Congestive Heart Failure Flashcards
What does congestion refer to?
pooling of blood within blood vessels
Is congestive heart failure a disease?
No - it is a condition, a group of manifestations related to disease of the heart.
What are risk factors for congestive heart failure?
- MI
- cardiomyopathy
- excessive cardiac workload
- valvular disease
- hypervolemia
- uncontrolled hypertension
most important targets for prevention, list from Porth:
- hypertension
- ischemic heart disease
- hyperlipidemia
- smoking
What is the pathology of left-sided heart failure?
- left ventricle doesn’t eject sufficient volume
- leads to residual volume in the left ventricle
- causes the left atrium to pump harder to empty blood into the left ventricle
- the left atrium fails to empty fully
- causes the left atrium to be unable to receive pulmonary return
- causes pulmonary congestion and edema (increased hydrostatic pressure due to congestion causes fluid to move out of blood vessels)
- causes the right ventricle’s workload to increase
- leads to hypertrophy in the right ventricle
- right ventricle failure usually follows left ventricle failure
What is the pathology of right-sided heart failure?
- failure to pump into the pulmonary circuit
- causes residual volume in the right ventricle
- causes residual volume in the right atrium
- causes congestion in the systemic circuit
- causes peripheral edema and abdominal organ distention
What are the manifestations of right-sided heart failure?
- peripheral edema
- ascites
- abdominal organ distension (anorexia, GI distress, weight loss, signs of impaired liver function)
What are the manifestations of left-sided heart failure?
- pulmonary edema (orthopnea, cough with frothy sputum)
- decreased activity tolerance and signs of decreased tissue perfusion (from decreased cardiac output)
- cyanosis and signs of hypoxia (pulmonary congestion causes impaired gas echange)
What is compensated heart failure?
heart failure with compensation, clinically asymptomatic since it is successful initially
List the six compensations that occur in heart failure.
1) ventricle dilation (Frank-Starling law)
2) sympathetic nervous system
3) RAAS
4) natriuretic peptides
5) endothelins
6) cardiac hypertrophy and remodelling
How is congestive heart failure diagnosed?
- history (look for risk factors) and physical exam
- labs (CBC to look for anemia, liver function tests because if there is liver distention it won’t work as well)
- ECG
- echocardiogram
How is congestive heart failure treated?
complex and will vary from patient to patient
1) avoid death and manage acute symptoms, stabilize and correct cause
2) chronic management
- manage symptoms
- decrease risks (stop smoking)
- increase heart function
3) if systolic heart failure (ejection fraction under 40%, give ACEI or beta blocker
4) if ejection fraction is equal or over 40%
- treat the cause
- give ACEI or ACEI and beta blocker
- angiotensin receptor blocker (if symptomatic with activity) is added to above
- may need to increase dose or add diuretic if symptomatic at rest
5) surgery to repair a defect
Explain how ventricle dilation works to compensate for heart failure.
the more a ventricle is stretched, the more it will fill, the more it will empty, thus increasing cardiac output
Explain how the sympathetic nervous system works to compensate for heart failure.
the SNS aims to increase CO by:
- vasoconstriction of peripheral vessels (increases peripheral resistance to increase blood pressure)
- tachycardia (increases heart rate to increase cardiac output)
- increase contractility
Explain how the RAAS works to compensate for heart failure.
- decreased cardiac output causes decreased renal perfusion
- RAAS triggered
- release of renin
- triggers angiotensin 1
- converted to angiotensin 2 by ACE
- angiotensin 2 triggers release of aldosterone
- causes sodium reabsorption, water follows to increase blood volume
- increases preload to increase cardiac output
Explain how natriuretic peptides work to compensate for heart failure.
- atrial natriuretic peptide and brain natriuretic peptide made by the heart
- bring about diuresis (removal of fluid) and naturesis (removal of sodium)
- opposite of RAAS
- also impacts smooth muscle in vasculature, causes dilation to decrease pressure
