What does R (rhythm) wave progression indicate in electrocardiography (ECG)?

From the Guidelines

R wave progression indicates the normal pattern of increasing R wave amplitude as you move from right to left across the precordial leads (V1 to V6) on an electrocardiogram (ECG), showing small R waves in V1-V2 that gradually increase in size through V5, with the tallest R waves typically seen in V4-V5 before slightly decreasing in V6, as described in the 2019 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1. This pattern is essential for proper electrical activation of the ventricles, with the electrical forces initially directed rightward and posteriorly (small R waves in V1-V2) and then moving leftward and anteriorly (larger R waves in V4-V6) as the left ventricle depolarizes. Some key points to consider when evaluating R wave progression include:

• The presence of small R waves in V1-V2 that gradually increase in size through V5
• The tallest R waves typically seen in V4-V5 before slightly decreasing in V6
• The importance of clinical correlation for definitive diagnosis of potential cardiac conditions Poor R wave progression, where this normal pattern is disrupted, can indicate various cardiac abnormalities, including:
• Anterior myocardial infarction
• Left ventricular hypertrophy
• Right ventricular hypertrophy
• Left bundle branch block
• WPW syndrome It is crucial to assess R wave progression as an essential component of ECG interpretation to identify these potential cardiac conditions, as noted in the 2019 ACC/AHA/HRS guideline on the evaluation and management of patients with bradycardia and cardiac conduction delay 1.

From the Research

R Wave Progression Indication

• R wave progression in the precordial leads is an important indicator of myocardial infarction, particularly anterior myocardial infarction 2, 3.
• Poor R wave progression can be caused by various factors, including:
  • Anterior myocardial infarction (AMI) 2, 3
  • Left ventricular hypertrophy 3
  • Right ventricular hypertrophy 3
  • A variant of normal with diminished anterior forces 3
• A mathematical model can be used to identify patients with anterior infarction among those with poor R wave progression, with a sensitivity of 85% and a specificity of 71% 2.
• The diagnosis of anterior infarction can be established by the presence of fixed thallium-201 perfusion defects in the anterior wall or septum, or both 2.
• R wave progression is also related to other cardiac conditions, such as coronary microvascular dysfunction 4 and conduction disorders in the setting of acute STEMI 5.