RSR' Pattern in V1 and V2 on EKG: Significance and Interpretation

Definition and Characteristics

The American College of Cardiology notes that an RSR' pattern in leads V1 and V2 on an electrocardiogram refers to a specific QRS complex morphology consisting of an initial small R wave, followed by an S wave, and then a second R wave (R') 1, 2
The R' or r' deflection is usually wider than the initial R wave according to established criteria from the American College of Cardiology 3, 4
This pattern is one of the hallmark features of right bundle branch block when accompanied by appropriate QRS duration criteria, as indicated by the American College of Cardiology and Circulation 1, 2

The American College of Cardiology and Circulation recommend that QRS duration ≥120 ms in adults, >100 ms in children ages 4-16 years, and >90 ms in children <4 years of age be used as a diagnostic criterion for complete RBBB 2, 4
An RSR', rsR', rSR', or rarely a qR pattern in leads V1 or V2 is also a diagnostic criterion for complete RBBB, according to the American College of Cardiology 1, 3
The American College of Cardiology notes that an S wave of greater duration than R wave or >40 ms in leads I and V6 is another diagnostic criterion for complete RBBB 1, 3
Normal R peak time in leads V5 and V6 but >50 ms in lead V1 is also a diagnostic criterion for complete RBBB, as indicated by the American College of Cardiology 3, 5

The American College of Cardiology recommends that the same QRS morphology criteria as complete RBBB be used for incomplete RBBB, but with a QRS duration between 110-119 ms in adults 1, 3
In children, incomplete RBBB may be diagnosed when the terminal rightward deflection is <40 ms but ≥20 ms, according to the American College of Cardiology 4, 6

The American College of Cardiology notes that in children, an RSR' pattern in V1 and V2 with a normal QRS duration is considered a normal variant 4, 6
The American College of Cardiology recommends that the terms "RSR" and "normal RSR" not be used to describe such patterns due to potential misinterpretation 4

The presence of RSR' with prolonged QRS duration indicates conduction tissue disease affecting the right bundle branch, according to the American College of Cardiology 1, 3
In asymptomatic individuals, especially children, with normal QRS duration, an RSR' pattern is often benign, as noted by the American College of Cardiology 4, 6

The American College of Cardiology notes that in athletes, isolated QRS voltage criteria for right ventricular hypertrophy, including RSR' pattern with normal QRS duration, is part of the normal spectrum of ECG findings and does not require further evaluation 7

The American College of Cardiology states that a normal variant RSR' is present when QRS duration is normal, particularly common in children and athletes, with a normal QRS duration (<110 ms in adults) 7
Right ventricular hypertrophy (RVH) can be associated with an RSR' pattern, as indicated by the American College of Cardiology 8