The time at which the maximum gradient of the transmitral diastolic flow is halved can be used to measure Mitral Valve Area (MVA). This is the so-called pressure half-time (T ½) or PHТ (Pressure Half-time).

Empirically, if the Mitral Valve Area (MVA) is 1 cm2, then the Pressure Half-Time (PHT) is 220 s. From here we can find the MVA:

 

 

MVA - Mitral Valve Area. PHT - Pressure Half-Time

 

Assessment of mitral stenosis by the Mitral Valve Area (MVA):

• Mild > 1.5 cm2
• Moderate 1.0 - 1.5 cm2
• Severe < 1.0 cm2

 

Apical 4 Chamber View. Sample Volume position for examining the transmitral diastolic flow. Simulation By Echocardiography Online Simulator MyEchocardiography.com

 

Apical 4 Chamber View. CW doppler. Transmitral diastolic flow. Measurement of the Pressure Half-Time (PHT). Simulation By Echocardiography Online Simulator MyEchocardiography.com

 

 

ASE Guideline - Echocardiographic Assessment of Valve Stenosis

 

How to Simulate Assessment degree of Mitral Stenosis by PHT? >>>

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