Relative Wall Thickness (RWT) Calculator

Calculate Relative Wall Thickness

Enter the posterior wall thickness and LV end-diastolic diameter using the same unit, preferably millimeters.

About Relative Wall Thickness

Relative Wall Thickness (RWT) is an echocardiographic geometric index used to describe left ventricular remodeling and geometry.

RWT is calculated from the posterior wall thickness and the left ventricular internal diameter at end-diastole:

RWT = (2 × PWd) / LVIDd

According to the ASE/EACVI chamber quantification recommendations, an RWT > 0.42 indicates increased relative wall thickness, while RWT ≤ 0.42 indicates normal relative wall thickness.

Important: RWT alone does not distinguish normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy. Complete LV geometric classification requires assessment of RWT together with LV mass index.

LV Geometric Pattern

LV geometry is determined by combining relative wall thickness with LV mass index.

LV Mass Index	RWT ≤ 0.42	RWT > 0.42
Normal LV mass	Normal geometry	Concentric remodeling
Increased LV mass	Eccentric hypertrophy	Concentric hypertrophy

This calculator reports RWT only. LV geometric pattern should not be assigned without an appropriate LV mass index assessment.

Technical Information

Measurement: PWd and LVIDd should be measured at end-diastole using the echocardiographic measurement approach appropriate for the selected acquisition method.

Units: PWd and LVEDD must use the same unit because RWT is a dimensionless ratio. This calculator displays the input unit as millimeters.

Calculation: The RWT is calculated using the unrounded input values. The displayed result is rounded to two decimal places.

References
1. Lang RM, Badano LP, Mor-Avi V, et al. Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28(1):1-39.

2. Marwick TH, Gillebert TC, Aurigemma G, et al. Recommendations on the use of echocardiography in adult hypertension: a report from the European Association of Cardiovascular Imaging and the American Society of Echocardiography. J Am Soc Echocardiogr.