Cardiac Failure Flashcards
Types of heart failure
Chronic heart failure
Congestive heart failure
Congestive cardiac failure (CCF)
Causes of heart failure
Failure of the heart muscle or failure of heart valves
Often secondary
- IHD (most common)
- Hypertension
- Cardiomyopathies
Risk factors of cardiac failure
Pregnancy Anaemia Hyper & hypothyroidism Fluid retaining drugs: - Glucocorticoids - NSAIDs
What factors make up cardiac output
Preload
Afterload
Muscle contractility
Effect of hypertension on heart function
Increase in afterload causes hypertrophy; an increase in heart size makes it less efficient and lessens the ejection fraction
Ejection Fraction
Fraction of blood ejected per cardiac cycle
Used in diagnosis of heart failure
What happens as cardiac circumference increases
The heart has to work harder to get blood pumping around the body
Neurohormonal adaptation to compensate for circulatory failure
Sympathetic nervous system compensates, making things worse
Renin-angiotensin-aldosterone system
ADH
Atrial Natriutetic peptide (ANP)
Only mechanism that doesn’t make anything worse
ACE-I vs ACE-II
ACE-I converts Angiotensin I to A II
ACE-II converts A II to angiotensin 1-7
ACE 2 and Covid-19
ACE-2 is the spike protein receptor for the Sars-CoV-2 virus
It is present in lungs, heart, arteries, intestines, kidneys
Dangers of neurohormonal adaptations against cardiac failure
Increased afterload
Increased circulating volume (> pre and afterload)
Increased resistance will lead to impaired renal function; further activation of RAAS
Vicious cycle develops which further impairs the pump activity of hear and leads to myocyte dysfunction
Left sided heart failure
Often secondary to hypertension
LV gets impaired, building up pressure in LV and cardiac circulation
Leads to pulmonary oedema as pulmonary venous pressure increases which opposes reabsorption of fluid in lungs; fluid accumulates in lung tissue - Oedema
Right sided heart failure
RV output fails
Often due to
- lung disease (Cor Pulmonale)
- Pulmonary vavular stenosis
Biventricular failure
Both chambers
Disease (e.g. IHD gas affected both ventricles)
Or, LVF leads to pulmonary congestion, increasing load on right side, leading to right failure
Signs and Symptoms of Left Ventricle Failure
Pulmonary Oedema
Dyspnoea (breathlessness) - Sensation of drowning
Cough
Orthopnoea Breathless on lying which is relieved by sitting up
- Nocturnal problem?
Inspiratory Crepitations