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14 Cards in this Set
- Front
- Back
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5 Mechanisms of Heart Failure
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1. Pump Failure
2. Obstruction to flow 3. Regurgitant flow 4. Disorders of Conduction 5. Disruption of the continuity of the circulatory system |
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Diastolic Compliance
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The ability to fill at a given diastolic
pressure |
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Ejection Fraction
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EF=(EDV-ESV)/EDV
- normally 67% - it is the most widely used clinical indicator of Left Ventricular function |
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How do you measure Ejection Fraction?
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- echocardiography
- catheterization - nuclear imaging |
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If preload is increased during diastole, what is the effect on the systolic pressure in the next contraction?
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Systolic pressure is increased (up to a point b/c when the sarcomere length excededs 2.4 um, actin and myosin can no longer interact to cause contraction)
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What is the ideal sarcomere length? Why?
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2-2.4 um
enhances actin-myosin binding |
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What increases inotropy?
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Inotropy = contractility.
- certain drugs such as epinephrine and milrinone - increased heart rate |
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What happens to afterload when pt has sepsis?
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afterload can decrease with sepsis
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What are the Indices of Contractility?
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1. Ventricular function curves
2. Ventricular pressure curves 3. Aortic pressure curves 4. Ejection fraction 5. Pressure-volume loops |
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What are ventricular function curves?
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Relate information about contractility.
- plot CO against Pulmonary Capillary Wedge Pressure - plot stroke work against PCWP |
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What are ventricular pressure curves?
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a chart that plots LV pressure against time (looks like a beel curve)
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What does a ventricular pressure curve for a hypOdynamic heart look like?
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the hypodynamic heart has:
- a lower dP/dt (the slope up to the peak) - higher diastolic pressure - reduced ejection time than a normal heart |
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What does a ventricular pressure curve for a hypERdynamic heart look like?
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the hyperdynamic heart has:
- a lower diastolic pressure - higher dP/dt - brief ejection phase |
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What is the left ventricular end-systolic pressure volume relationship (LV ESPVR) indicative of?
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indicator of inotropy
- steeper the curve = increased contractility - slope would decrease with myocradial ischemia |
