Atrial Rhythms

Atrial fibrillation atrial rate

Up to 350 bpm

Atrial fibrillation ventricular rate

Varies from bradycardic to tachycardic

Atrial fibrillation rhythm

Irregularly irregular

Atrial fibrillation P-wave

Absent or non-discernible, fibrillatory waves

Atrial fibrillation PRI

None, unable to identify P-waves

Atrial fibrillation QRS

< 0.12 seconds

Atrial fibrillation etiology

Sudden onset, chronic cases may be intermittent and associated with increased age, middle-aged athletes susceptible, diabetes and hyperthyroidism may contribute

Atrial fibrillation clinical significance

Decreased cardiac output, may cause pulmonary edema/congestive heart failure, prone to blood clots

Atrial flutter atrial rate

250–300 bpm

Atrial flutter ventricular rate

Typically around 150 bpm

Atrial flutter rhythm

Regular

Atrial flutter P-wave

Sawtooth pattern, upright, multiple for every QRS complex

Atrial flutter PRI

Typically regular and constant for conducted beats

Atrial flutter QRS

< 0.12 seconds

Atrial flutter etiology

May have no apparent cause, caffeine, tobacco, alcohol use, increased sympathetic tone, electrolyte imbalance, hypoxia, digitalis toxicity, cardiovascular disease

Supraventricular tachycardia rate

150–250 bpm

Supraventricular tachycardia rhythm

Regular

Supraventricular tachycardia P-wave

May vary based on underlying rhythm, may not be clearly identifiable due to rate

Supraventricular tachycardia PRI

If identifiable, shortened or normal

Supraventricular tachycardia QRS

< 0.12 seconds

Supraventricular tachycardia etiology

May occur at any age, common in young adults, more common in women than men, stress, overexertion, caffeine, tobacco, illicit drugs, Wolff-Parkinson-White

Supraventricular tachycardia clinical significance

Decreased cardiac output, progression to cardiac arrest, altered mental status

Atrial tachycardia rate

100–250 bpm

Atrial tachycardia rhythm

Regular or irregular

Atrial tachycardia P-wave

Upright and uniform, one before every QRS, morphology changes

Atrial tachycardia PRI

0.12–0.20 seconds or may vary

Atrial tachycardia QRS

< 0.12 seconds

Multifocal atrial tachycardia rate

100–250 bpm

Multifocal atrial tachycardia rhythm

Irregularly irregular

Multifocal atrial tachycardia P-wave

Morphology changes, upright, uniform, not uniform, notched appearance

Multifocal atrial tachycardia PRI

Varies/chaotic

Multifocal atrial tachycardia QRS

< 0.12 seconds

Wandering atrial pacemaker rate

60–100 bpm

Wandering atrial pacemaker rhythm

Regular or irregular

Wandering atrial pacemaker P-wave

Morphology changes beat-to-beat, may be notched, inverted, absent, upright, or rounded

Wandering atrial pacemaker PRI

Varies

Wandering atrial pacemaker QRS

< 0.12 seconds

Wandering atrial pacemaker etiology

Type of sinus dysrhythmia, generally caused by increased vagal tone, associated with underlying heart disease or digitalis toxicity, may be normal in young adults

Wandering atrial pacemaker clinical significance

No detrimental effects, may be precursor to atrial fibrillation

Premature atrial complex rate

Dependent on underlying rhythm

Premature atrial complex rhythm

Underlying rhythm regular, overall irregular due to ectopic beats

Premature atrial complex P-wave

Differs in morphology from underlying rhythm P-wave

Premature atrial complex PRI

Typically normal, but different from underlying rhythm

Premature atrial complex QRS

< 0.12 seconds

Premature atrial complex etiology

May have no apparent cause, caffeine, tobacco, alcohol use, increased sympathetic tone, electrolyte imbalance, hypoxia, digitalis toxicity, cardiovascular disease