What is the meaning of an rSR' pattern in lead V4 (electrocardiogram lead)?

From the Guidelines

The rsR pattern in V4 is indicative of a complete Right Bundle Branch Block (RBBB) as defined by the presence of an rsR', rsR, rSR, or rarely a qR pattern in leads V1 or V2, with the R' or r' deflection usually wider than the initial R wave, according to the 2018 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. This pattern is characterized by a small initial r wave, followed by a deep S wave, and then a prominent R wave in lead V4. The criteria for complete RBBB also include a QRS duration of ≥120 ms, an S wave of greater duration than the R wave or >40 ms in leads I and V6, and a normal R peak time in leads V5 and V6 but >50 ms in lead V1 1. The rsR pattern is significant because it can indicate conditions such as pulmonary hypertension, congenital heart disease, or other disorders causing right-sided heart strain. When evaluating this pattern, it's essential to consider it alongside other ECG criteria and clinical context, including symptoms of right heart failure, shortness of breath, or known lung disease. Key points to consider in the interpretation of the rsR pattern in V4 include:

• The presence of a complete RBBB pattern, as defined by the 2018 ACC/AHA/HRS guideline 1
• The QRS duration and morphology in leads V1 and V2
• The presence of other ECG criteria for right ventricular hypertrophy (RVH), such as right axis deviation
• Clinical context, including symptoms and known medical history It's crucial to note that the rsR pattern can occur in various conditions, and a thorough evaluation of the patient's clinical context and other ECG findings is necessary to determine the underlying cause and appropriate management.

From the Research

rsR Pattern in V4 Meaning

The rsR pattern in lead V4 is a topic of interest in electrocardiography, and several studies have investigated its significance.

• The study 2 discusses the differential diagnosis of the rSr' pattern in leads V1-V2, which may be relevant to understanding the rsR pattern in V4.
• Another study 3 analyzed the RSR' pattern in right chest leads in patients with hypertrophic cardiomyopathy, providing insights into the vectorcardiographic characteristics of this pattern.
• A more recent study 4 investigated the significance of right-sided precordial ECG leads (V3R and V4R) in assessing right ventricular dysfunction, finding that the rsR pattern was not specifically mentioned, but the study did report on the prevalence of qR, rS, and QS patterns in these leads.
• The study 5 found that the RSR' pattern was not associated with an increased risk of cardiovascular disease or all-cause mortality in individuals free of clinical cardiovascular disease.
• Additionally, the study 6 discussed the challenges in diagnosing incomplete right bundle branch block, which may be related to the rsR pattern in V4, highlighting the importance of differentiating this condition from pathological patterns.

Possible Causes and Associations

The rsR pattern in V4 may be associated with various conditions, including:

• Benign nonpathological variants 2
• Hypertrophic cardiomyopathy 3
• Right ventricular dysfunction 4
• Incomplete right bundle branch block 6
• It is essential to consider the clinical context and other ECG findings when interpreting the rsR pattern in V4, as it may not always be a benign condition 6.