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ECG Findings

  • QRS amplitude of ≤ 5 mm in all limb leads or QRS amplitude ≤ 10 mm in all precordial leads


  1. Differential diagnosis includes normal variant, low standardization of the ECG machine, pericardial or pleural effusion, obesity, anasarca, COPD/emphysema, cardiac infiltrate (tumor, amyloid), MI, myocarditis, cardiomyopathy, adrenal insufficiency, or hypothyroidism.

  2. Always check the calibration markings on the ECG to check for low standardization of the ECG machine as an etiology for the observed tracing.


Low-Voltage ECG with Underlying Atrial Flutter. (ECG contributors: Clifford L. Freeman, MD, and Nicole S. McCoin, MD.)


QRS height is less than 5 mm in the precordial leads in this normally calibrated tracing.

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