CHF Flashcards
What is heart failure?
disorder in which the heart pumps blood inadequately, leading to reduced blood flow and back up of blood in the veins and lungs.
What are the two types of heart failure?
systolic: heart contracts less forcefully and cannot pump out as much of the blood that has returned to it, as aresult more blood remains in the ventricles,
- diastolic dysfunction: heart is stiff and does not relax normally after contracting. Can pump a normal amount of blood out of the ventricles the stiff heart does not allow as much blood to enter its chambers from the veins.
Sx of CHF
- cough*
- tiredness, SOB
- pulmonary edema
- pulmonary effusion
- ascites
- peripheral edema
What is the number risk factor of CHF? What are some other risk factors for heart dz?
-ischemic heart disease
Other key factors:
- high blood pressure
- high LDL
- smoking
- diabetes
- obesity
- physical inactivity
- excessive alcohol use
Rare Causes of Heart failure
- viral myocarditis
- amyloidosis
- HIV cardiomyopathy
- SLE
- Drug and alcohol abuse (cocaine)
- chemi
- arrhythmias
- Obstructive Sleep apnea
What 4 things determine heart function?
- electrical system
- heart muscle excursion (ejection fraction)
- priming the pump (preload)
- resistance to ejection (afterload)
WHat is the difference between cardiac arrest and cardiac infarction?
cardiac arrest is the cessation of normal circulation of the blood due to failure of the heart to contract effectively.
Cardiac infarction is where blood flow to the muscle of the heart in impaired.
Pathophys of CHF
-reduced force of contraction d/t overloading of the ventricle.
WHat are the most common causes of systolic and diastolic dysfunction?
-coronary artery dz is more common cause of systolic dysfunction and HTN is most common cause of diastolic dysfunction.
Signs and Sx of CHF
- exertional dyspnea
- PND
- Orthopnea
- JVD
- Crackles
- Displaced apical impulse
- S4 & S3
How does the RAAS axis play a role in CHF?
- decreased renal blood flow secondary to low CO triggers renin secretion by the kidneys… Alodosterone release leading to increased Na+ and Water.
- preload increases…worsenijng failure. :(
what are the 4 main mechanisms that cause left sided heart failure?
- Impaired ventricular relaxation **
- Increased afterload (pressure overload)
- Volume overload (increased preload)
- Impaired contractility
Coronary Atherosclerosis how does this contribute to CHF?
-clogging of coronary vessels with fatty build up leading to inadequate oxygenation of the heart muscle leading to ischemia.
Damage to endothelial cells will lead to decreased NO & prostacyclin (vasodilator) and increased endothelin production (Vasoconstrictor) causing vasoconstriction, vasospasms, and thrombosis.
-Myocardial ischemia leads to diastolic dysfunction (relaxation impairment) and systolic dysfunction (contractility impairment)
Persistent High blood pressure, how does this contribute to CHF?
-when aortic diastolic blood pressure rises to 90mmHg or more the myocardium must exert more force to open the aortic valve and pump out the same amount of blood….myocardium hypertrophies, stress takes its toll and the myocardium becomes weaker.
What is the difference between concentric and eccentric hypertrophy ?
Concentric is hypertrophy of all areas of the ventricle, ventricle remains its relationship to the chamber size.
Eccentric: hypertrophy with ventricular dilation, cannot maintain its original shape and chamber size.