Two R waves in the same QRS complex without an intervening S wave produce a pattern technically called RR, but it is commonly described as what?

Two R waves in the same QRS complex without an intervening S wave produce a pattern technically called RR, but it is commonly described as what?

• A. Notched R waves
• B. Atrial flutter
• C. Bundle branch block
• D. Early depolarization

Answer: (A)

Notched R waves describe a second positive bump within the same QRS, giving the R wave a bifid appearance. This happens when two ventricular activation fronts reach the recording lead with a brief separation in time, so you see an R followed by a small R’ without a intervening S. The result is a pattern commonly described as notched (or bifid) R waves, which is the best way to name this morphology. Atrial flutter would show rapid atrial activity with flutter waves rather than a double-peaked R within one QRS. Bundle branch block tends to produce a wide QRS with characteristic waveforms, not simply two R peaks in one complex. Early depolarization refers to distinct J-point changes rather than a double R within the QRS.