Hemodynamic assessment using Echocardiography Geu-Ru Hong MD Ph

Hemodynamic assessment using Echocardiography Geu-Ru Hong, MD, Ph. D Cardiology Division, College of Medicine, Yonsei University, Seoul, Korea

Echocardiography Anatomic Information Functional Information

Echocardiography Systolic Functional Information Wall Motion Analysis Diastolic Function Valvular Function Hemodynamic Function

Doppler Echocardiography • • • Pressure Gradient Chamber Pressure Measurement Calculation of Stenotic Valve Area Calculation of Regurtgitant Volume Calculation of Flow Volume Assessment of LV Diastolic Function

- Christian Johann Doppler(1842) Christian Doppler was an Austrian mathematician who lived between 1803 -1853. He is known for the principle he first proposed in Concerning the coloured light of double stars in 1842. He hypothesised that the pitch of a sound would change if the source of the sound was moving. He didn't test this hypothesis until 1845.

Doppler Effect - Christian Johann Doppler(1842) -

Doppler shift = f = fr-f 0 = 2 f 0 Vcos /C f 0 = transmitted freq. fr = reflected freq. V = velocity of RBC C = speed of ultrasound in blood

Zero line

Laminar flow Turbulent flow Doppler signal

Continuous wave(CW) Doppler • continuous measurement using different element • No depth Pulsed wave(PW) Doppler • measure velocity at certain depth • sample volume • Low velocity

Continuous Wave Doppler Pulsed Wave Doppler

Pulsed-wave Continous-wave Measure specific blood flow velocity by placing the “sample volume” at the region of interest Measures blood-flow velocities along the axis of the entire ultrasound beam Maximal measurable velocity without Aliasing is usually < 2 m/s able to measure high velocities < 9 m/s Suited for measuring low velocity at a particular intracardiac location Suited for measuring peak velocities across intracardiac orifices

Doppler Echocardiography History • 1959 Satomura detected arterial flow • 1961 Franklin measurement of flow velocity • 1973 Johnson located place of cardiac murmur • 1978 Hatle measured PG between LA and LV • 1982 Namekawa real time color Doppler using autocorrelator technique

Hemodynamic data that can be obtained with Doppler echocardiography Volumetric measurements Stroke volume and cardiac output Regurgitant volume and fraction Pulmonary-systemic flow ratio(Qp/Qs) Pressure gradients Maximal instantaneous gradient Mean gradient Valve area Stenotic valve area Regurgitant orifice area Intracardiac pressure Pulmonary artery pressure, LA pressure, LVEDP

Pressure gradient from Doppler measurements • Pressure gradient • Modified Bernoulli Eq. P = 4 V 2 Limitation of Doppler velocity (and pressure gradient derived thereof) Volume and Rate-dependent

Time Velocity Integral • Calculate area under the Doppler curve over a specified period of time • Distance(cm) that blood travels with each stroke Normal : aortic TVI 18 - 22 cm mitral TVI 10 - 13 cm

Flow distance(cm) Area (cm 2) Area x Flow distance = Flow volume

Orifice Area(CSA) • r 2 = 0. 785 x D 2 Normal : aortic annulus 1. 8 – 2. 2 cm mitral annulus 3. 0 – 3. 5 cm

Stroke Volume TVI x Area

Stroke Volume, Cardiac Output, Cardiac Index • SV(cc) = TVI(cm) x CSA(cm 2) • CO(liters/min) = SV(cc) x HR(beats/min) • CI(liters/min/m 2) = CO(liters/min) x BSA(m 2)

Estimation of Left Ventricular Enddiastolic Pressure Systemic BP : 160/80 mm. Hg 4 m/s Diastolic BP=LVEDP+(AR enddiastolic velocity)2 x 4 80 mm. Hg= LVEDP + 42 x 4 LVEDP= 80 -64=16 mm. Hg Aortic Regurgitation

Continuity Equation Calculation of AVA x TVIAV LVOTAREA x TVILVOT TVI LVOT AVA=d 2 x 0. 785 x TVI AV

The Reason for Shorter PHT in Severe AR

CW Doppler of Aortic Regurgitation pressure half time PHT: 200 ms 5 m/s PHT: 540 ms

Pressure Half Time in MS LV LA Mild MS Severe MS

Pressure Half Time in MS Vmax 2 m/sec V 1/2 max Vmax = 2 m/s V 1/2 max = Vmax / 1. 4 = 1. 43 m/s PHT MVA PHT: 220 msec = 220/220 = 1. 0 cm 2

Simultaneous Measurement of Doppler and Catheter Derived Pressures LV PCWP DPG: 9. 6 mm. Hg DPG: 10 mm. Hg

Pressure = 4 x 2 V

LV RV RA CS Estimation of RV Systolic Pressure Assume RAP 10 mm. Hg RVSP=(TR)2 x 4+ RAP =32 x 4 +10 =36 + 10 =46 mm. Hg 3 m/sec

Estimation of LA Pressure Blood Pressure = 100/80 mm. Hg Systolic BP=(MR)2 x 4 + LAP 100 mm. Hg= 4. 52 x 4+ LAP=100 -81 =19 mm. Hg 4. 5 m/s

Severe Pulmonary Hypertension TR Velocity PR Velocity 3 m/s 4. 5 m/s M-mode of PV

Estimation of Pulmonary Arterial Pressure Assume RAP 10 mm. Hg TR: 4. 5 m/sec PR: 3 m/se c PASP =TR 2 x 4 + RAP =4. 52 x 4 + 10 =81 + 10 = 91 mm. Hg PADP =PR 2 x 4 + RAP =32 x 4 + 10 =36 + 10 = 46 mm. Hg

Meaurement of dp/dt

Intracardiac pressures • RV or PA systolic pr. = 4(TR sys. velocity)2 + RA pressure • PA diastolic pr. = 4(PR end diastolic velocity)2 + RA pressure • LA pressure = Systolic BP – 4(MR systolic velocity)2 • RV systolic pr. = Systolic BP – (VSD velocity)2

Transmitral Pressure Gradient Mean Pressure Gradient

Doppler-derived vs Catheter-derived Continuous-wave Doppler peak velocity Aortic Valve Measure velocity at the level of the vena contracta Invasive catheterization Maximum Instantaneous gradient Peak to Peak gradient Different ! Measure the differences between LV and the fully recovered static pressure in the aorta

Measurement of jet area Jet area(cm 2) Grade 1 : 4 - 8 Grade 2 : 8 - 12 Grade 3 : 12 - 16 Grade 4 : > 16

Quantification of MR - Volumetric method MV Reg V = MV flow – LVOT flow AO LA MV RF = MV Reg V/MV flow x 100 MV Reg V : mitral valve regurgitant volume MV RF : mitral valve regurgitant fraction(%) LV

Quantification of MR - PISA method r = 1. 1 cm Alias Velocity = 29 cm/sec MR Velocity = 4. 3 m/sec r ERO = 6. 28 (1. 1)2 29 430 RV = ERO MR TVI = 0. 51 114 = 58 ml