MAT

Multifocal atrial tachycardia

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Multifocal atrial tachycardia is defined as three or more different types of P waves occuring at a rate more than 100 per minute. In the second rhythm strip there is a pause before the onset of sinus rhythm after the tachycardia terminates. This could be due to down regulation of the If current (funny current or pacemaker current) in the sinus node due to the tachycardia or due to a block atrial ectopic beat which is not very evident as it is superimposed on the T wave.

Multifocal atrial tachycardia and blocked atrial ectopic beat

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Sinus rhythm is seen in the middle portion of the ECG, while tachycardia is seen at both ends. Following the fourth beat in the rhythm strip, there is a pause due to a non conducted atrial ectopic beat (blocked atrial ectopic). The nearest differential diagnosis of a multifocal atrial tachycardia is atrial fibrillation (paroxysmal atrial fibrillation in this case). Multifocal atrial tachycardia (MAT) can occur in this with chronic obstructive lung disease.