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Left atrial pressure
![Figure 4. Doppler measurement of left atrial mid-systolic pressure](https://echobyweb.com/wp-content/uploads/2021/02/la_midsystolic_pressure_methodology_eng.jpg)
Figure 4. Left atrial pressure (mid-systole) = radial artery systolic pressure – maximum pressure gradient of mitral regurgitation.
LAPms= Systolic radial artery pressure (cuff) – DP = 125 – 117= 8 mmHg.
Radial artery pressure measured by sphygmomanometry (125 mmHg in the example).
DP: pressure gradient between peak aortic systolic pressure and mid-systolic left atrial pressure, which can be calculated (simplified Bernoulli equation, P= v2 x 4) from the peak velocity of mitral regurgitation;
a: left atrial peak a pressure
AOP: Aortic pressure
LAP: left atrial pressure;
LAPms: left atrial mid-systolic pressure;
LVP: left ventricular pressure
v: left atrial peak v pressure.
Right panel: transesophageal evaluation of mitral regurgitation.
![Figure 5. Continuous wave Doppler of mitral regurgitation in left ventricular systolic dysfunction](https://echobyweb.com/wp-content/uploads/2021/02/la_midsystolic_pressure_elevated.jpg)
Figure 5. Transthoracic evaluation of mitral regurgitation associated with left ventricular systolic dysfunction (note reduced slope of velocity increase during isovolumic contraction), and elevated left atrial pressure.
Cuff radial pressure= 90 mmhg
LAPms= 90 – 57.2 = 32,8 mmHg.
![Figure 6. Continuous wave Doppler of mitral regurgitation in left ventricular systolic dysfunction](https://echobyweb.com/wp-content/uploads/2021/02/lap_mr_aumentata.jpg)
Figure 6. Transthoracic evaluation of mitral regurgitation associated with mild reduction of left ventricular systolic function and increased left atrial pressure.
Cuff radial pressure= 100 mmHg
LAPms= 100 – 67.6 = 32,4 mmHg