Ch. 20 Heart Failure and Circulatory Shock Flashcards
Heart Failure & Circulatory Shock
- go hand in hand
- either both are in healthy states or both are in unhealthy states
- a structural disorder (defect in form) leads to a functional disorder and vise versa
What is a common initial functional disorder? and the resulting structural disorder?
HTN, the result is thickening of the heart muscle
pumping against abnormally high pressure puts excess strain on what chamber of the heart?
left ventricle
What is heart failure? what does it result in?
functional and structural disorder that results in….
- low cardiac output
- systemic or pulmonary congestion
What are some common causes of heart failure?
- CAD
- HTN
- Dilated Cardiomyopathy
- Valvular heart disease
What does heart failure mean?
- decreased pumping ability of the heart and compromised compensatory mechanisms needed to maintain cardiac output
- occurs because the cardiac output is low and the body becomes congested with fluid due to an inability of heart output to properly match venous return
Cardiac Output=
stroke volume + heart rate
What are some cardiac performance indicators?
- preload and afterload
- cardiac output and cardiac reserve
- myocardial contractility
- ejection fraction
preload
- volume(loading capacity) of the ventricles at the end of diastole (filling)
- volume coming into the heart
- primarily increased venous back pressure
afterload
- force of contraction required to eject (circulate) blood
- supplying adequate arterial perfusion
Central Venous Pressure (CVP)
- indicator of preload
- when volume is decreased, CVP will be low
Pulmonary Vascular Resistance
- resistance to the lungs
- back up before the heart, increased afterload
Cardiac Output
- the amount of blood pumped out of the heart each time
- stroke volume + HR =cardiac output
Cardiac Reserve
- the ability of the heart to increase it’s output during increased activity
- people with heart failure lose this ability
What is the pathophysiology behind heart failure?
interaction between decreased ability to pump and decreased compensatory mechanism to maintain cardiac output
Myocardial Contractility
- ability to squeeze
- contractile performance of the heart
- inotrope: force of contraction
Inotrope is synonymous with what word?
contractility
Stroke volume
volume pumped out each time
What is the normal cardiac output?
4-8 liters per minute
What are some example of stimulations of the sympathetic nervous system and how does it affect the heart?
- anger, pain, fear, caffeine
- increase HR, increase contractility, increase speed of induction
What are some example of stimulations of the parasympathetic nervous system and how does it affect the heart?
- vomiting, medications, full bladder, Val Salva maneuver (what you do during a BM)
- decreased HR, Decreased force
Ejection Fraction =
amount of blood pumped out of the ventricles
____________________________________
the total amount of blood in ventricles
how is the ejection fraction monitored and what is a normal value?
- cardiac imaging
- 55% - 75%
What are the types of Heart Failure?
- Systolic v Diastolic
- Right v Left Ventricular
- High-output v Low-output
Systolic Dysfunction
- impaired contraction (will have backup in the atriums, the preload areas)
- ejection fraction <40%
- causes backup in atria and the pulmonary system (congestion)
- increases preload
Diastolic Dysfunction
-Abnormality in the ventricular relaxation and filling
(ventricle can’t expand therefore can’t fill up during diastole)
-increased intra-ventricular pressure
-pulmonary back up and congestion
-influenced by heart rate
what causes systolic dysfunction?
- ischemic heart disease (plaques, atherosclerosis)
- cardiomyopathy (floppy heart)
- HTN
- valvular problems
what causes diastolic dysfunction?
- pericardial effusion
- constrictive pericarditis
Which type of heart failure is often referred to as the “ failure of pump action”?
systolic dysfunction
Right Ventricular Heart Failure
- pulmonary congestion is minimal maybe even clear
- patients will have weight gain due to peripheral edema and suffer from bilateral pitting peripheral edema
- most common cause is left sided heart failure
- systemic and hepatic accumulation
Fluid build up in the body and hepatic system is related to what type of heart failure?
right sided
Left Ventricular Heart Failure
- diminished cardiac output
- progressive accumulation of blood within the pulmonary circulation (crackles)
- most common cause of left sided heart failure is Acute MI
- # 2 is HTN
- could be caused by valvular problems
In which type of heart failure will you see pulmonary edema and hear crackles when auscultating the lungs?
left sided heart failure
What is it called when right sided failure is caused by only pulmonary issues and not left sided failure?
Cor Pulmonale
S/S of Right Sided Heart Failure
- fatigue
- Increase peripheral venous pressure (aka CVP)
- ascites (big belly)
- enlarged liver and spleen
- distended jugular veins (sign of increased CVP, doesn’t always mean it is Right sided heart failure, could be other cause)
- anorexia and complains of GI distress
- weight gain (fluid in the 3rd space)
- dependent edema (whatever part is down)
S/S of Left Sided Heart Failure
- paroxysmal nocturnal dyspnea
- pulmonary congestion: cough, crackles, wheezes, blood-tinged sputum
- tachypnea
- restlessness
- confusion
- orthopnea
- tachycardia
- exertional dyspnea (no reserve)
- fatigue
- cyanosis
Congestive Heart Failure
- CHF or CCF (congestive cardiac failure)
- heart is unable to provide necessary pumping to provide body with adequate supple of blood
Chronic: progressive slowly after MI, return to ER a lot, swollen ankles, tired
Acute: suddenly after MI, pulmonary embolism or some type of arrhythmia
How do you diagnose congestive heart failure?
- physical exam
- confirmed with echocardiogram
- blood tests to determine cause
Treatment of Acute Decompensating CHF?
- managed with urgent therapy (Meds,O2, hospitalization)
Treatment of Chronic CHF in stable situation?
- stop smoking
- light exercise
- dietary changes(less animal fat, more vegetable fat, less calories)
- pharmacological modalities(diuretics, inotropes, antihypertension)
- pacemaker
- if heart is shot then a heart transplant is needed
What is an LVAD?
- left ventricle assist device
- usually patient is on before a transplant
High-Output
- uncommon type
- excessive need for cardiac output
- output is normal but not enough to meet demand
-compensatory for anemia
Low-Output
- caused by disorders that impair the pumping ability of the heart such as heart disease and cardiomyopathy
- clinical evidence of systemic vasoconstriction (body tries to keep pressure at cold)
ex: cold, pale, cyanosis of extremities
Frank-Starling Mechanism
- increased volume of blood stretches the ventricular wall, causing cardiac muscle to contract more forcefully
- stroke volume increases in response to increase blood volume filling the heart
- will see state as a “curve”
other compensatory mechanisms
a lot of mechanisms run 24/7 in the body
-body is constantly adjusting to maintain cardiac output
What are some things that affect the Frank-Starling Mechanism?
-CAD, HTN, DCM, valvular heart disease
all of these things…
- increase workload of heart
- decrease ability to compensate
- decrease contractility
- ultimately overloading ventricles
Why is the Frank-Starling Mechanism important?
allows cardiac output to be synchronized with the venous return without depending on any external regulation controls. it is right there in the heart
Acute Pulmonary Edema
- AKA: Flash Pulmonary Edema
- (left sided - lung)
- capillary fluid moves into alveoli
- shortness of breath and cyanosis
- tachycardia, cyanosis, skin moist and cool
- confusion, stupor, air hunger
