Echo conference R4 우종신 R4 우종신

Case 1 한 O 태 ()

Evaluation of severity Planimetry of mitral orifice Planimetry of mitral orifice –only direct measurement of valve area and correlates closely with anatomic findings Pressure half-time method Pressure half-time method –Its validity may be questioned if loading conditions change or if the compliance of cardiac chambers is markedly abnormal Continuity equation Continuity equation –The ratio between SV in LVOT or RVOT and TVI of mitral flow –Risk of error –Valid only in the absence of significant MR PISA method PISA method –Can be used in the presence of significant MR –Technically demanding and requires multiple measurements

Classification of the Severity of Valve Disease in Adults Bonow et al ACC/AHA Practice Guidelines

Assessment of valve anatomy

Case 2 지 O 훈 ( )

Aortic Stenosis in Adults Causes: Causes: –Calcification of normal tri- leaflet valve Lipid accumulation, inflammation, calcification without commissural fusion Lipid accumulation, inflammation, calcification without commissural fusion –Congenital Bicuspid Valve abnormal flow traumatizes leaflets abnormal flow traumatizes leaflets –Rheumatic AS Fusion of commissures with scarring, valve often regurgitant as well Fusion of commissures with scarring, valve often regurgitant as well

Pathophysiology Gradual obstruction (over decades) Gradual obstruction (over decades) LV hypertrophies to adapt to systolic pressure overload to maintain wall stress (LaPlace’s Law) LV hypertrophies to adapt to systolic pressure overload to maintain wall stress (LaPlace’s Law) If hypertrophic process is inadequate, wall stress is increased and ejection fraction decreases If hypertrophic process is inadequate, wall stress is increased and ejection fraction decreases Increased wall thickness, Dec compliance causes inc LVEDP without chamber dilatation Increased wall thickness, Dec compliance causes inc LVEDP without chamber dilatation Depressed contractile state of myocardium may also be responsible for low EF (corrective surgery less beneficial) Depressed contractile state of myocardium may also be responsible for low EF (corrective surgery less beneficial)

Braunwald’s Heart Dis. 7 th Edition

Pathophysiology (con’t.) Atrial contraction important in filling of LV Atrial contraction important in filling of LV –With less compliant ventricle, less passive filling in early diastole –A fib in these pts may cause sudden clinical deterioration Adverse consequences to adaptation: Adverse consequences to adaptation: –Reduced coronary blood flow per gram of muscle –Limited coronary vasodilator reserve –Increased sensitivity to ischemic injury –Hemodynamic stress of tachycardia or exercise can produce maldistribution of coronary blood flow leading to subendocardial ischemia

Natural History Long asymptomatic “latent” period “Cardinal” symptoms of severe aortic stenosis DyspneaAnginaSyncope Sudden death Left ventricular dilatation and contractile failure EndocarditisArrhythmias Ventricular tachycardia Conduction system disease Atrial fibrillation

Symptoms and Prognosis Angina, syncope, heart failure Angina, syncope, heart failure Average survival 2-3 years Average survival 2-3 years High risk of sudden death with symptoms (without symptoms is <1%) High risk of sudden death with symptoms (without symptoms is <1%) Development of symptoms identifies critical point in natural history of AS Development of symptoms identifies critical point in natural history of AS

Associated Conditions In most pts with severe AS, impaired platelet function and decreased levels of von Willebrand factor can be demonstrated In most pts with severe AS, impaired platelet function and decreased levels of von Willebrand factor can be demonstrated Mechanical disruption of VW multimers during turbulent passage and from an interaction with platelets that triggers clearance Mechanical disruption of VW multimers during turbulent passage and from an interaction with platelets that triggers clearance Severity of coag abnl correlates with severity of AS Severity of coag abnl correlates with severity of AS Resolves after AVR Resolves after AVR Acquired von Willebrand syndrome associated with epistaxis, ecchymosis in 20% of pts Acquired von Willebrand syndrome associated with epistaxis, ecchymosis in 20% of pts

2D Echo in AS Useful for detecting valvular calcification, outlining leaflets, evaluating LV response to pressure overload Useful for detecting valvular calcification, outlining leaflets, evaluating LV response to pressure overload Doppler to calculate LV/AO pressure gradient from systolic AV velocity signal Doppler to calculate LV/AO pressure gradient from systolic AV velocity signal Continuity equation for valve area Continuity equation for valve area Color flow Doppler to look for concomitant AI/ evaluate PA Pressure Color flow Doppler to look for concomitant AI/ evaluate PA Pressure Remember: most common error is underestimation of disease severity due to non parallel intercept angle with high velocity jet Remember: most common error is underestimation of disease severity due to non parallel intercept angle with high velocity jet If LVOT diameter measurement is a problem, use dimensionless index If LVOT diameter measurement is a problem, use dimensionless index

Grading the Degree of Stenosis Indicator MildModerateSevere Jet velocity (m/sec) 4.0 Mean gradient (mmHg) 40 Valve area (cm2)> <1.0 Valve area index (cm/m2) <0.6 Normal aortic valve area is 3-4 cm 2 Normal aortic valve area is 3-4 cm 2 Gradient across valve normal until orifice area reaches less than half of normal

Indications for Cardiac Cath

Low-Flow/ Low Gradient AS -Patients with severe AS and low CO often present with low transvalvular gradient (due to low stroke volume) -These pts can be difficult to distinguish from low CO and mild-mod AS (pseudo AS, reduced AV opening due to low flow) -In both situations, low-flow state and low-pressure gradient contribute to valve area that is calcuated as severely low

Exercise Testing and AS -ST depression occurs in 80% of adults with AS and has no known prognostic significance -An abnormal hemodynamic response (hypotnesion or failure to increase BP with exercise) is considered a poor prognostic finding

Management Medical therapy has little to offer Medical therapy has little to offer SBE SBE Prophylaxis????? Prophylaxis????? Circulation, April 2007

Indications for AVR

Early Surgery??? Average peri-operative mortality from AVR in STS database is 3-4% isolated AVR, % for AVR and CABG Average peri-operative mortality from AVR in STS database is 3-4% isolated AVR, % for AVR and CABG Risk of SCD if asymptomatic <1% Risk of SCD if asymptomatic <1% ?? Irreversible myocardial depression/fibrosis during prolonged asx state ?? Irreversible myocardial depression/fibrosis during prolonged asx state

Aortic Balloon Valvotomy -Fracture of calcific deposits within the valve leaflets, stretching of annulus and separation of calcified commissures - >10% rate of serious acute complications -Restenosis and clinical deterioration occur within 6 to 12 months in most patients