Low voltage
Also calledLow QRS voltage · Low-voltage ECG · Diminished QRS amplitude
Definition
Abnormally small QRS complexes, defined as a QRS amplitude under 0.5 mV (5 mm) in all limb leads and/or under 1.0 mV (10 mm) in all precordial leads. Causes fall into two groups: those outside the heart that damp the signal, such as a large pericardial or pleural effusion, emphysema or COPD, morbid obesity, and anasarca or other generalized edema, and those that reduce the voltage the heart itself generates, such as infiltrative heart disease. Severe hypothyroidism (myxedema) can also cause it.
Sources
- Usoro AO, Bradford N, Shah AJ, Soliman EZ. Risk of mortality in individuals with low QRS voltage and free of cardiovascular disease. Am J Cardiol. 2014;113(9):1514-1517. doi.org/10.1016/j.amjcard.2014.02.006
- Samesima N, God EG, Kruse JCL, et al. Brazilian Society of Cardiology guidelines on the analysis and issuance of electrocardiographic reports - 2022. Arq Bras Cardiol. 2022;119(4):638-680. doi.org/10.36660/abc.20220623
- Madias JE. Low QRS voltage and its causes. J Electrocardiol. 2008;41(6):498-500. doi.org/10.1016/j.jelectrocard.2008.06.021
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.