Drennan 1 Flashcards
Factors affecting CO
SV*HR
Consequenes of reduced CO
- Tachycardia
- Cardiomegaly
- Arrhythmia
- Fatigue
- SOB
- Pulm edema
- Cyanosis
- Orthopnea
Key thing that happens in CHF
reduction in CO
Decrease in preload leads to
decrease in O2 consumption
Increase in myocardial perfusion
Decrease in afterload leads to
decrease in O2 consumption
Decreased HR will
increase coronary perfusion
Afterload definition
Force distributed in ventricular wall during systole
Limit of starling relationship
Stretching passes a certian point >> actin and myosin are not properly aligned >> no further increase in force can be generated
Optimal length of overlap
2 to 2,2 microns
In Frank Starling curve, increasing contraction will shift the curve ___
upward
(increased SV per a certain EDV)
____ and _____ are inversely related.
What relationship is this?
Stroke volume and Afterload
The force-tension relationship
Failing hearts start to show signs of…
higher sensitivity to afterload for a given stroke volume
Increases in afterload will shift SV down further than normally
Progessive CHF is a disease of:
compensation and decompensation
Compensation = Stable patient, normal activity
Decompensated = acute worsening of CHF
Type of CHF with thin/dilated heart
Systolic failure
(Deficit in contraction)
Thick/stiff walls can’t relax in which type of CHF
Diastolic failure
(Deficit in filling)
afterload, SV, and preload in early heart failure
afterload = high
SV = reduced somewhat
Preload = starts to increase –> drop off normal curve
Compensation for maintaining SV in early HF
Increased Sy
Increased volume (RAAS)
Cardiac remodeling
AT2 effects
- Vasoconstriction
- Stimulates remodeling
- Induces aldosterone
Increased CT in cardiac remodling is due to
cell death and replacement of dead myocytes with fibroblasts
Increased ____ in remodeling with CHF
- Increase in Ca2+ cycling
- Increase in response to Calcium (Ca sensors that will go and mediate Calcium-dependnt genes that play role in hypertrophic response)
CHF drug strategies (and dothey improve mortality)
Manipulate hemodynamics (NO)
Inhibit compensation (YES)
Vasodilators
Diuretics
Angiotensin Inhibitors
Inotropic agents