Assessing AV valve regurgitation: MR

Real Time Three-Dimensional Color Doppler Echocardiographic Characterization of Regurgitant Orifice Area in Children with Mitral Regurgitation.

 

We use colour 3D MPR to define the effective regurgitant orifice area in quantifying mitral regurgitation  in children, and to derive indices for assessing mitral regurgitation

Study protocol

All patients referred for evaluation of MR had Standard 2-D assessment

3-D assessment from the routine clinics. No sedation and images acquired like any transthoracic echo

Age/height/weight, clinical symptoms recorded.

Images were acquired using Phillips Sonos 7500/ IE33 using 4 MHz X4 transducer/ X3-1 transducer.

Full volume dataset of mitral valve and Full volume colour Doppler data set - MR were acquired.

Analysis performed with Q lab version-4.1

 

Severity of clinical symptoms were scored 1-3. 2-D echocardiographic findings were sored mild, moderate or severe (1-3) Pulmonary venous hypertension was scored from (1-3) using CXR by an experienced cardiac radiologist blinded to the clinical or echocardiographic findings.

Total clinical score was tabulated as Mild- 0-3, Moderate- 4-6, Severe > 7

 

Fig 1: Alignment of MPR planes along the regurgitant jet to obtain vena contracta area

 

 

Fig 2: Method of MPR for measuring mitral valve annulus area in systole and diastole.

 

 

Fig 4: Regurgitant Orifice area from MPR

Note the variation in the shape of venacontracta. Measuring the width shows enormous variation in diameter at different points, making the 2D venacontracta measurement unreliable.

 

Graph illustrating correlation between ROA and clinical severity score

Regurgitant Orifice Area is calculated from colour 3D MPR and plotted against Clinical Severity Score.

 

The inter observer variability for ROA was 0.966 and Intra observer variability was 0.952

 

Conclusion: Regurgitant orifice area as assessed by VCA indexed to body surface area gives the best correlation to the clinical severity of MR. This is highly reproducible and useful for monitoring the severity of MR in children