TransmitralDruck

TransmitralDruck, commonly referred to as the transmitral pressure gradient, is the pressure difference between the left atrium and the left ventricle across the mitral valve during diastole. It represents the diastolic driving pressure for blood flow from the left atrium into the left ventricle when the mitral valve is open. In a healthy heart the gradient is small because left atrial pressure closely approximates the LV diastolic pressure.

Measurement and interpretation: The gradient can be measured invasively by recording left atrial and LV diastolic pressures with a catheter, or noninvasively by Doppler echocardiography. In Doppler assessment, the peak transmitral gradient can be estimated using the Bernoulli equation (ΔP ≈ 4v^2), where v is the peak velocity of the mitral inflow. The mean gradient over diastole is also reported and used to evaluate the severity of mitral stenosis. The gradient is flow-dependent and influenced by cardiac output, heart rate, and LV diastolic function; thus it must be interpreted in the clinical context.

Clinical significance: The transmitral gradient is central to evaluating stenotic mitral valve disease. A higher gradient indicates greater obstruction to forward flow, elevated left atrial pressure, and possible secondary pulmonary venous hypertension. In practice, gradient values are considered along with mitral valve area and other echocardiographic parameters to stage disease severity. The concept is less informative in isolated mitral regurgitation or in high-output states, where LV diastolic pressure and LA pressure relationships differ.

Terminology: The term TransmitralDruck is a direct, German-influenced rendering of transmitral pressure gradient; in common clinical usage, “transmitral gradient” or “transmitral pressure gradient” is preferred.