What is the clinical significance of poor R wave progression on electrocardiogram (ECG) in patients presenting with chest pain?

From the Guidelines

Poor R wave progression on an EKG in a patient with chest pain is a concerning finding that may indicate an anterior myocardial infarction (heart attack) and requires immediate medical attention. This pattern appears as a failure of the R waves to increase in amplitude across the precordial leads (V1-V6) as they normally should. When seen in the context of chest pain, it could represent ongoing damage to the anterior wall of the left ventricle due to coronary artery occlusion, most commonly the left anterior descending artery.

Key Considerations

• The ECG is an integral part of the diagnostic work-up of patients with suspected MI and should be acquired and interpreted promptly 1.
• Dynamic changes in the ECG waveforms during acute myocardial ischemic episodes often require acquisition of multiple ECGs, particularly if the ECG at initial presentation is non-diagnostic 1.
• Loss of precordial R wave amplitude is an ECG sign associated with acute myocardial ischemia 1.

Management

• Management includes immediate ECG confirmation, cardiac biomarker testing (troponin levels), administration of aspirin (325 mg chewed), consideration of antiplatelet therapy (such as clopidogrel 300-600 mg loading dose), anticoagulation with heparin, and urgent cardiac catheterization if ST-elevation myocardial infarction is confirmed.
• Clinical correlation with symptoms, cardiac biomarkers, and comparison with previous ECGs is essential for proper diagnosis, as poor R wave progression can also represent old anterior infarction, left ventricular hypertrophy, or normal variant in some individuals.

Underlying Mechanism

• The underlying mechanism involves loss of electrical forces moving toward the anterior chest leads due to myocardial damage, resulting in diminished R wave amplitude in those leads. It is crucial to consider that a completely normal ECG in a patient with chest pain does not exclude the possibility of ACS, and other ECG signs and clinical findings should be taken into account for a comprehensive diagnosis 1.

From the Research

Significance of Poor R Wave Progression on EKG with Chest Pain

• Poor R-wave progression is a common ECG finding that can be suggestive of anterior myocardial infarction (AMI), but it is not diagnostic on its own 2.
• The causes of poor R-wave progression can be categorized into four distinct major causes: AMI, left ventricular hypertrophy, right ventricular hypertrophy, and a variant of normal with diminished anterior forces 2.
• In patients presenting with possible acute coronary syndrome (ACS), electrocardiography should be performed immediately to distinguish between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation ACS (NSTE-ACS) 3.
• Poor R-wave progression can be associated with ACS, and its presence in combination with chest pain should prompt further evaluation and treatment, including the administration of aspirin and nitroglycerin 4, 3, 5.
• The treatment approach for ACS includes drug therapies such as antiplatelet agents, anticoagulants, and statins, as well as reperfusion therapies like percutaneous coronary intervention (PCI) or fibrinolytic therapy 4, 3, 6.

Diagnostic Considerations

• High-sensitivity troponin measurements are the preferred test to evaluate for non-ST-segment elevation myocardial infarction (NSTEMI) 3.
• Electrocardiography can distinguish between STEMI and non-ST-segment elevation ACS, and its findings should be interpreted in the context of the patient's clinical presentation 3.
• Poor R-wave progression can be a significant finding in patients with chest pain, and its interpretation should be guided by standard ECG criteria and clinical relevance 2.

Treatment Implications

• Prehospital administration of aspirin and nitroglycerin by non-physician healthcare professionals may be beneficial for patients with suspected ACS, although the certainty of evidence is very low 5.
• Prompt invasive coronary angiography and percutaneous or surgical revascularization within 24 to 48 hours can reduce mortality in high-risk patients with NSTE-ACS 3.
• The treatment approach for ACS should be individualized based on the patient's clinical presentation, ECG findings, and other diagnostic results 4, 3, 6.