by increasing the cardiac work load
Has cardiotoxic effects from long term activation of sympa system and angiotensin 2
How does the RAAS increase workload on the heart?
Increased the preload (larger EDV)-increased circulating blood volume by stimulating ADH
Increases the afterload- enhances sympathetic activity
-vasoconstriction
How does the sympathetic nervous system respond to heart failure?
Increases cardiac demand
In response to lower CO and BP, increased sympa drive
Increased afterload
How does pulmonary oedemas develop?
Increased pressure in LV (failure in ejection)
Increased pressure in pulmonary circulation (backtracks)
Increased pres at venuole end of cap bed
Less favourable hydro/oncotic press gradient
Increased fluid accumulation
How do peripheral oedemas develop?
Increased pressure in RV (ejection failure)
Increased pressure in systemic circulations
Increased CVP= increased jugular VP
Unfavourable hydro/oncotic gradient at venule end cap beds
Increased volume of tissue fluid= oedema
What drugs reduce CO and therefore reduces workload of the heart?
B-blockers (reduce BP and CO)
ACE inhibitors (stop effects of angiotensin 2)
Diuretics (reduce blood volume)
Ca channel blockers (reduce peripheral vasoconstriction)
Nitrates (vendodilation)
