Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ ECG Findings ++ Increased amplitude of P wave without affecting duration (as commonly seen with left atrial abnormalities) Peaked P waves (> 2.5 mm) in leads II, III, aVF P-wave upward deflection > 1.5 mm in lead V1 or V2 ++ Pearls ++ Normal P-wave morphology has amplitude of < 2.5 mV (2.5 small vertical boxes) and duration (width) of < 120 ms (three small boxes). The right atrium depolarizes before the left atrium and therefore has the most effect on the 1st portion of the P wave. Right atrial enlargement is often associated with RVH, COPD, some congenital heart diseases, and pulmonary hypertension, and may be seen transiently with pulmonary embolus. ++ FIGURE 23.41A Right Atrial Hypertrophy. (ECG contributor: James V. Ritchie, MD.) Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) ++ FIGURE 23.41B The P wave in lead II (an inferior lead) is greater than 2.5 mm in amplitude (double arrow). Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) GET ACCESS TO THIS RESOURCE 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 Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. Access My Subscription GET ACCESS TO THIS RESOURCE Subscription Options Pay Per View Timed Access to all of AccessEmergency Medicine 24 Hour $34.95 (USD) Buy Now 48 Hour $54.95 (USD) Buy Now Best Value AccessEmergency Medicine Full Site: One-Year Individual Subscription $595 USD Buy Now View All Subscription Options