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What is mitral stenosis?
- Impedes blood flow from left atrium to left ventricle during diastole
- Results in left atrial enlargement and pressure; pulmonary congestion
- Etiology: usually rheumatic heart disease
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Clinical manifestations of mitral stenosis
- Dyspnea
- Atrial fibrillation
- Emboli from stagnant blood in left atrium
- Opening snap
- Diastolic murmur at apex (murmur occurs after S2, before S1 during diastole)
- Left atrial hypertrophy
- Back up into lungs, causing pulmonary edema
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What is mitral regurgitation?
- Backward flow of blood into left atrium during systole
- Etiology: MI, papillary muscle dysfunction, sever MVP (mitral valve prolapse), infective endocarditis, rheumatic heart disease
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What is acute mitral regurgitation?
- Usually MI
- Flash pulmonary edema
- New systolic murmur at apex (mitral valve should be closed during systole)
- Complications: left anterior descending
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What is chronic mitral regurgitation?
- Left atrium, left ventricle dilation (hypertrophy)
- Pulmonary congestion
- Holosystolic murmur at apex
- Will eventually lead to left ventricular failure with CHF
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What is mitral valve prolapse?
- Most common valve abnormality
- Structural abnormality in valve leaflet or papillary muscles results in prolapse of valve leaflets into left atrium during systole (leaflets are longer than normal, so they push up into atria)
- Usually benign
- Can cause mitral regurgitation or endocarditis
- Etiology: usually hereditary
- Usually identified on echo
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Clinical manifestations of mitral valve prolapse
- Can be asymptomatic
- Mid-systolic click (leaflets snapping up) with late systolic murmur
- Chest pain (not anginal)
- SVT(supraventricular tachycardia)
- PVCs (premature ventricular contraction)
- Palpitations
- V-tach
- Dizziness
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Treatment for mitral valve prolapse
- No treatment if minimally symptomatic
- Avoid stimulants, caffeine
- Beta blockers for palpitations
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What is aortic stenosis?
- Narrowing of aorta
- Obstruction of outflow from left ventricle during systole
- Decreased cardiac output
- Increased afterload, contractility and preload
- Myocardial hypertrophy
- Increased myocardial O2 demand
- Inability to increase cardiac output with exertion
- Etiology: most common senile calcification, congenital in younger, rheumatic heart disease
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Clinical manifestation of aortic stenosis
- Angina
- CHF
- Syncope
- S4 harsh systolic murmur at base (2nd ICS right sternal border)
- Patient will not tolerate tachycardia very well (incr in HR results in decr in preload, time in diastole, and O2 demand to myocardium)
- Patient will not tolerate hypovolemia either
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Treatment of aortic stenosis
- Beta blockers
- Avoid nitrates (decrease in preload will reduce outflow needed to force valve open; increases HR)
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What is aortic regurgitation?
- Retrograde blood flow from aorta back into left ventricle during diastole
- Causes left ventricle dilation/hypertrophy
- Valve does not close completely during diastole
- Eventually leads to dilated left atrium and pulmonary congestion
- Acute etiology: endocarditis, trauma, aortic dissection, life threatening emergency can lead to CV collapse
- Chronic etiology: rheumatic heart disease, congential bicuspid aortic valve
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Clinical manifestation of aortic regurgitation
- Water hammer pulse (quick collapse in diastole; strong collapsing pulse)
- Diastolic murmur at base
- CHF
- Exertional dyspnea
- Orthophnea
- Paroxysmal noctural dyspnea
- High SBP, low DBP (heart has to really fill up and push hard to get blood out, then it collapses)
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Diagnosing valvular heart disease
- Echocardiogram (information on valve structures, functions and chamber size)
- Cardiac cath (quantifies size of valve and chamber pressures; used prior to planned surgical correction)
- Multiple valve disorders can co-exist (i.e. can have both aortic stenosis and mitral regurgitation)
- Intensity of a murmur does not necessarily indicate severity of a valve problem (may not be enough blood to create a loud murmur)
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Treatment of valvular heart disease
- Conservative (monitor cardiac function, prevent endocarditis, treat CHF)
- Percutaneous transluminal balloon valvuloplasty (cardiac cath ballon separates stenotic valve leaflets; opens up valve)
- Valve repair (open with sternotomy with cardiopulmonary bypass; surgeon repairs damaged valve without use of prosthetics)
- Mechanical valves (increased risk of thromboembolism; requires life long anticoagulation therapy; INR s/b 2.5 to 3.5)
- Biological valves (less thrombogenic but do not last as long as mechanical valves; less likely to shred red blood cells)
- With valve replacement, concerned with clotting and vegetation caused by endocarditis
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Nursing care for valvular heart disease
- Assessment: vitals, O2 sat, heart sounds, lung sounds, cardiac output
- Treatment of CHF
- Post-op valve repair or replacement: similar to post CABG patient; manage volume post-op, cardiac output, manage invasive lines, manage airway
- Patient education: anticoagulation, endocarditis prophylaxis (especially for mechanical valves)
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