Pisa

_=2Tfr2

3*D Isovelocity 2nd Isovelocity 1ST Isovelocity = PISA

Regurgitant Flow = 21fr2 x Vauas

Fig. 24. Proximal isovelocity surface area (PISA).

severity itself, but should be further integrated with global cardiac function and the patient's clinical status. Newer methods of assessing MR severity show promise, e.g., 3D echocardiography and power Doppler imaging, but are not yet routinely used in clinical practice (Fig. 34; please see companion DVD for corresponding video).

surgical considerations in mr

Anatomical Mechanisms of MR

Precise determination of the mechanism of MR results is necessary for successful reconstructive surgery of the mitral valve. Thus, the Carpentier's functional classification is often used (Fig. 35).

Fig. 25. Mitral regurgitation severity: proximal isovelocity surface area (PISA) method. Step 1: select the best apical four-chamber view (A4C) to indentify the region of interest—the regurgitant mitral valve (panel 1). Step 2: lower imaging depth, then zoom (panel 2). Step 3: apply color Doppler, then narrow color sector scan (panel 3). Step 4: shift color flow baseline on color Doppler scale downward (to lower Nyquist limit) to approx 40 cm/s. This optimizes the aliasing velocities enables the PISA hemispheric zone bigger and more measurable (panel 4). Step 5: record the Nyquist limit on the color Doppler Scale. This is the aliasing velocity of the PISA. Scroll through cine loop and optimize largest PISA (mid-systole) and measure radius (panel 5). Step 6: obtain the maximum velocity across the mitral regurgitation jet using continuous-wave Doppler (panel 6). (Please see companion DVD for corresponding video.)

PISA Method: Continuity Equation

2lPPStx VelocityP1SA = EROAx Velocity™ J.,

EROA = 6.28 x i^saX Alias Velocity

Fig. 26. Proximal isovelocity surface area (PISA) method: calculation of effective regurgitant orifice area (EROA) by the continuity equation. The PISA method is used to calculate the EROA according to the principle of conservation of mass. The continuity equation is used to calculate the EROA from the variables measured in Fig. 25.

Proximal Isovelocity Surface Area

Fig. 25. Mitral regurgitation severity: proximal isovelocity surface area (PISA) method. Step 1: select the best apical four-chamber view (A4C) to indentify the region of interest—the regurgitant mitral valve (panel 1). Step 2: lower imaging depth, then zoom (panel 2). Step 3: apply color Doppler, then narrow color sector scan (panel 3). Step 4: shift color flow baseline on color Doppler scale downward (to lower Nyquist limit) to approx 40 cm/s. This optimizes the aliasing velocities enables the PISA hemispheric zone bigger and more measurable (panel 4). Step 5: record the Nyquist limit on the color Doppler Scale. This is the aliasing velocity of the PISA. Scroll through cine loop and optimize largest PISA (mid-systole) and measure radius (panel 5). Step 6: obtain the maximum velocity across the mitral regurgitation jet using continuous-wave Doppler (panel 6). (Please see companion DVD for corresponding video.)

Carpentier's Functional Approach to Mitral Regurgitation

The Carpentier functional classification of MR is based on the opening and closing motions of both leaflets. Normal mitral leaflet coaptation requires coordination of many structures including a normal-sized LV

and a chordal apparatus that is not calcified and is well tethered to the mitral leaflets that coapt well (Fig. 35).

Functional Classification: Type I

MR that occurs despite normal leaflet motion is termed type I MR. This can be owing to annular dilatation seen

Pisa Mitral Valve
Fig. 27. Regurgitant volume and regurgitant fraction.
Mitral Valve Pisa Measurements

Fig. 28. (A) Transesophageal echocardiography (TEE) midesophageal view at omniplane 0° showing partial flail of posterior mitral valve leaflet. (B) Color Doppler imaging shows severe mitral regurgitation with proximal convergence zone with an anteriorly directed jet. Color Doppler scale set at 59 cm/s. (C) Color Doppler scale is then shifted upward (on TEE) to 43 cm/s showing clearly defined proximal isovelocity surface area (PISA) measuring 0.966 cm, consistent with severe mitral regurgitation.

Fig. 28. (A) Transesophageal echocardiography (TEE) midesophageal view at omniplane 0° showing partial flail of posterior mitral valve leaflet. (B) Color Doppler imaging shows severe mitral regurgitation with proximal convergence zone with an anteriorly directed jet. Color Doppler scale set at 59 cm/s. (C) Color Doppler scale is then shifted upward (on TEE) to 43 cm/s showing clearly defined proximal isovelocity surface area (PISA) measuring 0.966 cm, consistent with severe mitral regurgitation.

Table 10 PISA Assumptions and Pitfalls

• Accurate measurements (subject to error, errors are squared, interobserver variability)

• Unconstrained flow (constrainment exists)

• Circular point-like orifice (regurgitant orifice irregular, often "smiley" shaped)

• Flat regurgitant orifice (actual orifice not flat)

• PISA is a hemisphere (PISA is more a hemi-ellipse)

• Constant orifice (PISA calculation is an instantaneous measurement, but PISA—like the cardiac cycle—is dynamic)

• PISA method not suitable for eccentric jets, or concomitant mitral stenosis

Pulmonary artery systolic flow reversal jààitih

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Responses

  • Ursula
    Where do you take the radius on pisa on echocardiogram?
    4 months ago
  • sophie junker
    How is pisa done done for mitral stenosis on echocardiogram?
    4 months ago

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