Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ ECG Findings (dependent on which leads are reversed) ++ Reversal of the left arm (LA) and right arm (RA) most common P, QRS, and T predominantly downgoing in lead I P, QRS, T upgoing in lead aVR Precordial leads unaffected Reversal of the leg leads (left leg [LL] and right leg [RL]) Does not commonly produce ECG changes because RL is used as a grounding electrode Reversal of LA-LL Transposition of leads I and II and leads aVF and aVL with reversal of lead III Reversal of RA-RL Transposition of aVR and aVL and inversion of lead II Incorrect precordial lead placement Isolated reversal of the usual R-wave progression from V1 to V6 +++ Pearls ++ If the ECG seems to have an unusual axis or appearance, especially when compared with a prior ECG on the same patient, consider a lead misplacement and repeat the tracing, confirming correct lead positions. A “reversed” lead I with normal-appearing V leads strongly suggests accidental limb lead reversal as opposed to dextrocardia. Dextrocardia features a “reversed” lead I, while QRS deflections in V4 to V6 appear small and downgoing. ++ FIGURE 23.54A Limb Lead Reversal (LA to RA). (ECG contributor: Michael L. Juliano, MD.) Graphic Jump LocationView Full Size||Download Slide (.ppt) ++ FIGURE 23.54B The P wave, QRS, and T wave are inverted in lead I in this ECG. Normal-appearing V leads in the 12-lead ECG above suggest limb lead reversal rather than dextrocardia. The arm leads were indeed reversed, and correction produced a normal-appearing 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? Download the Access App: iOS | Android 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.