Heart Failure, Valve Flashcards
(261 cards)
a pathological state/clinical syndrome where heart is impaired in ability to eject (systolic) or receive blood (diastolic)
cardiac output does not meet perfusion needs of metabolizing tissues and limited exercise capacity
and elevated venous pressures lead to congestion of organs
heart failure
heart failure where cardiac output does not meet perfusion needs of metabolizing tissues and exercise capacity is limited despire normal or higher than normal filling pressure (preload)
Forward or Low output heart failure
heart failure where elevated venous pressures lead to congestion of organs and fluid accumulations (edema, effusion)
Congestion heart failure
How do you determine CO
CO (ml/min) = HR (beat/min) x SV (ml/beat)
What 5 factors influence stroke volume
Preload (+)
Afterload (-)
Contractility (+)
Valve function
Ventricular Synchrony
How do you treat a warm/wet patient (CHF) indicated by jugular distension, dyspnea, cavity effusion, elevated filling pressure with normal cardiac ouput and normal SVR
Diuresis or Vasodilators
How do you treat a cold/dry patient (forward failure) indicated by weak pulse, Low CO, normal filling pressure, low temperature, pain at extremities, arrhythmias, and collapsed
Give Inotropy or Vassopressors
How do you treat a cold/wt patients indicating forward failure and CHF) indicated by cold extremities, collapsed, dyspnea, cavity effusion, Low CO, altered SVR
Hard to treat
-Inotropy
-Vasopressors
-Diuresis (when the perfusion is restored)
What are causes of heart failure due to increased afterload (pressure overload)
1) Aortic or subaortic stenosis
2) Pulmonary valve stenosis
3) Tetralogy of Fallot
4) Pulmonary or systemic hypertension
What are causes of heart failure due to volume overload
1) valve insufficiencies (MR, TR, AI, PI)
2) Shunting lesions (VSD, ASD, PDA)
What can cause impaired contractility leading to heart failure
DCM phenotype
T/F: arrhythmias can lead to heart failure
true- loss of synergy
tachy or bradyarrhythmias
What can cause impaired diastolic filling leading to heart failure
1) HCM phenotype
2) Restrictive cardiomyopathy
3) Pericardial effusion
4) Constrictive pericarditis
*Heart cant relax
what are the causes of heart failure
A) Increased Afterload 1) Aortic or subaortic stenosis
2) Pulmonary valve stenosis
3) Tetralogy of Fallot
4) Pulmonary or systemic hypertension
B) Volume overload
1) valve insufficiencies (MR, TR, AI, PI)
2) Shunting lesions (VSD, ASD, PDA)
C) Impaired contractility
1) DCM phenotype
D) Arrhythmias- loss of synergy; brady or tachyarrhythmias
E) Impaired diastolic filling (heart cant relax)
1) HCM phenotype
2) Restrictive cardiomyopathy
3) Pericardial effusion
4) Constrictive pericarditis
What are compensatory mechanisms in patients with heart failure to buffer the fall in CO and help preserve perfusion
1) Frank-Starling Mechanism
2) Neurohormonal alterations (Sympathetic NS, RAAS, ADH, natiuretic peptides)
3) Development of ventricular hypertrophy and remodeling
Frank-Starling
As there is __________ stretch on myofibers it induces a ________ stroke volume on subsequent contraction
greater; greater
States that with increased stretch on myofibers, it induces a greater stroke volume on subsequent contraction
helps empty enlarged ventricle and preserve forward CO
beneficial compensatory but has limited effect in severe HF cases
Frank-Starling Mechanism
Acute neurohormonal activation during decreases in cardiac output are ________________ while chronic effects are
acute: compensatory and beneficial
chronic: maladaptive and harmful
baroreceptor response
in response to heart failure signal in brain causes SNS activation to increase HR and contractility to increase cardiac output
RAAS activation in heart failure causes
decreased GFR to retain fluid thus increasing preload to increase cardiac output
Increased ventricular wall tension in heart failure causes
myocyte growth leading to hypertrophy and increases cardiac output (with limit)
Where are decreases in cardiac output detected
baroreceptors in the carotid sinus and aortic arch
signals transmitted to medulla
decreased inhibitory input from baroreceptors and mechanoreceptors leading to increase sympathetic tone and decreased parasympathetic activiation causing NE release and stimulation of a and beta receptors
where are the baroreceptors
carotid sinus and aortic arch
What is the SNS response to decreases in cardiac output
1) baroreceptors in the carotid sinus and aortic arch detect decreases in CO
2) signals transmitted to medulla
3) decreased inhibitory input from baroreceptors and mechanoreceptors leading to increase sympathetic tone and decreased parasympathetic activiation
4) NE release and stimulation of a and beta receptors
5) Increased HR, contractility, vasoconstriction (a receptor on systemic veins and arties), RAAS activation