Which rhythm is defined by irregular atrial activity with P waves of varying morphology and irregular atrial rate?

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Multiple Choice

Which rhythm is defined by irregular atrial activity with P waves of varying morphology and irregular atrial rate?

Irregular atrial activity with P waves of varying morphology and an irregular atrial rate is characteristic of multifocal atrial tachycardia. This rhythm comes from several different atrial pacemaker sites, so each beat can have a distinct P-wave shape. You’ll see at least three different P-wave morphologies, and the atrial rate is over 100 with an irregular rhythm, causing the ventricular response to be irregular as well. This fits best because other rhythms have different hallmarks. Atrial fibrillation shows no discrete P waves at all—the atrial activity is chaotic and the baseline is rapidly fibrillatory. Atrial flutter has a regular, organized atrial activity with sawtooth flutter waves, usually at a single fixed rate around 250–350 bpm. Sinus tachycardia has a normal P-wave shape before each beat and a regular rhythm, just faster than normal.

Irregular atrial activity with P waves of varying morphology and an irregular atrial rate is characteristic of multifocal atrial tachycardia. This rhythm comes from several different atrial pacemaker sites, so each beat can have a distinct P-wave shape. You’ll see at least three different P-wave morphologies, and the atrial rate is over 100 with an irregular rhythm, causing the ventricular response to be irregular as well.

This fits best because other rhythms have different hallmarks. Atrial fibrillation shows no discrete P waves at all—the atrial activity is chaotic and the baseline is rapidly fibrillatory. Atrial flutter has a regular, organized atrial activity with sawtooth flutter waves, usually at a single fixed rate around 250–350 bpm. Sinus tachycardia has a normal P-wave shape before each beat and a regular rhythm, just faster than normal.

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