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)

This pattern is best described as notched R waves. When you see two upward deflections within a single QRS and there isn’t a separate S wave between them, the R wave appears split or bifid—a notch creating a second peak. This reflects asynchronous ventricular activation due to slowed conduction in one pathway, such as a bundle branch delay, which makes the initial R deflection followed by a second, smaller rise. Atrial flutter would show characteristic sawtooth atrial activity, not a double R peak within a QRS. Bundle branch block can produce broad, sometimes notched R waves, but the specific description of two R deflections within one QRS without an intervening S wave is the classic notched (or bifid) R wave pattern. Early depolarization typically refers to J-point or end-of-QRS notching that isn’t described as two R waves inside a single QRS.

This pattern is best described as notched R waves. When you see two upward deflections within a single QRS and there isn’t a separate S wave between them, the R wave appears split or bifid—a notch creating a second peak. This reflects asynchronous ventricular activation due to slowed conduction in one pathway, such as a bundle branch delay, which makes the initial R deflection followed by a second, smaller rise.

Atrial flutter would show characteristic sawtooth atrial activity, not a double R peak within a QRS. Bundle branch block can produce broad, sometimes notched R waves, but the specific description of two R deflections within one QRS without an intervening S wave is the classic notched (or bifid) R wave pattern. Early depolarization typically refers to J-point or end-of-QRS notching that isn’t described as two R waves inside a single QRS.