Heart Failure I - Pathophysiology (complete) Flashcards Preview

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Flashcards in Heart Failure I - Pathophysiology (complete) Deck (22)
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1
Q

What is the prevalence of heart failure in the US?

A

~6,000,000

2
Q

What is the incidence of heart failure in the US?

A

~550K

3
Q

What is the mortality of heart failure in the US?

A

~281K

4
Q

What is the cost of heart failure in the US?

A

> $40 billion

looks like even more prevention efforts are really really needed

5
Q

Why is heart failure so costly in the US? Obviously going for the surface level explanation here. You can have long ass conversations about this

A
  • Highly symptomatic and progressive
  • Causes decreased quality of life, hospitalizations, and death
  • symptomatic pts: half dead in 5 yrs (more deadly than cancer)
  • primarily affects older people (median: 75yrs)
  • Incidence/prevalence increasing b/c of aging pop’n and people surviving initial cardiac disease
6
Q

Define the syndrome of heart failure

A
  • describes lots of signs and symptoms caused by many possible abnormalities of heart function
  • two types: forward failure, backward failure
7
Q

Describe forward heart failure

A
  • Inability of heart to pump blood forward at a sufficient rate to meet metabolic demands of body
  • Overall: POOR forward blood flow
  • Decreased CO
8
Q

Describe backward heart failure

A
  • The ability to pump blood only if cardiac filling pressures are abnormally high
  • Backward buildup of pressure — AKA Congestion => ^ filling pressures
  • A response to low flow
9
Q

What is systole?

A

Ventricular contraction

10
Q

What is diastole?

A

Ventricular relaxation and filling

11
Q

Describe systolic dysfunction

A
  • a problem w/ squeeze => decreased contraction and inotropy

HALLMARKS:
1) Decreased ejection fraction
[e.g. HF w/ reduced EF (HFrEF), LV systolic dysfunction (LVSD)]
2) Ventricular enlargement [e.g. dilated cardiomyopathy (DCM)]

12
Q

What are the causes of systolic dysfunction?

A

1) direct destruction of heart myocytes (e.g. MI, viral myocarditis, alcohol)
2) Overstressed heart muscle (e.g. tachy-mediated HF, Meth abuse, catecholamine mediated)
3) Volume overloaded heart muscle [e.g. mitral regurgitation, high CO (blood shunting, wet beriberi)]

13
Q

Describe diastolic dysfunction

A
  • a problem with filling => decreased lusitropy and relaxation

HALLMARKS:

1) Normal EF [e.g. HF w/ preserved EF (HFpEF), preserved systolic function (PSF)]
2) Ventricular wall thickening [e.g. LV hypertrophy (LVH), hypertrophic cardiomyopathy (HCM)]

14
Q

What are the causes of diastolic dysfunction?

A

1) High afterload/pressure overload (e.g. HTN, aortic stenosis, dialysis)
2) Myocardial thickening/fibrosis (e.g. HCM, 1ary restrictive CM)
3) External compression (e.g. pericardial fibrosis/constrictive pericarditis, pericardial effusion)

15
Q

What are the compensatory responses to decreased CO?

A

1) Neurohormonal activation
2) Frank-Starling increases in preload
3) Ventricular remodeling (hypertrophy & dilation)

16
Q

Describe neurohormonal activation as a compensatory response to decreased CO

A
  • Decreased filling/SV => decreased CO
  • Juxtaglomerular apparatus in kidney senses lower flow => activates RAAS
  • Causes ^ Na retention, vasoconstriction
  • Carotid sinus/aortic baroreceptors sense lower pressure => ANS/adrenergic activation

OVERALL: ^ Na retention + vasoconstriction + ^HR => ^ volume => ^ LV filling

17
Q

Describe Frank-Starling increases in preload as a compensatory response to decreased CO

A
  • ^ LV filling => ^ SV

- SV preserved by increasing end-diastolic filling presure

18
Q

Describe ventricular remodeling as a compensatory response to decreased CO

A
  • Long term cardiac workload & metabolic demand increasing => adverse myocardial remodeling
  • Includes ventricular hypertropy/dilation, myocardial damage/apoptosis, myocardial fibrosis
  • Overtime remodeling=> decreased contractile force and dynamic function, increased diastolic stiffness
19
Q

Describe right sided HF

A
  • normally: RV pumps same amount of blood as LV — does this at lower pressures => RV work is less => RV is a thin walled structure
  • RV stresses => failure to pump blood to lungs
  • Forward RV HF: decreased circulating blood flow
  • Backward RV HF: increased venous pressure
20
Q

What are the causes of right-sided HF?

A

1) Left HF
2) Lung disease/ pulm HTN/ RV pressure overload
3) RV volume overload
4) Damage to RV myocardium

21
Q

Describe left HF as a cause for right-sided HF

A
  • Backward HF from LV dysfunction => stress to right side

- B/c of increasing pulm venous pressure

22
Q

Describe lung disease/ pulm HTN/ RV pressure overload as a cause for right-sided HF

A
  • Cor pulmonale: when 1ary lung disease causes HF

- COPD, 1art pulm HTN, sleep apnea