Term
| How does the NYHA classify HF? |
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Definition
Ranges from Class I-IV, which describe progressive worsening of Sx and is made more objective with the MET (metabolic Equivalent Task, where 1 = rate of energy expenditure at rest) units.
I -
II -
III -
IV - |
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Term
| Dyspnea (breathlessness) can be cause of different causes, which are? |
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Definition
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Term
| Dyspnea can also be described as orthopnea or PND, when? |
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Definition
Orthopnea when you lay down and all that blood that was pooling cause of gravity now redistributes around the lungs (NB that pts have adjusted to this by sleeping on >2 pillows)
PND (Paroxysmal nocturnal dyspnea), which comes on after 2-3hrs of sleep when sympathetic stimulation losses to parasympathetics and blood is allowed to pool around the lungs |
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Term
| What is the reason for noturia in CHF? |
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Definition
| During the day the pts have very little renal perfusion but in the night when they lay down, this increases the perfusion |
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Term
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Definition
| Yes, and vise-versa is also true |
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Term
| What are the four main etiologies of LVF? |
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Definition
Inappropriate workload (increased preload as with MR or AR OR increased afterload)
Restricted filling (e.g.. constrictive pericarditis)
Myocardial loss (e.g.. MI)
Decreased myocardial contractility (as in poisoning or infection) |
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Term
| What pathophysiologic changes occur as a result of HF? |
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Definition
Hemodynamic changes
Neurohumoral changes
Cellular changes |
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Term
| Explain the hemodynamic changes? |
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Definition
| Can araise from systolic or diastolic dysfunction or both, NB that either can occur first but eventually lead to the other. |
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Term
| What are the causes of Systolic Dysfunction? |
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Definition
Coronary artery Dz
Valvular heart Dz
Hypertension
Aging
Dilated Cardiomyopathy |
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Term
| What are the two P-V loops for: increased afterload and for myocardial loss? |
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Definition
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Term
| What are the compensatory mechanisms for systolic dysfunction? |
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Definition
I) Increased preload (Frank-Starling relationship) - Note Graph
II) Increased catecholamines (Note graph where ESV is reduced - squeezed out)
III) Cardiac muscle hypertrophy & ventricular volume can increase |
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Term
| Diastolic dysfunction/ HF w/ preserved systolic function/ HF w/ preserved EF is caused by? |
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Definition
I) Decreased relaxation (constrictive pericarditis)
II) Increased stiffness of ventricles (hypertrophic cardiomyopathies) |
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Term
| What does the PV loop looks for Diastolic dysfunction looks like? |
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Definition
| Reduced ventricular EDV but increased EDP. NB that contractility and EF remain normal or even slightly increase as both SV and EDV are decreased - unlike in Sys dys where EF is always low! |
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Term
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Definition
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Term
EF equals?
NB that this is an index of contractility (inotrophic effect) |
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Definition
| SV/ EDV (the fraction of EDV that is ejected in one beat) |
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Term
| What are the Neurohumoral changes in HF? |
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Definition
I) increased Sympathetics
II) RAAS
III) Increased ADH
IV) Release of cytokines & peptides |
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Term
| List and explain some of the cytokines/ peptides in HF? |
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Definition
A) IL-1 accelerated myocyte hypertrophy
B) TNF-alpha causes myocyte hypertrophy and cell death (apoptosis)
C) Endothelin - stimulates vasoconstriciton in pulm vasculature, myocyte growth, myocardial fribrosis
D) ANP & BNP - cause natriuresis & vasodilation |
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Term
| What are the cellular changes in HF? |
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Definition
I) Inefficient handling of intraceullar Ca2+
II) Adrenegic desenitization
III) Myocyte hypertrophy
IV) Cell death (apoptosis)
V) Myocardial fibrosis
This is all collectively known as Ventricular remodeling |
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Term
| Describe mechanism of Dyspnea after pulmonary edema? |
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Definition
| Stimulation of juxtacapillary J receptors. NB that edema of the broncial walls can lead to small airway obstruction and produce wheezing known as cardiac asthma |
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Term
| Describe Dyspnea in terms of reduced vital capacity? |
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Definition
| Replacement of air with blood or interstitial fluid can cause this restricitve physiology and closure of small airways and the pts has to put alot of effort to distend stiff lungs -> fatigue respiratory muscles |
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Term
| The last way to have Dyspnea is via V-Q mismatch, which? |
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Definition
| widens the Alveolar-arterial O2 gradient, hypoxemia & increased dead space (increased pathological shunting) |
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Term
| What are found on physicals of CHF pts? |
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Definition
| Pulsus alternans, bibasilar rales (crackling leaves), base of lung maybe dull to percussion, apical impulse displaced laterally and sustained (when felt during latter part of systole), S3 (heard during rapid filling in early diastole) & S4 (heard during atria kick/ contraction - heard more in pts w/ dia dys or IHD -> decreased compliance) heard, Chest x-ray with bat wings |
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Term
| Systole is btw S1 and S2, whereas? |
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Definition
| Diastole is btw S2 and the next S1. NB that QRS wave is insync with S1 |
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