Heart Failure Flashcards
What is heart failure?
Cardiac function is insufficient to pump blood at the rate required by tissues
What is the ultimate cause of heart failure
Myocardial tissue failure
What are the 3 characteristics of heart failure?
Reduced exercise tolerance
High incidence of ventricular arrhythmias
Shortened life expectancy
What are some of the main causes of heart failure?
CAD
HTN
Dilated cardiomyopathies
Valvular disease (stenosis/regurg cause bad filling or emptying)
Myocarditis (infection)
What is a normal ejection fraction?
More than 50%
What kind of ejection fraction do peopel with heart failure have?
<40%
Why do the ventricles dilate in heart failure?
A bigger volume of blood will help the heart move up the frank starling curve, so the body tries to exploit this by making the ventricles bigger
What happens to resting stroke volume in heart filaure?
Decreases
Duh
What happens to cardiac index in heart failure?
Reduces. Pt can no longer sustain enough CO to do their normal activities.
What happens to contractility in heart failure?
It is deficient. The person can no longer respond efficiently to increases in preload (EDV)
What are some of the cellular causes of heart failure?
Impaired calcium usage
Changes in ATP production/usage
What is diastolic heart filaure?
Impaired filling
Impaired ventricular hypertrophy
What usually causes right-sided heart failure?
Left sided heart failure
What is systolic heart failure?
Diminished capacity to eject blood due to loss of contractility or high afterloads (HTN, aortic stenosis)
What are the causes of impaired contractility?
Myocardial infarction
Transient myocardial ischemia
Chronic volume overload (mitral/aortic regurg)
Dilated cardiomyopathy
What kinds of things can cause diastolic dysfunction?
- Impaired ventricular relaxation- LV hypertrophy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, transient ischemia
- Obstruction of LV filling- mitral stenosis, cardiac tamponade
In left sided heart failure, what happens to the pressures in the L atrium and the pulmonary vasculature?
Pressures increase due to the activity of the right heart
Can Left sided heart failure cause pulmonary edema?
Yes
Is it hard to overload the right side of the heart>?
No, it is a low-pressure system and is easy to overload
Is pulmonary hypertension always caused by left heart failure?
No it can be caused by poor lung function, which then causes R sided heart failure (cor pulmonale)*****
What is jugular vein distention caused by?
Right sided heart failure
Why would right sided heart failure cause peripheral edema?
Rise in venous pressures increases capillary pressures, which favors filtration!!!!!!!!!!***
What are some of the compensatory mechanisms for heart failure?
Frank starling mechanisms (increased ESV)
Ventricular remodeling
Neurohormonal activation (adrenaline, renin-angiotensin, ADH/vasopressin)
What are the two types of ventricular hypertrophy?
Concentric hypertrophy
Eccentric hypertrophy
What causes concentric hypertrophy
Wall gets thicker due to pressure* overloads like stenosis or HTN
What happens with concentric hypertrophy?
Parallel addition of new myofibrils causes increase in wall thickness
What effect does concentric hypertrophy have on compliance?
Decreased compliance
Which can then cause diastolic problems
What causes eccentric hypertrophy?
Volume overloads
What happens with eccentric hypertrophy?
Ventricle becomes dilated due to the series addition of new sarcomeres
What causes eccentric hypertrophy?
Ventricle becomes dilated due to valve regurgitation, transfusion overload, or increases in diastolic pressure
(Anything that causes a volume overload)
Does the wall get thicker in eccentric hypertrophy?
No, it remains normal. The ventricle just dilates
What neurohormones are released in response to heart failure?
Angiotensin II- vasoconstriction & more blood volume
ADH/Vasopressin-more blood volume
(All of these things may be helpful in the short term to increase venous return and increase stroke volume, but they ultimately lead to peripheral edema and pulmonary congestion)****
What are the main goals of pharamcotherapy for heart failure?
Reduce work load
Reduce edema
Enhance contractility
What effect does Digoxin have to treat heart failure?
Increases contractility
What effect do loop diuretics have to treat heart failure?
Reduce edema
Reduce blood volume
What effect do vasodilators have to treat heart failure?
They reduce preload and afterload
What do ACE inhibitors (Captopril, Enalapril) do?
Inhibit the formation of angiotensin II which decreases preload and afterload and also reduces sodium retention by inhibiting ADH release
Are beta blocker effective for heart failure?
Even though they’re usually used to reduce the contractility of the heart for HTN, they may be appropriate
