Heart Failure – Part I:Pathophysiology Flashcards
Heart failure is the inability of the heart to pump blood forward at a sufficient rate to meet the metabolic demands of the body (forward failure), or the ability to do so only if the cardiac filling pressures are abnormally high (___________).”
backward failure
Poor FORWARD blood flow is a key requirement of HF=
LOW FLOW (↓ cardiac output)
BACKWARD buildup of pressure is almost always present as well=
CONGESTION (↑ filling pressures)
Typically a response to low flow
Key Mediators of Blood Flow
Intropy
preload
aftload
cardiac output (=SV*HR)
Ventricular output increases in relation to ______ filling
greater
Heart failure is the inability of the heart to pump blood forward at a sufficient rate to meet the metabolic demands of the body (__________), or the ability to do so only if the cardiac filling pressures are abnormally high (backward failure).”
forward failure
Left ventricular end-diastolic pressure (LVEDP) v. stroke volume
Frank-Starling curves
↑ Preload produces increased _______ (and thus CO)
↑ Inotropy produces increased _____ (and thus CO)
SV
SV
Inotropy =
Determinants are…
=contractility
Catecholaminergic / adrenergic stimulation
Calcium
Major Divisions of HF
Systolic
Diastolic
Left side
Right side
Decreased ejection fraction
“HF with reduced ejection fraction” = HFrEF
“left ventricular systolic dysfunction” = LVSD
Ventricular enlargement
“dilated cardiomyopathy” = DCM
Characteristics of?
Systolic dysfunction
Normal ejection fraction
“HF with preserved ejection fraction” = HFpEF
“preserved systolic function” = PSF
Ventricular wall thickening
“left ventricular hypertrophy” = LVH
Characteristics of?
Diastolic Dysfunction
Impaired filling
↓lusitropy / decrease in relaxation
Diastolic Dysfunction
A problem with squeeze
↓contraction / ↓ inotropy
Systolic dysfunction
Systolic dysfunction Characteristics
Decreased ejection fraction
“HF with reduced ejection fraction” = HFrEF
“left ventricular systolic dysfunction” = LVSD
Ventricular enlargement
“dilated cardiomyopathy” = DCM
Primary causes of systolic HF
Direct destruction of heart muscle cells- MI
Overstressed heart muscle
Volume overloaded heart muscle
Diastolic dysfunction Characteristics
Normal ejection fraction
“HF with preserved ejection fraction” = HFpEF
“preserved systolic function” = PSF
Ventricular wall thickening
“left ventricular hypertrophy” = LVH
Primary causes of diastolic HF
High afterload/pressure overload
Myocardial thickening/fibrosis
External Compression
Under normal circumstances the right ventricle pumps the same amount of blood as the left ventricle, but does it against much _____ pressures
lower
RV work is much less, and thus a normal RV is a ____ structure
thin walled
Stresses to the RV can cause it to fail to adequately pump blood through the lungs, which causes (2)
↓ circulating blood flow (forward RV HF)
↑ venous pressures (backward RV HF)
Primary causes of right-sided HF
Left Heart failure
Lung Disease
RV volume overload
Damage to RV myocardium
muscular tissue of the heart. Other tissues are the endocardium
myocardium
Systolic dysfunction is typically accompanied by ______
diastolic dysfunction (and vice versa)
_______ failure often causes RV failure (most common)
LV
Neurohormal activation
Frank-Starling (increasing preload)
Ventricular hypertrophy and dilation
Compensatory responses of the heart to HF
