cath measurement of stenotic aortic valve area心脏凯斯测量狭窄的主动脉瓣区（ppt53）课件

Cardiac Cath Measurement of Stenotic Aortic Valve Area Ryan Tsuda, MD Case Report: nCC: Shortness of Breath nHPI: 62 y/o Caucasian male, without previous significant medical history, presents with 6-8 months of progressively worsening dyspnea. Recalls 1 month h/o new onset leg and belly swelling. Describes 2 pillow orthopnea and occasional PND. Denies CP, syncope, or lightheadedness. Case Report: nPMHx: Childhood murmur nMeds: None nAll: NKDA nSHx: Denies etoh, smoking, or illicit drugs nFMHx: Did not have a relationship with his family, and therefore, is was not familiar with their medical problems. Case Report: nPE: 97.6 115 159/109 26 100%2L Gen: Middle aged male with mild respiratory distress Neck: Short and thick, No obvious jvd CV: Tachycardic w/ RR, nl S1 S2, +S3, 2/6 crescendo decrescendo systolic murmur at URSB Pulm: Mild bilateral base crackles Abd: Diffuse abdominal wall edema, +shifting dullness GU: +scrotal edema Ext: 3+ Bilateral pitting edema Case Report: nNa 143, K 4.3, Cl 105, CO2 30, BUN 23, Cr 1.3, Glu 108 nWBC 10.6 w/ NL diff, Hg 15.8, Hct 50.8, Platelets 219,000 . nTprot 6.7, Alb 3.5, Ast 66, Alt 57, Alkphos 127, Tbili 1.2 nUA: +protein nBNP 3690 Case Report: nEKG: STach 115, LVH nCXR: CM, Increased PVC, Small bil pleural effusions Initial A/P: New CHFStarted on Natrecor, Lasix, Digoxin, Captopril, and AldactoneMore to follow Cardiac Cath Measurement of Stenotic Aortic Valve Area nAs valvular stenosis develops, the valve orifice produces more resistance to blood flow, resulting in a pressure gradient (pressure drop) across the valve Gorlin Formula nCalculates cardiac valvular orifice area from flow and pressure-gradient data nIncorporates 3 preexisting formulas Gorlin Formula n1.) Torricellis Law (flow across a round orifice) F = AVCc F = Flow Rate A = Orifice Area V = Velocity of Flow Cc = coefficient of orifice contraction (compensates for the physical phenomenon, that except for a perfect orifice, the area of a stream flowing through an orifice will be less than the true area of the orifice) Gorlin Formula n2.) Relates pressure gradient to velocity of flow V2 = (Cv)2 x 2gh Cv = coefficient of velocity, corrects for energy loss as pressure energy is converted to kinetic energy g = acceleration due to gravity (980 cm/sec/sec) h = pressure gradient in cm H2O Gorlin Formula nCombining the two equations, yields: F A = - (C)(44.3) (sq root of h) C = Empirical constant incorporating Cv and Cc, and accounting for h adjusted to units of mmHg, and correcting calculated valve area to actual valve area as measured at surgery or autopsy. Using this constant, the maximum derivation of calculated valve area from measured valve area was 0.2 cm2. Gorlin Formula nSince antegrade aortic flow occurs only in systole, F is the total CO during which there is forward flow across the valve F = CO/(SEP)(HR) F (cm3/sec) CO (cm3/min) SEP (sec/beat) HR (beats/min) *SEP (systolic ejection period) begins with aortic valve opening and proceeds to the dicrotic notch or other evidence of valve closure. Gorlin Formula nThus, the final Gorlin equation for the calculation of valve orifice area (in cm2) is: CO/(SEP)(HR) nArea = - 44.3(C)(sq rt of pressure gradient) Where C = empirical constant For MV, C = 0.85 (Derived from comparative data) For AV, TV, and PV, C = 1.0 (Not derived, is assumed based on MV data) Alternative to the Gorlin Formula *A simplified formula for the calculation of stenotic cardiac valves proposed by Hakki et alCirculation 1981. Tested 100 patients with either AS or MS. *Based on the observation that the product of HR, SEP or DFP, and the Gorlin equation constant was nearly the same for all patients measured in the resting state (pt. not tachycardic). Values of this product were close to 1.0. *Calculations somewhat comparable Aortic Valve Area (cm2) nCritical AS: 250 dynes sec cm -5 are more likely to have significant AS, while those with resistance 200 dynes sec cm -5 are less so. Case Report nEcho Clips Case Report: 2D-Echo: LVEF 15-20% Severely reduced RVEF 4-Chamber DCM Abnormal LV Relaxation Severe Aortic Stenosis (PK AV Vel 4.3 m/s, Mean AV gradient 33 mmHg, AV area 1.0 cm2) Mild Aortic Insufficiency, Mild Tricuspid Regurgitation, and Mild Mitral Regurgitation Gorlin Formula LHC + RHC nCO 4.2 L/min nCI 2.2 L/min/m2 nRA pressure 12 nRV pressure 65/10-13 nPA pressure 56/41 nWedge 32-35 nLV pressure 200/35 nAortic pressure 150/85 nSimultaneous pressure gradient 48.5 mmHg nValve Flow 178 cm3/sec nMean gradient 60 mmHg n Aortic Valve Area 0.52 cm2 nDistal LCX 80-90% prior to large PDA filling via right to left collaterals Case Report *LV to Aorta Pullback Case Report *Simultaneous pressure gradient Case Report *Planimetry of shaded area yields pressure gradient Case Report: nHospital Course and Discharge Plan: *Achieved adequate diuresis in the hospital *Referral to CT Surgery for possible AVR and 1V-CABG Summary: nCath measurement of aortic valve stenosis is based on the Gorlin formula. nProper calibration and procedural techniques using the catheter is important in acquiring accurate cardiac output and pressure gradients. nDuring low cardiac output states (i.e. CHF), may need to use adjunctive techniques to acquire reliable hemodynamic data to calculate accurate aortic valve area, and in turn, make the appropriate recommendation regarding valve