Patho: Cardiac -HF & Cardiomyopathies

What cause HF?

inadequate pump function of the heart

What does HF lead to?

congestion from fluid in the lungs and peripheral tissue

Physical exam findings of LV failure

Inc HR and RR, pales, sweaty, HF, pulses alternans, rales, 3rd and 4th heart sounds, displaced apical impulse

Etiology of LV failure

volume overload, pressure overload, restricted filling, myocyte loss, decreased myocyte contractility

HFrEF is what kind of problem

systolic: pump

HFpEF is what kind of problem

diastolic: filling

What kind of changes will appear in LV failure?

hemodynamic,neuro-hormonal, cellular

HFrEF results in the the contractility of the P-V loop to shift down and to the left. What does this cause?

reduces SV → decreases CO

What drug is used to stop/slow the release of catecholamines?

Beta Blockers

How does the heart compensate for HFrEF in an attempt to maintain CO?

• Inc preload → inc contraction → inc EDV

• Inc catecholamine release → inc HR → inc CO

• Inc hypertrophy and ventricular volume → shifts compliance to the right

HFpEF causes the compliance curve to shift up and to the left. What does this cause?

increase in LV end-diastolic pressure → reduced filling

HFpEF can be present in any disease that causes:

• decreased relaxation

• decreased elastic recoil

• increased ventricle stiffness

Severe ischemia leads to …

MI

Most patients have what kind of HF?

combination of HFrEF and HFpEF

What type of neuro-hormonal changes are seen in LV failure?

SNS activated, RAAS activated, vasopressin release, cytokine release

What kind of cellular changes are seen in LV failure?

inefficient intracellular Ca handling, adrenergic desensitization, myocyte hypertrophy, re-expression of fetal phenotype proteins, cell death, fibrosis

Over time, near-hormonal changes meant to maintain CO in heart failure lead to ___ of cardiac function.

progressive deterioration

Which hormone causes efferent glomerular arteriolar vasoconstriction to help maintain GFR despite a reduced CO?

Angio II

Which neurotransmitter may accelerate myocyte hypertrophy?

Interleukins (ILs)

Which neurotransmitter has an important role in the cycle of myocyte hypertrophy and cell death?

tumor necrosis factor (TNF)

Which neurotransmitter is released from endothelial cells and linked to pulmonary hypertension?

endothelin

In HF delivery and reuptake of Ca2+ are ___

slowed

What receptors are important for the induction of myocardial hypertrophy?

a1-adrenergic

Due to chronic sympathetic activation in HF, there is significant ____ of the B-adrenergic receptors.

desensitization

Constant turnover of the contractile proteins of sarcomeres lead to myocyte hypertrophy and re-expression of what?

fetal and neonatal forms of myosin and troponin

What does hypertrophy of the heart due to hemodynamic stress lead to?

LV remodeling

An increase in fibrous tissue in interstitial space of the heart ____ contractility

decreases

HF is associated with gradual ___ of the ventricle

dilation

Clinical manifestations of LV failure

SOB, orthopnea, PND, fatigue, confusion, nocturia, chest pain

Clinical manifestations of RV failure

SOB, pedal edema, abdominal pain, anasarca, ascites, hepatojugular reflux

What is the most common cause of RV failure?

LV failure

physical exam findings of RV failure

third heart sound at sternal border, sustained systolic heave, elevated JVP, LV failure signs

Etiology of RV failure

LV failure, congenital/idiopath Pul HTN → inc afterload, pulmonary disease, RV ischemia

A MI in the inferior wall will lead to ischemia and damage to what area of the heart?

RV

How does isolated RV failure contribute to LV failure?

inc in RV pressure → IVS bow into LV → reduced filling

What causes JVP? (besides HF)

pericardial tamponade, constrictive pericarditis, massive PE

If a pt has LV failure, their SOB is due to

pulmonary edema

If a pt has RV failure, their SOB is due to

pulmonary disease

A reduction of right sided CO results in what?

acidosis, hypoxia, air hunger

If RV failure is due to a defect on the left side (mitral stenosis), onset of RV failure decreases the load on LV and thereby ___

lessens symptoms of pulmonary edema

What are the 3 ways the heart remodels itself in cardiomyopathies?

dilate, hypertrophy, restrictive

What physiological cause leads to myocardial hypertrophy?

heart pumping more efficiently in highly trained athletes

What pathological causes lead to myocardial hypertrophy?

hemodynamic overload, MI, valvular insufficiency

Which form of cardiac remodeling lead to thin heart layers?

cardiac dilation

Which form of cardiac remodeling leads to small chambers and thick walls?

pathological

Which form of cardiac remodeling will return to normal when no longer necessary?

physiological

What is the most common type of cardiomyopathy?

dilated cardiomyopathy

What form of cardiomyopathy is the cause behind many cases of cardiac transplants?

Idiopathic DCM (primary)

What form of cardiomyopathy is a result from injury to the cardiac myocytes?

Secondary DCM

characteristics of DCM

biventricular, dilation, impaired contraction, eventual CHF

Non heart disease causes of DCM

alcohol, genetics, viral infection

DCM causes the contractile elements to not align which decreases the hearts ability to what?

effectively contract

Why do pts with DCM often need a defibrillator?

pts are susceptible to sudden death to to atrial or ventricular arrhythmias

What form of CM is characterized by a thickened, hyperkinetic ventricular muscle mass?

Hypertrophic obstructive CM (HOCM)

In HOCM what area is most affected by hypertrophy?

septum

What cardiomyopathy is the #1 cause of sudden death in young athletes?

HOCM

What causes HOCM?

genetic abnormalities and abnormal sarcomere proteins

What is unique about the cardiac cells in HOCM?

cells are disorganized: appear as whorls

characteristics of HOCM

inappropriate LV response, hyper dynamic LV contractility, stiff non-compliant LV

How does HOCM cause sudden death?

strenuous activity proves outflow obstruction: septum blocks aortic valve

What is the rarest form of CM and characterized by a stiff, fibrotic ventricle?

restrictive

restrictive CM is due to a ___ issue

filling

What % of pts with RCM survive past 10 years?

10%

RCM usually presents secondary to what diseases?

infiltrative: sarcoidosis, amyloidosis, hemochromatosis