Flashcards in CHF Deck (26)
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
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
-excessive alcohol use
Rare Causes of Heart failure
-Drug and alcohol abuse (cocaine)
-Obstructive Sleep apnea
What 4 things determine heart function?
-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
-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?
1. Impaired ventricular relaxation ****
2. Increased afterload (pressure overload)
3. Volume overload (increased preload)
4. 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.
Dilated Cardiomyopathy, how does this contribute to CHF?
-ventricles stretch and become flabby, the myocardium deteriorates.
-cause is unknown, may be drug toxicity, hypothyroidism, and inflamm of the heart.
*the hearts attempts to work harder result in increasing levels of Ca2+ in the cardiac cells which activates a calcium sensitive enzyme tha switches on a gene causing heart enlargement.
*ventricular contractility is impaired, CO is poor and the condition progressively worsens.
briefly describe the three types of cardiomyopathy.
-dilated: ventricles enlarge and impair systolic function. Progressive LVE.
hypertrophic: walls of ventricles become thick and impair diastolic relaxation, rise in LV pressure is transmitted backwards leading to elevated left atrial pressure and pulmonary pressure.
restrictive: walls of ventricles become stiff and thick d/t fibrotic dz.
Right Heart Failure
-Pulmonary disease (COPD, fibrosis, HTN)
-Cardiac disease of both ventricles
-decreased right sided cardiac output or increased pulmonary vascular resistance leading to increased right ventricle pressures. As pressure rises in the right atrium and venous system there will be higher JVP.
-reduced stroke volume and incerased ESV d/t reduced ventricular excursion.
-decreased EDV from impaired ventricular filling
-enlargement of the ventricles contribute to the spherical shape of the heart.
PE findings of Right Heart Sided Failure
All d/t backward failure of the right ventricle leading to congestion of systemic capillaries.
-pitting peripheral/sacral/thighs edema(anasarca)
-liver congestion = jaundice & coagulopathy
What gives you the best estimate clinically of right arterial pressure and right side function?
Jugular venous pressure
abnormal if greater than 3cm above sternal notch.
Left Sided Heart Failure
-signs and sx
Signs and sx:
-congestion of the pulmonary vasculature. Can be subdivided into failure of the left atrium, left ventricle or both within the left circuit.
failure of the pump function of the heart is characterized by a decreased EF of _____%.
Describe the New York Heart Association Function CLassification of CHF
I.) no limitations of activity, ordinary activity does not cause fatigue, palpitations, dyspnea, or anginal pain
II.) slight limitations of activity, asymptomatic at rest, ordinary activity results in fatigue, palpitations, dyspnea or anginal pain
III.) Marked limitation of activity, usually asymptomatic at rest, less than ordinary activity causes fatigue, palpitations, dyspnea, or anginal pain
IV.) Inability to carry on any physical activity w/o discomfort, sx at rest, increased discomfort with any physical activity
American College of Cardiology/American heart association classification of CHF
Stage A. high risk for developing heart failure in the future but no functional or structural heart disorder
Stage B. structural heart disorder but no sx at any stage
Stage C. previous or current sx of heart failure in the context of underlying structural heart problem but managed with medical treatment.
Stage D Advanced dz requiring hospital based support, a heart transplant or palliative care.
Tx Diastolic heart failure
-salt and water restriction
-blood pressure control