heart failure

volume and pressure generated in the ventricle at the end of diastole

• 1.  amount of venous return entering the ventricle during diastole 
• 2. blood left in the ventricle after systole [what's left over]

• resistance to ejection of blood from the left ventricle
• pressure in the left must exceed aortic pressure before blood can be pumped out during systole 
• another definition: the amount of resistance your heart has to work against to or overcome to eject blood

is the pumping aspect of the heart. known as S1

the filling aspect of the heart. known as S2

• HTN
• CAD

• change in tension at a given resting fiber length
• ability of the heart muscle to shorten

• volume of blood ejected per beat during systole
• depends on force of contraction which depend on myocardial contractility 
• note that anything that afftect contractiility, preload, and afterloaf load can cause heart failure

the more the myocardial fibers are stretched, the greater the force of contraction

it decreases thus resulting in less CO

"complex clinical syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill with or eject blood."

any interference with normal mechanisms regulating the cardiac output

• preload: too much or too little
• afterload: HTN or CAD = more resistance 
• myocardial contractility: contraction force
• heart rate: HR = CO x SV
• alterations in any of these factors can lead to decrease ventricular function

• CAD
• HTN: due to inc. resistance
• rheumatic heart Dx: due to rheumatoid fever
• congenital heart defect: born with bad valves
• pulmonary HTN: right ventricle affected 
• cadriomyopathy
• hyperthyroidism: can become tachy, inc. O2 demand, heart has to work harder
• valvular Dx
• note that injure to the heart can cause low CO

• anemia: inc. O2 demand
• infection: increase workload on the heart
• thyrotoxicosis: hyperthyroidism 
• hypothyroidsm: assoc with high cholesterol which is assoc with heart Dx which can lead to MI 
• Bacterial endocarditis: from poor oral hygiene and IV pts. 
• pulmonary Dx: COPD, pulmonary HTN 
• Hypervolemia: will cause to much preload

either diastolic or systolic

systolic

• inability to pump blood effectively and perfuse vital organs
• increased workload enlarges left ventricle leading to decreased function
• prevents forward flow of blood
• blood backs up into the left atrium and pulmonary veins 
• can lead to pulmonary edema
• can lead to stress on the right ventricle

• CAD
• Dilated cardiomyopathy
• HTN
• valvular Dx

left ventricle dilated and hypertrophied [becomes enlarged]

• amount of blood ejected per beat
• estimated by doing an echocardiogram
• normal ejection fraction is 60-75%
• decrease is hallmark of ventricular failure

• pulmonary vascular congestion
• dyspnea
• orthopnea [positional SOB]
• cough/frothy sputum
• fatigue [b/c CO dec. causing SOB ]
• decreased urine output [de. CO leads to dec. blood flow to kidneys]
• edema

• cyanosis [fingertips]
• rales [bases of the lungs]
• pleural effusions [fluid in pleura space]
• hypotension/hypertension
• S3 gallop - a third heart sound
• evidence of underlying CAD Or HTN

• a compensatory mechanism 
• triggered by low CO state
• inc. catecholamine release
• inc. HR
• inc. myocardial contractility 
• peripheral vascoconstriction = inc. BP

• a compensatory mechanism 
• dec. CO causes dec. blood flow to kidneys
• kidneys release renin, which converts to antiotensinogen  to angiotensin l 
• angiotensin l, converted by angiotensin convertin enzyme in lung, to angiotensin ll
• adrenal cortex release aldosterone
• retain Na and H2O
• peripheral constriction
• dec. in cerebral perfusion pressure
• posterior pituitary secretes antidiuretic hormone
• water reabsorbtion in renal tubules
• porinflammatory cytokines also released
• endothelin released [vasoconstrictor]

• a compensatory mechanism 
• enlargement of the chambers of the heart
• muscle fibers of the heart stretch 
• inc. contraction initially leads to increased CO
• eventually mechanism fails

• a compensatory mechanism 
• inc. in muscle mas and cardiac wall thickness
• will lead to an increase CO but poor contractility and inc. O2 consumption

• myocyte growth
• up to 6x inc. left ventricle
• ventricular stiffness
• dec. contractility

• heart failure with preserved systolic function or ejection fraction 
• can occur alone or with systolic failure
• more common in women 
• results from dec. compliance of left ventricle

• dyspnea [SOB] on exertion 
• fatigue 
• crackles

• sign/symptoms of heart failure 
• normal ejection function 
• evidence of diastolic dysfunction

• dyspnea
• inc. work of breathing
• pink, frothy sputum

VQ mismatch

• inability of the right ventricle to provide adequate blood flow into the pulmonary circulation 
• can result from left heart failure, COPD, cystic fibrosis 
• pressure rises in the systemic circulation, casuing edema and hepatosplenomegaly [enlarged liver and spleen]

or right sided heart failure, is an enlargement of the right ventricle due to high blood pressure in the ling usually caused by chronic lung disease

• fatigue 
• dependent edema
• distention jugular veins
• liver engorgement
• ascities
• anorexia, GI distress
• cyanosis
• inc. peripheral venous pressure

• CBC - ^ WBC = infection, dec. HNH = anemia
• chemistris 
• LFTs - liver function test 
• TFTs - thyroid function test
• BNP level - signs of heart failure if elevated
• ABG - shows hypoxia
• Echo - meaure ejection fraction, looks @ valve
• EKG - change in 12 lead may indicate LT ventricular hypertrophy 
• CXR
• angiogram - measures CO, EF
• stress test
• genetic testing - cardiomyopathy is genetic

• known as brain natriuretic peptide 
• secreted from the left ventricle in response to stretch 
• normal BNP is less then 100

• falsely elevated in renal dysfunction
• large pulmonary embolism [due to atrial stretch] 
• severe sepsis

the New York Heart Association's Functional classification scale

scale indicated how little or much activity it takes to make patient symptomatic

• class l: no symptoms with activity [go about normal routine]
• class ll: symptoms with ordinary exertion 
• class lll: symptoms with minimal exertion 
• class lV: symptoms at rest
• pts. in class three or four who do not respond to treatment may need to be put on the transplant list

A. at risk for heart failure but without structural heart Dx or symptoms [at risk for heart failure]

B. structural heart Dx but without signs or symptoms of heart failure 

C. structural heart Dx. with prior or current symptoms of HF

D. refractory [no responding to meds] HF requiring specialized interventions

• diverse group of disease that primarily affects myocardium 
• most result of remodeling [changing the shape of the ventricle] cause by MI/neurohormonal reponse to ischemic heart Dx and HTN
• can be secondary to toxic exposure, connective tissue disorders, inflitrative and proliferative disorders, nutritional deficiencies 
• many cases are idopathic

• dilated cardiomyopathy
• hypertrophic cardiomyopathy
• restrictive cardiomyopathy

• most common form
• left ventricle becomes enlarged and dilated. can't pump as efficiently 
• contractility dec. in left ventricle [CO is dec.]
• sinus tachy, atrial and ventricular dysrhythmias 
• systemic or pulmonary thrombeombolism 
• eventually leads to left heart failure

• ischemic heart Dx
• alcoholism 
• pregnancy
• infection
• nutritional deficiencies 
• exposure to toxins

• chamber volume dec. [left ventricle]
• compliance dec., particularly left ventricle 
• heart walls thickens, less space for blood
• ledd blood fills from chamber and is pumped out
• can develop atrial and ventricular dysrhythmias

• HTN
• aortic stenosis 
• inherited defect of muscle growth 
• ex: where you will see young athletes drop dead w/o Sx

• portions of heart wall becomes rigid and lose flexibility 
• compliance dec. 
• eventually leads to right heart failure
• least common

• amyloidosis
• sarcoidosis
• hemochromatosis

• "broken heart syndrome"
• stress weakening of the heart 
• "octopus pot" in Japanese
• can cause lethal heart rhythms 
• lab screening may look normal