6- Pathophysiology of Congestive Heart Failure Flashcards
define heart failure
inability of heart to meet metabolic demands of body
classic 3 symptoms of heart failure
dyspnea, increased fatigue, and fluid accumulation
structural abnormality of cardiac tissue
cardiomyopathy
New York Heart association CHF classification
1-4 with 4 worst = symptoms at rest
HF with preserved ejection fraction
compensated heart failure
heart failure with low ejection fraction (40%) =
cardiac congestion
cardiac congestion =
more volume staying in the ventricular chamber with each heart beat
causes of cor pulmonale (right HF)
- vascular dysfunction
- hypoxia
- parenchymal disease within lungs
- left heart failure
how does left heart failure cause right heart failure
severe left-sided congestion results in right sided dysfunction as pulmonary edema and pulmonary venous pressure alter the afterload of the right heart
compensatory mechanism to offset reduction in stroke volume
ventricular hypertrophy
maladaptive consequences of ventricular hypertrophy
- regurgitation
- calcium contractiity imbalance
- increased metabolic demand of myocardium
cochanges in calcium cycling imparis…
contractiona nd relaxation of myocytes
can contribute to exercise intolerance because the heart is functionally unable to match increased demand
the _________ nervous system is activated in HF. the ________ is defective
symp activated
para defective
- this increases peripheral vascular resistance
the _______- reflex is blunted while the _________ is augmented
baroreflec is blunted (an inhibitory reflex) and teh chemoreflex (excitatory) is augmented
why is treament with beta adrenergic blockers beneficial in HF
because the receptors are desensitized leading to a decreased response to adrenergic stimualtion
compensatory processes try to mitigate the reducation in SV by…
increasing preload (by increasing venous return) and also increasing contractility of heat
hwo does vasodilator treatment help with HF?
redues afterload, so the heart can eject a larger SV
does diastolic dysfunction happen right away in HF?
no - occurs with time as hypertrophy and other remodeling compromise ventricular relaxation
true or false: disatolic dysfunctioin reduces stroke volume
FALSE
not at first at least, it generates higher diatolic pressures within the ventricles which can lead to impaired filling
central venous pressure is _________– in HF
elevated
target of diuretic HF treatment
reduce volume
target of ACEi, ARB
reduce remodeling, afterload, myocardial metabolic demand
target of beta blocker
counter sympathetic effects
target of statins
dyslipidemia and pleiotropic effects
(equation) ejection fraction =
SV/ EDV
what part of RAAS is associated with vasoconstriction, hypertrophy, proliferation and increases in hormones, salts?
AT1
inflammation, growth, vasoconstriction, thrombosis
what part of RAAS is associated with aldosterone and heart structue and kidney changes?
ATII
fibrosis, electrolyte imbalance, heart faiulre
3 compensations for systolic dysfunction
- increase preload
- increase contractility (symp)
- ventricular hypertrophy, elasticity
- decreased tissue compliance
- increased passive stiffness
- delayed myocyte relaxation
- depressed ATP levels
- diastolic calcium leak
diastolic dysfunction
HF
ventricular hormone released in response to strecth
b type natriutetic peptide
can differentiate from pulmonary failure
