Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ ECG Findings ++ QRS amplitude of ≤ 5 mm in all limb leads or QRS amplitude ≤ 10 mm in all precordial leads +++ Pearls ++ 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. Always check the calibration markings on the ECG to check for low standardization of the ECG machine as an etiology for the observed tracing. ++ FIGURE 23.55A Low-Voltage ECG with Underlying Atrial Flutter. (ECG contributors: Clifford L. Freeman, MD, and Nicole S. McCoin, MD.) Graphic Jump LocationView Full Size||Download Slide (.ppt) ++ FIGURE 23.55B QRS height is less than 5 mm in the precordial leads in this normally calibrated tracing. Graphic Jump LocationView Full Size||Download Slide (.ppt) Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.