Sections View Full Chapter Figures Tables Videos 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 MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. 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 Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth