Sunday, February 4, 2018
Multifocal Atrial Tachycardia with Sinus Arrest
The rhythm begins as multifocal atrial tachycardia and has a period of sinus arrest. After the sinus arrest, then sinus rhythm resumes. The multifocal atrial tachycardia is characterized by a rate over 100 bpm and 3 or more P waves of differing morphology. You can see the differing morphology in 2nd, 3rd, and 5th complexes in lead II. The rhythm does not resume "on time" so we will call this a period of arrest rather than an exit block.