Pathophysiology of Congestive Heart Failure Flashcards
what is the pressure in the right atrium?
0-5 mmHg
what ways can the heart fail?
muscle
valves
electrical
pericardium
outside forces
what are the consequences of the heart failing?
reduced heart efficiency
elevated filling pressures
congestive heart failure
+/- forward heart failure
what is congestive heart failure?
fluid where it should not be as a result of impaired heart function
where can fluid from congestive heart failure be?
pulmonary edema
effusions: pleural, pericardial, abdominal
peripheral edema (horses and people)
how can the heart respond to stress?
increase rate (if it can)
increase vigor of contraction (if it can)
get larger
natriuretic peptides
how can the heart get larger?
wall thickness
chamber dilation
how does a failing heart activate the sympathetic nervous system?
reduced cardiac output leads to hypotension which activates baroreceptors
what is the frank-starling mechanism a relationship between?
stroke volume and ventricular filling pressure
what does increased preload lead to?
increased cardiac output
what is preload?
end diastolic wall stress
what is cellular cardiac remodeling driven by?
types of stress
what does pressure overload lead to?
wall thickening: concentric hypertrophy
what can cause concentric hypertrophy?
outflow obstruction
systemic hypertension
pulmonary hypertension
what can cause eccentric hypertrophy?
leaky valves
left-to-right shunts
what is the body’s response to decreased heart function?
RAAS activation
vasopressin/ADH
chronic sympathetic stimulation
what are the triggers for release of vasopressin/ADH?
hyperosmolarity
angiotensin II, sympathetic, decreased blood pressure
what are the effects of chronic sympathetic stimulation?
vasoconstriction
positive inotrope
RAAS
maintain cardiac output and tissue perfusion
what are the consequences of chronic sympathetic stimulation?
ventricular remodeling
increased afterload
sodium and H2O retention (RAAS)
altered calcium sensitivity
what are the types of heart failure?
left-sided
right-sided
biventricular
how can the heart get larger?
wall thickness
chamber dilation
what does increased wall thickness lead to?
more power
what is increased preload leading to increased cardiac output mediated by?
stretch of sarcomeres and calcium
what is the failing heart dependent on?
afterload
how long does cellular cardiac remodeling take?
weeks to months
what triggers vasopressin/ADH release?
hyperosmolarity
angiotensin II
sympathetics
decreased blood pressure
what are the effects o vasopressin/ADH with the V1a receptor?
vasoconstriction
what are the effects of vasopressin/ADH with thee V2 receptor?
water retention
what is chronic sympathetic stimulation triggered by?
baroreceptor dysfunction
altered chemosensitivity
decreased clearance of norepinephrine
how do we go about treating congestive heart failure?
remove congestion
support heart function
reduce adaptive responses
in what can forward failure occur?
dilated cardiomyopathy
