From the Guidelines
An RSR' pattern on an ECG is a specific waveform in the QRS complex that can be a normal variant in healthy individuals, particularly young adults and athletes, but may indicate pathology in patients with underlying heart disease. The significance of an RSR' pattern varies based on the clinical context and the patient's underlying health, as noted in the 2019 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. This pattern is most commonly seen in right bundle branch block (RBBB) or incomplete RBBB, depending on the QRS duration. Some key points to consider when evaluating an RSR' pattern include:
- The QRS duration, with complete RBBB defined as a QRS duration ≥120 ms and incomplete RBBB defined as a QRS duration between 110 and 119 ms 1
- The presence of other ECG abnormalities, such as sinus node dysfunction or atrioventricular block 1
- The patient's age, symptoms, medical history, and other ECG findings, as these can help determine the clinical significance of the RSR' pattern In asymptomatic individuals without cardiac history, an isolated RSR' pattern typically doesn't require specific treatment or further evaluation. However, in patients with cardiac symptoms, known heart disease, or other concerning ECG findings, further cardiac evaluation may be warranted to determine if there is underlying structural or electrical heart disease, as recommended by the AHA/ACCF/HRS 1. It's also important to note that the appearance of LBBB may change the mean QRS axis in the frontal plane, and the ST and T waves are usually opposite in direction to QRS in complete LBBB 1. Overall, the clinical significance of an RSR' pattern depends on the individual patient's context and underlying health, and should be evaluated in conjunction with other ECG findings and clinical factors.
From the Research
RSR' Pattern on ECG
- The RSR' pattern on an electrocardiogram (ECG) is a phenomenon that can be observed in leads V1-V2, and its significance can vary from benign to life-threatening conditions 2.
- This pattern can be associated with atrial septal defect (ASD) and right ventricular dilation, and its presence can guide the screening and follow-up of patients with isolated secundum ASD 3.
Significance of RSR' Pattern
- The RSR' pattern can be a benign finding in older adults free of clinical cardiovascular disease, with no increased risk of cardiovascular disease or all-cause mortality 4.
- However, in certain cases, the RSR' pattern can be a sign of underlying conditions such as Brugada syndrome or arrhythmogenic right ventricular dysplasia, which can be life-threatening 2.
- The presence of an RSR' pattern can also be used to predict the need for surgical or device intervention in patients with moderate to large ASDs 3.
Patient-Specific Considerations
- In patients with atrial fibrillation, the presence of a bundle branch block pattern, including RSR', can be associated with a higher risk of heart failure events 5.
- In asymptomatic and otherwise healthy individuals, the RSR' pattern can be a normal variant, but it can also be misinterpreted as pathological after certain clinical events such as cardiac arrest or syncope of unknown cause 2.
- The use of high precordial lead ECGs and newly proposed criteria can help identify true Brugada pattern ECGs and distinguish them from benign RSR' patterns 6.