describe CHF
- A chronic condition in which the heart is unable to pump enough blood to meet the body’s needs
- This happens when other conditions have damaged the ventricle resulting to either weakening of the muscles or the muscles becoming too stiffed
describe preload
Volume of blood in heart at the end of diastole, blood that enters the RA from the IVC & SVC
describe afterload
Amount of resistance that the ventricle must overcome in order to pump blood out of the heart
- Increased arterial vascular resistance (vasoconstriction) creates elevated afterload
- drugs like ACEi, diuretics
= decrease afterload
risk factors of CHF (6)
- Hypertension
- High BP- > increased workload of the heart (think of the afterload!)
- Coronary Artery Disease
- Lead to decreased perfusion of heart muscles
- Heart Attack or MI
- Lead to weak heart
- Arrhythmias
- Irregular heart rhythm, increased heart rate, or very low heart rate = decreased cardiac output
- Valvular heart diseases (mitral and tricuspid valves)
- Weakening of the heart muscles by: viruses, chronic alcoholism, obesity, or drugs (toxic effect)
describe the pathway of valvular hear diseases
- Weakened valves
- when LV contracts = some blood returns back to LA
a) decreased amount of blood that goes to the aorta
= decreased cardiac output
b) LA pressure increases -> increased pressure to pulmonary vein
= fluids diffuse to lungs = SOB
what are the 2 types of CHF
- left-sided heart failure
2. right-sided heart failure
describe the pathway of left-sided heart failure
- Increased afterload
- LV has to work harder
- LV hypertrophies / eventually weakens
- backward effect = LA affected
- pulmonary veins affected
- lungs are filled up with fluids
= SOB
LHF = L for Lungs
describe the pathway of right-sided heart failure
- RV affectation
- fluids back up to RA
- further backs up to SVC and IVC
= generalized edema
RHF = R for Rest of the body
what is the leading cause of left-sided heart failure
HTN is the leading cause of left-sided heart failure
s/s of CHF
- SOB
- Easy fatiguability, body weakness
- Edema
- Persistent cough or wheezing; crackles
- Rapid weight gain = 1 L of fluid = 1 kg of weight gain
diagnostic tests to diagnose CHF
- BNP: substance produced by the heart and released when heart muscles are stretched out
- Ejection Fraction: percentage of blood ejected every time it contracts, 65% and above is normal!
- below 65% = heart is not pumping properly - Radiographic study of the chest to look for cardiomegaly
