The most common narrow complex regular tachycardias are sinus tachycardia, atrial flutter, atrial tachycardia that blocks, and paroxysmal supraventricular tachycardia. Carotid sinus massage is useful in differentiation. Irregular narrow-complex tachycardias are usually atrial fibrillation.
Read moreHow is the QRS complex described in atrial fibrillation?
The diagnosis of atrial fibrillation is confirmed with a standard 12-lead ECG. P waves are absent, coarse “fibrillatory waves” can frequently be seen and sometimes no atrial activity can be identified. The QRS complexes are “irregularly irregular ”, with varying R-R intervals.
Read moreHow do you detect atrial flutter on ECG?
ECG features of atrial flutter
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