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14 Cards in this Set
- Front
- Back
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Myocardial contractility
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affected by heart rate, drugs, preload, afterload
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Preload
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LV volume at end diastole, determines force of contraction, Frank starling curve increase volume increase contractility.
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Afterload
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resistance to ejection of blood from ventricle during systole. determines the tension of the myocardium. increase resistance decrease stroke volume.
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cubed method
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volume = dimated cubed
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2d/m mode dimensional volumes pitflls
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not major axis, wall motion abnormalities, with a non symmetric lv, over under estimation due to single scan line
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single plane area length volume method
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volume = .85 area squared / length
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ASE recommended volume for ventricles method
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simpsons biplane
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normal lv volumes from simpsons
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LVEDV = men 62-170 women 55-101
LVESV = men 14-76 women 13-60 |
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LV volume pitfalls with simpson
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if difference in length of LV in A2 vs A4 is greater than 20% not accurate
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stroke volume
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SV=EDV-ESV
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EF
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EF% = SV/EDVx100
Normals >55% mildly reduced 40-55% moderately reduced 20-40 severely reduced <20% |
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fractional shortening
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ratios of diameter change during systole and diastole, LVID measures LVIDd - LVIDs/ LVIDd x100. normal 25-45%
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Rv wall thickness
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normal 3-4 mm
hypertrophy >5mm |
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RV sizes
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normal = when LV forms apex, RV smaller, diameter at base <4 cm
enlarged when RV shares apex, equal or larger, diameter at base is >4cm |
