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View TSDA Curriculum Online for this topic |
| 1. Morphology a) Calcified Aortic Stenosis · Congenitally bicuspid or unicuspid, fused commissures, heavy calcification, age 50-70 b) Rheumatic Aortic Stenosis · Fibrous thickening, 3-cusp valve, mild calcification, rheumatic fever history in 1/2 c) Degenerative Aortic Stenosis · Diffuse nodular calcification, 3-cusp valve, no commissural fusion |
| 2. Aortic Valve Incompetence · Cusp prolapse or cicatricial shortening of cusps with rolled edges · Annulo-aortic ectasia is a disease of the aorta rather than the valve itself · Dilation of sinus aorta, cystic medial necrosis, failure of coaptation of cusps |
| 3. Symptoms and Diagnosis a) Aortic Stenosis · Dyspnea, angina, syncope in 1/3 · Angina more common with CAD · Severe AS = LV to Ao gradient greater than 50 mmHg or aortic valve area less than 1.2 cm2/M2 b) Aortic Incompetence · CHF symptoms, angina 1/4, syncope rare · Severe AI = LV enlargement, calculated LV end systolic pressure greater than 50mm Hg, EF less than 40%, calculated fiber shortening less than 0.6 cm/sec |
| 4. Natural History - Stenosis a) Hemodynamically severe, symptomatic or asymptomatic · Sudden death risk high · Immediate operation is indicated b) Hemodynamically mild or moderate, asymptomatic · 50% event free for 4 years · Operation is not urgent, but patients should be followed carefully as the disease advances rapidly c) Hemodynamically mild or moderate, symptomatic · One-third will die within 4 years · Prompt operation is indicated |
| 5. Natural History - Incompetence a) Latent period to cardiac decompensation is long · Sudden death is not common · Once deterioration begins, the LV fails rapidly b) Symptomatic patient with CHF, angina, syncope · Prompt operation is indicated c) Asymptomatic patient · Follow carefully for LV enlargement or decreased LV function by ECHO or MUGA · Operate at an appropriate time |
| 6. Associated Coronary Artery Disease · Treat significant coronary artery disease at the time of surgery even if asymptomatic · CABG reduces risk of AVR and improves long-term survival · Coronary angiography is indicated in all patients older than 45 years who will be having AVR |
| 7. Ventricular Performance After AVR · AVR may improve LV performance · Pre-op LV dysfunction is the strongest predictor of post-op dysfunction (60%) · Microscopic changes in myocardium may persist despite improvement in symptoms and reduction in heart size |
| 8. Age and AVR · Advanced age most common predictor of survival and cardiac events · AVR very effective treatment even in patients over age 70 or 80 · Even the best patients over age 80 have reduced reserve |
| 9. Choice of Replacement Device · Age less than 55 years - Aortic allograft or pulmonary autograft · Age between 55-75 years - Mechanical prosthesis · Age greater than 75 years - Porcine heterograft, stented or stentless · Allografts and autografts enlarge the orifice by about 2 mm, porcine heterografts reduce valve size by about 2 mm, and mechanical valves reduce valve size by about 5-8 mm |
| 10. Size of Prosthesis for AVR a) 19 mm · Prohibitively high LV/Ao gradient · Enlarge the aortic root or perform Ross procedure instead b) 21 mm · Adequate size if BSA 1.5-1.7 M2 and patient is sedentary · If BSA greater than 1.7 M2 = enlarge the aortic root (10 year survival 80% vs 60%) c) 23 mm or larger · Acceptable LV/Ao gradient in all patients |
| 11. Survival After AVR a) Early (hospital) death - 3-6% b) Time-related survival · 5 years - 75% · 10 years - 60% · 15 years - 40% c) Mode of death · Early due to CHF, hemorrhage, infection, CVA · Sudden - 20% · Device related - 20% |
| 12. Risk Factors for Survival after AVR · Advanced age · Functional status (NHYA class) · Depressed LV function (aortic incompetence) · Coronary artery disease · Presence of endocarditis · Aneurysm of ascending aorta · Mismatch of prosthesis and body size |