Week 2 Heart Failure Flashcards Preview

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Flashcards in Week 2 Heart Failure Deck (21):
1

Define heart failure

A clinical syndrome of progressive weakening of the hearts pumping function. Causes systemic, organ, and cellular changes. Cause of death is eventually a progressive loss of myocardial cells and arrhythmia.

2

Heart failure demographics

Total prevalence: 0.4-2.0% In people over 65: 6-10% Mean age is >70 years, and is the most common ailment of individuals over 65. Prevalence is increasing, likely due to environmental/lifestyle factors. Bad prognosis, with a 5 year survival rate of ~50%

3

Classifications or types of heart failure

Acute/Chronic

Forward/Backward

Systolic/Diastolic

Left Sided/Right Sided

Congestive

 

 Forward: LV cannot supply the body with sufficient blood, inadequate systemic perfusion. 

 Backward: congestion of the venous system, right or left atrium, or pulmonary system, because ventricle ejects less blood than it recieves.

 

Systolic: Due to reduced systolic ejection

Diastolic: Due to reduced diastolic filling 

4

Equation to calculate the Ejection Fraction

What is the normal EF?

What EF ranges indicate certain disorders?

EF = Stroke Volume / End Diastolic Volume

EF= SV/EDV

Normal is 55-75%

 

EF is defined as Systolic Dysfunction, also called HF-REFHF with Reduced EF

EF between 35-50% is Diastolic Dysfuction, also called HF-PEF: HF with Preserved EF

5

Symptoms of Left Heart, Backward Failure?

Pulmonary Rales  - due to liquid in the alveoli

Dyspnea - difficulty breathing

Orthopnea - easier to breath when sitting up or standing than when laying

Paroxysmal Noctournal Dyspnea - because they are laying down, as they slip down into a laying position asleep and fluid accumulates in lung, and then they wake up suddenly with severe dyspnea. Used to be caused Cardiac asthma

 

 

6

Symptoms of Left Heart, Forward Failure

Weakness, Fatigue, because of insufficient systemic perfusion

Nocturia, due to increased return from the body when laying down at night. 

7

Symptoms of Right Heart, Backward Failure

Edema, Hydrothorax 

Congestive Hepatomegaly

Distended neck veins

Cyanosis

S3 gallop, the third heart sounds

8

Diagnosis of heart failure

Anamnesis and current complaints

ECG, no specific sign, but anyone with heart failure will have some kind  of ECG abnormality

Chest X-ray

Echocardiography to measure Ejection Fraction 

 

Biomarkers:

BNP - Brain netriuretic peptide

NT-proBNP - N-terminal pro BNP

ST2 - indicates myocardial stretch

hs-cTnT - high sensitivity cardiac troponin T, 

    -hs-cTnT is mildly elevated in Heart Failure. Highly elevated in Myocardial Infarct

9

Underlying causes of heart failure

Ischemic heart disease - Infarcts or just a more mild ischemic heart

Hypertension

Diabetes Mellitus

Obestity --> Metabolic syndrome --> Diabetes + hypertension

Cardiomyopathy  -> caused by alcoholism or genetic factors

Valve disease

10

What is an S3 Gallop?

An audible 3rd heart sounds

Is normal in young people or in athletes

Abnormal in people suspected of heart failure

Produced by the rapid halting of blood flow into the ventricles from the atria.

 

11

Precipitating causes

Increased workload, increased metabolic need

   -activity, fever, infection, hyperthyroidism

 

Volume overload

  - Renal failure, high sodium intake, hypervolemia

 

Pressure overload (although these are considered Circulatory Failure not exactly Heart Failure)

   - High blood pressure

   - Pulmonary embolism

 

Weakened heart 

   - Cardiac Ischemia

   - Decreased pump efficiency, due to Arrythmias

   - Drug effects

   - Infection or inflammation of the heart Endocarditis, Myocarditis

 

12

Determinants of Cardiac Output

Heart rate x Stroke Volume = CO

 

Things that effect stroke volume: Inotropy, Lusitropy, Preload, Afterload

Inotropy the force of contraction

Lusitropy the extent of relaxation

13

Draw out the Pressure-Volume loop of the heart

What portion of the graph is equal to the work of the heart?

The total area under the curve = the work of the heart

14

Does Ischemia cause systolic or diastolic dysfunctions?

It causes both, decreasing contractility and also decreasing flexibility

15

What are some of the Calcium and ATP disturbances seen in heart failure patients?

Ryanodine receptor leaks Ca++ from SR during diastole, Causes weakened contractions. 

SERCA transporter is less effecient, less Ca++ in SR, more Ca++ in cytoplasm, both weakening contraction, and impairing relaxation

 

Less ATP and more ADP in cardiomyocytes. Due to low phosphocreatine levels.

In HF there is a shift from mostly fatty acid oxidation towards more glucose metabolism

16

Describe the hemodynamic defense reaction seen in HF.

Efforts of the vascular system to maintain CO and blood pressure during heart failure. 

 

Salt and water retention

   -increases preload, boosts CO, also causes edema and pulmonary edema

Vasoconstriction

   -increases afterload, boosts BP, also increases workload and decreases CO

Cardiac stimulation

   -Increases contractility, relaxation, and heart rate, also increases workload and may prompt arrhythmias and sudden death

 

17

Describe the Inflammatory Reaction of Heart Failure

Low grade inflammation that occurs during HF, unclear exactly why

 

Benefits of it:

Produces protective proteins like Heat Shock proteins, 

not exactly clear what the benefit is

 

Detriments: 

Cardiac Cachexia (wasting/weight loss due to HF)

Apoptosis

Necrosis

 

18

What are 3 major systemic responses to Heart  Failure

Hemodynamic Defense Reaction

Inflammatory Reaction

Hypertrophic Response

19

Describe the Hypertophic response of HF

Gene expression changes, causing both adaptive hypertrophy and maladaptive hypertrophy

 

Genes changes: TGF-beta and IGF-1 increased, FGF decrease

Adaptive: Increased Sarcomere Number and Cardiac Output

Maladaptive: Tissue Remodeling, Increased Energy Demand, Increased Apoptosis

20

How is HF treated?

1) Prevention is most important

2) Determine the underlying cause 

3) Try to manage and remove precipitating causes

4) Treat Symptoms

   -Diuretics to manage the congestion. Alleviates backward failure but exacerbates forward failure (still preferable tho)

5) Support heart and circulation

 

Implantable Cardioverter-defibrillator --> to treat malignant arryhthmias. Can act as a pacemaker for bradycardia, but can also deliver a defibrillator shock in the case of malignant arrythmia to terminate it and reset rate. 

21

Drug treatments for Heart Failure

Beta agonists: Can save life in immediate danger, but chronic use actually shortens life span.

Digitoxin: "whip" increases heart strength

Vasodilators to decrease the load: ACE inhibitors

Beta-Blockers - definitely indicated for heart failure

ACE inhibitors and Beta blockers are good well established therapy to extend lifespan. 

Heart Transplant

LVAD Left ventricular assist devices implanted