An atrial rhythm occurs due to abnormal electrical impulses that start in the atria or around the AV Node.

Atrial Fibrillation

• Rate: < 100 bpm (controlled) > 100 bpm (uncontrolled)
• Rhythm: Irregular
• P Waves: Absent or indiscernible
• PR Intervals: Not measurable
• R-R Intervals: Unequal
• QRS Complexes: Normal

Atrial Flutter

• Rate: 250-350 bpm (atrial)
• Rhythm: Regular
• P Waves: Absent and replaced with a “sawtooth” pattern
• PR Intervals: Not measurable
• R-R Intervals: Equal
• QRS Complexes: Normal

Supraventricular Tachycardia

• Rate: > 150 bpm
• Rhythm: Regular
• P Waves: Absent or indiscernible
• PR Intervals: Not measurable
• R-R Intervals: Equal
• QRS Complexes: Normal