Pathophysiology of Heart Failure

Question 1

name the three major types of cardiomyopathy

Answer 1

dilated
hypertrophic
infiltrative/restrictive

Question 2

4 common myocardial insult causes of dilated cardiomyopathy

Answer 2

late stage viral myocarditis
ethanol toxicity
toxic injury from cobalt or chemotherapeutics
post pregnancy

Question 3

what causes 20-50% of dilated heart failure?

Answer 3

genetic linkages…mainly autosomal dominant

Question 4

what type of proteins do genetic abnormalities causes dilated heart failure usually make?

Answer 4

cytoskeletal proteins connecting to contraction bands

Question 5

in dilated cardiomyopathy, how is the heart sized?

Answer 5

still really big…like 800 grams

Question 6

what type of hypertrophy occurs in dilated cardiomyopathy? in series or parallel?

Answer 6

eccentric hypertrophy…in series

Question 7

what type of hypertrophy in pathological hypertrophy cardiomyopathy? in series or parallel?

Answer 7

concentric in parallel

Question 8

what occurs between the myofibrils in dilated cardiomyopathy?

Answer 8

a lot of fibrosis

Question 9

what viruses often cause myocarditis that leads to DCM? and what will you see histologically?

Answer 9

parvovirus b19
echovirus
HIV
Coxackievirus B

infiltration of lymphocytes in the myocardium

Question 10

name a common drug that can lead to DCM?

Answer 10

doxorubicin

Question 11

what is seen on EKG for DCM?

Answer 11

LVH signs…high R and S waves in V leads

T wave inversions and ST depressions

Question 12

what two things must you do to diagnose DCM?

Answer 12

echocardiogram and see ejection fraction less than 40%

no significant CAD via stress test or cardiac cath

Question 13

name three rare reversible causes of DCM?

Answer 13

tachycardia, alcohol use, and hyperthyroidism

Question 14

how do we rule out hyperthyroidism as a cause of DCM?

Answer 14

check TSH levels

Question 15

due to the poor blood flow in the heart, what is possible in DCM?

Answer 15

thrombosis…prophylactic treatment not indicated though

Question 16

what genes products are usually affected in hypertrophic cardiomyopathy?

Answer 16

beta myosin heavy chains about 1/3 of cases

then tropomyosin and troponins..

pretty much any type of sarcomeric contractile protein

Question 17

in hypertrophic cardiomyopathy, where is the hypertrophy most pronounced?

Answer 17

the LV and the IVS

Question 18

due to LV hypertrophy, what else can enlarge in hypertrophic cardiomyopathy?

Answer 18

increased pressure in LA causes it to hypetrophy secondary to LV hypertrophy

Question 19

explain the issue that arises with flow in hypertrophic cardiomyopathy..what is the name of this problem?

Answer 19

due to the narrowing of the aorta outflow tract, the velocity of flow causes a vacuum that sucks the anterior leaflet of the mitral valve over to the septal wall and it leads to mitral regurgitation…

this is called systolic anterior motion of the mitral valve (SAM)

Question 20

what induces the SAM effect?

Answer 20

anything that leads to less blood volume

Question 21

what are the changes in contractility and preload in HCM?

Answer 21

contractility stays the same, but preload drops because of the stiffness of the LV

Question 22

what does the diastolic dysfunction in HCM lead to in the lungs and how?

Answer 22

high pressure in LV backs up into LA and into pulmonary tract causing pulmonary edema

Question 23

what are the four most common symptoms of HCM?

Answer 23

dyspnea
angina
palpitations
sudden cardiac death

Question 24

why angina in HCM?

Answer 24

so much more tissue, so little vasculature so get some ischemic conditions

Question 25

how large must wall be to be HCM? and what other things to do for diagnosis of HCM?

Answer 25

more than 15 mm genetic testing can be done exclude other things like hypertension cause

Question 26

what is the cause of SuddenCardiacDeath from HCM?

Answer 26

an arrhythmia that is caused by the myofibrillar disarray and fibrosis

Question 27

what should we give to those at risk of SCD?

Answer 27

ICD

Question 28

what four things give high risk for SCD from HCM?

Answer 28

wall thickness over 30 mm history of syncope family history of SCD previous V tach

Question 29

name three auscultation findings with HCM?

Answer 29

S4 from atrial contraction against stiff ventricle holosystolic murmur of mitral regurg from SAM crescendo-decrescendo murmur from turbulent out flow in aorta

Question 30

will you hear an S4 if someone is in a fib?

Answer 30

oh NO!

Question 31

if you hear a crescendo decrescendo systolic murmur...what two things are on the differential?

Answer 31

aortic stenosis and HCM

Question 32

what two maneuvers can you do to help determine if aortic stenosis versus HCM and why do these work with the murmur?

Answer 32

valsalva-decreased preload to the LV which means the HCM murmur will be louder, but aortic stenosis will not change squat to stand- also decreases the preload and has same effect on the two murmurs

Question 33

describe the two surgical procedures for HCM

Answer 33

myectomy...cut out some of the increased size septum alcohol septal ablation..inject alcohol to kill tissue...problem is this can lead to blocks since automaticity cells close bye

Question 34

name five infiltrative cariomyopathy causes

Answer 34

``` cardiac amyloidosis endocardial fibroelastosis hemochromatosis sarcoidosis radiation injury ```

Question 35

where does amyloid accumulate in cardiac amyloidosis

Answer 35

interstitially...leads to myocyte atrophy

Question 36

what is the staining for amyloid?

Answer 36

congo red stain

Question 37

what color will myocardium be grossly with amyloidosis?

Answer 37

gray/pink

Question 38

what causes hemochromatosis heart failure?

Answer 38

excessive deposits of iron in the heart lead to myocyte hemosiderin and interstitial fibrosis

Question 39

what color is gross myocardium in hemochromatosis?

Answer 39

a darker brown muscle color

Question 40

what stain can you do for hemochromatosis? what color is the iron?

Answer 40

an iron stain...iron appears blue

Question 41

sarcoidosis HF is caused by formation of what in the myocardium?

Answer 41

granulomas

Question 42

what is endocardial fibroelastosis and what age does it affect?

Answer 42

less than 2 years old... have abundance of fibroelastic tissue in the endocardium of usually the LV...can cause HF

Question 43

grossly, where do you see endocardial fibroelastosis and what color is it?

Answer 43

on the interior surface of the heart...will be whitish color from the fibrosis

Question 44

what is unique grossly about amyloidosis compared to other forms of HF?

Answer 44

the RV is involved more...almost even with LV changes...whereas in others it is mainly the LV

Question 45

EKG findings for amyloidosis

Answer 45

extremely low voltage throughout due to amount of proteins that inhibit electrical system to reach the leads

Question 46

what is the treatment for cardiac amyloidosis?

Answer 46

really not much...maybe a transplant

Question 47

how do we image cardiac sarcoidosis?

Answer 47

biopsy or nuclear/MRI imaging

Question 48

treatment for cardiac sarcoidosis?

Answer 48

glucocorticoids and standard heart failure meds pacemaker and transplant if bad enough

Question 49

define arrhythmogenic RV cardiomyopathy

Answer 49

RV hypertrophy due to fatty infiltration in the RV

Question 50

what does arrhythmogenic RV cardiomyopathy often lead to?

Answer 50

ventricular arrhythmias, SCD and right heart failure

Question 51

what usuallt causes arrhythmogenic RV cardiomyopathy

Answer 51

genetic mutation for desmosome proteins

Question 52

what can you give treatment wise for arrhythmogenic RV cardiomyopathy

Answer 52

ICD for arrhythmias and tell them not to play sports