Valve Regurgitation Echocardiographic Calculations Rami Khouzam, MDDefinitions/Equations: Continuity

Valve Regurgitation Echocardiographic Calculations Rami Khouzam, MD

Definitions/Equations: Continuity equation: Flow (SV) = LVEDV - LVESV = A x TVI (SV:Stroke Volume, A: Area, TVI:Time Velocity Integral) Flow 1(SV) = Flow 2 (SV) A1 x TVI 1 = A2 x TVI2

TVI Time Velocity Integral = stroke distance (cm). The distance over which blood travels in one cardiac cycle: the cycle velocity (cm/s) divided by time (s). Usually represents Mean gradient. Different than V (Velocity): m/s or cm/s. Usually represents Peak Instantaneous gradient.

Area Area =  r2 = 3.14 r2 (radius) = 0.785 d2 (diameter)

Flow 1(SV) = Flow 2 (SV) A1 x TVI 1 = A2 x TVI2 Inflow = Outflow A(MV) x TVI(MV) = A(LVOT) x TVI(LVOT)

Regurgitant Volume Regurgitant Volume (mL) = SV (Valve) - SV (systemic) Regurgitant Fraction Regurgitant Fraction (%) = SV (Valve) - SV (systemic) / SV (Valve)

Examples Mitral Regurgitation d(MV) = 3.5 cm d(LVOT) = 2.0 cm TVI (MV) = 10 cm TVI (LVOT) = 20 cm Calculate the Regurgitant Volume? A(MV) x TVI(MV) - A(LVOT) x TVI(LVOT) = 96 - 62 = 34 mL

Aortic Regurgitation d(MV) = 3.5 cm d(LVOT) = 2.5 cm TVI (MV) = 8 cm TVI (LVOT) = 25 cm Calculate the Regurgitant Volume? A(LVOT) x TVI(LVOT) - A(MV) x TVI(MV) = 122 - 76 = 46 mL

ERO Effective Regurgitant Orifice area (cm2) = Regurgitant Volume (mL) / TVI MR (cm) Effective Regurgitant Orifice area (cm2) = Flow (mL/s) / V MR (cm/s)

Example Mitral Regurgitation d(MV) = 3.5 cm d(LVOT) = 2.0 cm TVI (MV) = 10 cm TVI (LVOT) = 20 cm TVI (MR) = 120 cm ERO (cm2) = RV (mL) / TVI MR (cm) = 34/120 = 0.28 cm2 = 28 mm2

Aortic Regurgitation d(MV) = 3.5 cm d(LVOT) = 2.5 cm TVI (MV) = 8 cm TVI (LVOT) = 25 cm TVI (AR) = 188 cm ERO (cm2) = RV (mL) / TVI AR (cm) = 46/188 = 0.38 cm2 = 38 mm2

Tips Inflow > Outflow : MR Inflow < Outflow : AR

What is SEVERE Regurgitation?

More Examples A 65 yo M with NYHA class II symptoms. EF 55 %. d MV = 4 cm d LVOT = 2 cm TVI MV = 10 cm TVI LVOT = 20 cm V Ao = 1.2 m/s What’s next? a) Operate for MR b) Operate for AR c) Observe MR d) Observe combined AS/AR

Regurgitant Volume? A(MV) x TVI(MV) - A(LVOT) x TVI(LVOT) = 125.6 > 62.8 = 62 mL Inflow > Outflow: MR Answer: a

A patient has: d MV = 4 cm d LVOT = 2.5 cm TVI MV = 4 cm TVI LVOT = 25 cm V Ao = 2.5 This patient should have: a) Absent A2 b) Opening snap c) Quincke’s pulse d) Large V-wave e) Clubbing

A(MV) x TVI(MV) - A(LVOT) x TVI(LVOT) = 50.2 < 122.6 = 72 mL Inflow < Outflow: AR Answer: c