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37 Cards in this Set
- Front
- Back
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Comparison of Normal ventricle sizes
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Left ventricle 3x greater than right ventricle b/c has to overcome SVR which is greater than PVR
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Concentric hypertrophy
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-LV chamber size is normal
-Hypertrophic myocardium from pressure overload -Causes: chronic HTN, aortic stenosis -Increased amount of wall stress = increased contractility but also increased O2 demand, @ a point hypertrophy will lead to CHF -Associated with Law of LaPlace |
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Eccentric hypertrophy
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-Large LV chamber from volume overload
-Causes: ischemic heart dx, MI -Increased chamber size in r/t increased end-diastolic volume, eventually increased stretch/volume will lead to CHF -Systolic dysfunction, yet during diastole maintain end-diastolic wall stress = increased O2 demand |
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Mitral Stenosis
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-Normal orifice: 4-6cm2
-Begin of S/S: <2cm2 -Severe stenosis: <1cm2 -Decreased Blood Flow from LA to LV -If PCWP >25mmHg = increased PVR = Pulm HTN/edema -Trt: anticoagulatns, Na+ restriction, diuretics, valve replacement |
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Monitoring for Mitral Stenosis:
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PCWP overestimates LVEDP
Prominent A wave, decreased y-descent |
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Anesthesia Goals for Mitral Stenosis:
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Rate: slow
Rhythm: NSR Preload: maintain Afterload: maintain Contractility: maintain -Caution in SAB, epidural preferred, avoid ketamine/pancuronium, treat tachycardia, trt A-Fib with digoxin/diltiazem but NOT VERAPAMIL b/c greater vasodilating effects, trt symptomatic SVT, drug of choice for hypotension: phenylephrine |
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Mitral Stenosis Curve:
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Leftward shift, decreased amplitude
-Decreased LVEDV + Decreased LVESV = Decreased SV (in severe dx) |
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Mitral Regurgitation Pathophysiology:
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-Acute Causes: papillary muscle dysfuntion, infective endocarditis, trauma
-Chronic Causes: rheumatic fever, valve degeneration -Result: backflow of blood from LV to LA during systole, can decrease CO -Volume Overloaded chamber = dilation = eccentric hypertrophy |
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Mitral Regurgitation Symptoms:
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-Moderate Symptoms: 30-60% regurgitant fraction
-Severe Symptoms: >60% |
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Treatment Mitral Regurgitation:
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Inotropes (digoxin, amiodarone), decreased SVR, diuretics, ACE inhibitors, valve replacement
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Monitoring Mitral Regurgitation:
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-Large V wave, rapid y descent
-PCWP underestimates LVEDP |
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Anesthesia Goals for Mitral Regurgiation:
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Rate: avoid bradycardia, ideal is 80-100bpm
Rhythm: NSR Preload: maintain Afterload: maintain Contractility: maintain -SAB/epidural good, sensitive to myodcardial depressants, opioid/pavulon if severe |
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Acute Mitral Regurgitation Curve:
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Rightward shift, Increased LVEDV + LVESV, but decreased SV
**Isovolumetric contraction abnormality |
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Chronic Mitral Regurgitation Curve:
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Increased LVESV + LVEDV
Increased SV d/t compensatory eccentric hypertrophy *Greater SV than normal, Starling's Law |
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Aortic Stenosis Pathophysiology:
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-Normal orifice: 2.5-3.5cm2
-Mild to moderate S/S: 0.7-0.9 -Critical: 0.5-0.7cm2 -Left ventricular outflow tract obstruction = impaired LV ejection, LV hypertrophy, LV failure -Myocardial thickening, decreased LV compliance, pressure overload = concentric hypertrophy |
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Aortic Stenosis Symptoms:
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dyspnea on exertion, angina, orthostatic hypotension, exertional syncope
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Aortic Stenosis Treatment:
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Inotropes (Digoxin, amiodarone), Na+ restriction, diurectics, valve replacement
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Aortic Stenosis Monitoring:
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auscultate systolic murmure 2nd ICS
ECG risk for ischemia Prominent A wave |
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Anesthesia Goals for Aortic Stenosis:
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Rate: 70-80
Rhythm: NSR Preload: maintain Afterload: maintain Contractility: maintain *sudden decrease in SVR will make the heart hyperdynamic and activate baroreceptor response -Avoid hypotension & bradycardia, attempts at CPR futile, Epidural over SAB for mild to moderate AS, opioid based GA, etomidate good, SVT with compromise: cardioversion, Amiodarone drug of choice for SVT, ventricular arrhytmias |
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Beta Blocker of Choice in Aortic Stenosis:
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Esmolol
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Vasopressor of Choice in Aortic Stenosis:
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Phenylephrine
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Aortic Stenosis Curve:
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-Shifted up, slightly right
-Increased LVEDP -LVEDV remain approximately normal -Decreased SV in critical AS |
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Pathophysiology of Aortic Regurgitation:
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Acute: trauma, aortic dissection, edocarditis
Chronic: congenital, rheumatic fever, syphillis Volume overload LV as volume ejected re-enters LV during diastole; Volume overload = chamber dilation = eccentric hypertrophy **Chronic AR has largest EDV of any heart dx |
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S/S of Aortic Regurgitation:
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-Mild: regurgitant volume less than 40% of SV
-Severe: regurgitant volume exceeds 60% of SV -Acute AR: hypotension, pulmonary edema, cardiovascular collapse -Chronic AR: diastolic murmur over 2nd ICS Right chest |
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Treatment of Aortic Regurgitation:
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Inotropes (digoxin, amiodarone), ACE inhibitors, Na+ restriction, valve replacement
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Monitoring for AR:
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Large V wave, indicitive of left ventricular dilation
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Anesthetic Goals for AR:
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Rate: increased slightly 80-100bpm
Rhythm: NSR Preload: maintain Afterload: slightly decreased Contractility: maintain SAB/epidural okay with prehydration, Ephedrine for hypotension |
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Acute AR Curve:
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Rightward Shift
Increased LVEDV Increased LVESV Increased LVEDP Decreased SV |
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Chronic AR Curve:
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Rightward shift
Dramatic increase in LVEDV Mild increase in LVEDP d/t increased ventricular compliance and contractility |
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Increased Preload Curve:
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-Filling increases
-Increased EDV without change in ESV -SV increases as a r/o Starling's Law -Requires increased myocardial O2 demand -Clinical example: fluid bolus, drug increased venous tone |
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Decreased Preload Curve:
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-Filling decreases
-Decreased EDV without change in ESV -SV decreases -Clinical examples: hypovolemia, NTG, diuretics |
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Increased Afterload Curve:
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Increased pressures
Increased EDV Increased ESV Shifts curve up and right Increased O2 demand Clinical: phenylephrine, SNS stimulation |
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Decreased Afterload Curve:
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Decreased Pressures
Decreased EDV Decreased ESV Shifts down and left Clinical example: Nitroprusside, hydralazine |
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Increased Contractility Curve:
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Higher Pressures
Smaller EDV Smaller ESV Increased O2 demand Increased SV Shifts up and left Clinical example: digoxin |
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Decreased Contractility Curve:
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Lower Pressures
Higher EDV Higher ESV Shifts down and right Decreased SV Clinical Example: CHF, Beta blockers, hypocalcemia |
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Hypertrophic Cardiomyopathy Curve:
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Hypertrophic LV
Left ventricular outflow obstruction Increased pressure Decreased EDV Decreased ESV Decrased SV |
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Tachycardia Curve:
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Decreased LVEDV
Decreased LVESV Decreased coronary perfusion Decreased SV |
