Left Atrial Pressure Calculator

Estimates left atrial pressure based on systolic blood pressure and maximum mitral regurgitation velocity measured by spectral Doppler.

Refer to the text below the tool for more information about the formula used and its interpretation.


Left atrial pressure (LAP) can be estimated via systolic blood pressure (SBP) and maximum mitral regurgitation velocity measured by spectral Doppler, provided that there is no significant gradient across the aortic valve.

Its monitoring can provide hemodynamic insight into left-sided cardiac structures.


Left Atrial Pressure = SBP – 4 x (MR VMAX)2

Where:

  • MR VMAX = maximum mitral regurgitation velocity
  • SBP = systolic blood pressure

Left atrial pressure normal range: 6 – 12 mmHg


Maximum mitral regurgitation velocity (MR VMAX)
Systolic Blood Pressure (SBP)
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Left Atrial Pressure Explained

Left atrial pressure (LAP) can be estimated via systolic blood pressure (SBP) and maximum mitral regurgitation velocity measured by spectral Doppler, provided that there is no significant gradient across the aortic valve.

The formula employed is:

Left atrial pressure = SBP – 4 x (MR VMAX)2

Where:

  • MR VMAX = maximum mitral regurgitation velocity
  • SBP = systolic blood pressure

Left atrial pressure defines the left ventricular filling pressure in patients who have systolic or diastolic left ventricular dysfunction or valvular heart disease. Its normal range varies between 6 and 12 mmHg, whilst its monitoring can provide hemodynamic insight into left-sided cardiac structures, for example when there is a concern about either:

  • LV function (systolic and diastolic);
  • Left atrial hypertension;
  • LV preload (acute right heart failure, pulmonary hypertension).

Left atrial pressure increases to augment left ventricular filling, resulting in pulmonary and systemic venous congestion.

 

References

Gorcscan J et al. Noninvasive estimation of left atrial pressure in patients with congestive heart failure and mitral regurgitation by Doppler echocardiography. Am. Heart J 1991; 121:858.

Nishimura RA et al. Determination of left-sided pressure gradients by utilizing Doppler aortic and mitral regurgitant signals: validation by simultaneous dual catheter and Doppler studies. JACC 1988; 11; 317.

Oh J, Seward JB, Tajik AJ. The Echo Manual 3rd edition. Lippincott, Williams, Wilkins. 2007.

Ge Z, Zhang Y, Fan D, Zhang M, Duran CM. Simultaneous measurement of left atrial pressure by Doppler echocardiography and catheterization. Int J Cardiol. 1992; 37(2):243-251.


Specialty: Cardiology

System: Cardiovascular

Abbreviation: LAP

Article By: Denise Nedea

Published On: July 15, 2020

Last Checked: July 15, 2020

Next Review: July 15, 2025