Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content +++ ECG Findings ++ Irregularly irregular narrow-complex tachycardia at a rate > 100 bpm Multiple P-wave morphologies, with at least three distinct P-wave morphologies in the same lead Varying PP, PR, and RR intervals +++ Pearls ++ Multiple atrial foci are capable of acting as pacemakers. When irritated by stretching, medications, or certain acute medical conditions, these foci compete in pacing the atria. The different atrial foci produce P waves of different morphologies. Since the atrial foci vary in distance to the AV node, PR intervals vary. Multifocal atrial tachycardia (MAT) usually results from exacerbation of another condition that produces distention or irritation of the atria. The most common cause of MAT is chronic obstructive pulmonary disease (COPD) exacerbation. Treatment of the underlying condition should correct the arrhythmia. Even though MAT itself is not usually fatal, it is a poor prognostic sign. ++ FIGURE 23.30A Multifocal Atrial Tachycardia. (ECG contributor: James V. Ritchie, MD.) Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) ++ FIGURE 23.30B Multiple P morphologies (arrowheads), varying PR intervals (lower double arrows), and varying R-R intervals (upper double arrows) with heart rate greater than 100 bpm. 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