Home / Glossary / Relative wall thickness (RWT)
Indices & scales

Relative wall thickness (RWT)

An index of left-ventricular geometry — a marker of age-related heart remodeling

Echocardiography: measuring the wall thickness and diameter of the left ventricle

Relative wall thickness (RWT) is a calculated echocardiography measure that shows the ratio of wall thickness to left ventricular chamber size. Together with myocardial mass, it defines the type of cardiac remodeling.

RWT helps distinguish concentric and eccentric left ventricular hypertrophy.

Reference ranges

RWT is calculated with the formula: twice the posterior wall thickness divided by the end-diastolic chamber diameter. The threshold is 0.42:

Normal≤ 0.42
Elevated> 0.42
Important: RWT is interpreted only together with the left ventricular mass index.

What an elevated level means

An RWT >0.42 means the wall is thickened relative to the chamber. With normal myocardial mass this is concentric remodeling; with increased mass it is concentric hypertrophy (typical of pressure overload, for example in hypertension). This type is associated with a worse prognosis.

What a low level means

An RWT ≤0.42 with normal mass is normal cardiac geometry. With increased mass and RWT ≤0.42, one speaks of eccentric hypertrophy (volume overload, chamber dilation), which accompanies a rise in end-diastolic volume.

How the test is done

Two end-diastolic measurements are needed: the posterior wall thickness and the internal diameter of the left ventricle. Sometimes the interventricular septum thickness is added to the numerator. The calculation is done on transthoracic echocardiography.

What affects the value

  • The accuracy of measuring the wall and the chamber diameter.
  • The level and angle of the section on echocardiography.
  • The phase of breathing and the heart rate.

Calculate using this marker

Calculators where Relative wall thickness (RWT) is used directly:

Heart Age (Echo) A neural network reads five echocardiogram parameters — accurate to within ±5 years Open Heart Age AI analysis of your ECG — the biological age of your cardiovascular system Open

Frequently asked questions

What does RWT show?

RWT shows whether the heart wall is thickened relative to the size of its chamber. Together with myocardial mass, this divides cardiac remodeling into normal, concentric and eccentric.

What RWT is considered normal?

A value of 0.42 and below is considered normal. Above 0.42 is relative wall thickening, which is interpreted together with myocardial mass and blood pressure level.

Related terms

Echocardiography A heart ultrasound — an ultrasound study of the heart's structure and function Left ventricular hypertrophy (LVH) Thickening of the wall of the heart's main chamber from pressure overload Myocardial hypertrophy Thickening of the heart walls in response to increased load Interventricular septum (IVS) The muscular wall between the right and left ventricles of the heart End-diastolic volume (EDV) The volume of blood in the left ventricle at the end of diastole — before ejection Diastolic function The heart's ability to relax and fill with blood between contractions Blood pressure (BP) The pressure of blood on the artery walls, given as two values: SBP/DBP

Sources

  1. Left ventricular hypertrophy — Wikipedia
  2. Ventricular remodeling — Wikipedia
  3. ASE/EACVI Recommendations for Cardiac Chamber Quantification (2015)
info
This content is educational and does not replace consultation with a physician. Reference ranges may vary depending on the laboratory and method — rely on the ranges stated on your own test report.
← All glossary terms