From the Guidelines
Left axis deviation (LAD) and poor R wave progression (PRWP) on an EKG are significant findings that may indicate underlying cardiac pathology, particularly left ventricular hypertrophy, left anterior fascicular block, or inferior myocardial infarction, and warrant further cardiac evaluation. These findings can be associated with various conditions, including coronary artery disease, cardiomyopathy, and congenital heart disease. According to the most recent guidelines, the presence of LAD and PRWP on an EKG should be interpreted in conjunction with the patient's clinical presentation, including symptoms, medical history, and other EKG abnormalities present 1. The definition of left axis deviation is an electrical axis more negative than -30 degrees, and poor R wave progression is characterized by R waves that fail to increase appropriately in amplitude across precordial leads V1-V6. Some key points to consider when evaluating these findings include:
- The presence of two or more borderline ECG findings may warrant additional investigation until further data become available 1
- The prognostic information contained within the ECG pattern remains an independent predictor of death even after adjustment for clinical findings and cardiac biomarker measurements 1
- Serial ECG tracings or continuous ST-segment monitoring can provide important prognostic information and may alter therapy 1
- A completely normal ECG in a patient with chest pain does not exclude the possibility of acute coronary syndrome (ACS), and further evaluation is necessary to determine the underlying cause of symptoms 1. In clinical practice, the presence of LAD and PRWP on an EKG should prompt further evaluation, including echocardiography, stress testing, or cardiac catheterization, depending on the clinical context and patient risk factors.
From the Research
Left Axis Deviation and Poor R Wave Progression on EKG
- Left axis deviation is a condition where the electrical axis of the heart is deviated to the left, which can be an indicator of various cardiac conditions, including left ventricular hypertrophy and coronary artery disease 2.
- Poor R wave progression is a common ECG finding that can be caused by several factors, including anterior myocardial infarction, left ventricular hypertrophy, right ventricular hypertrophy, and a variant of normal with diminished anterior forces 3, 4.
- Studies have shown that poor R wave progression is associated with adverse prognosis, including sudden cardiac death, cardiac death, and all-cause mortality, particularly in subjects with coronary artery disease 5.
- Left axis deviation and poor R wave progression can be indicative of reduced left ventricular ejection fraction (LVEF) in patients with suspected acute coronary syndrome, with poor R wave progression in precordial leads with dominant QS pattern in V3 being a simple visual marker for impaired cardiac function 6.
- The combination of left axis deviation and poor R wave progression can be associated with combined diastolic-systolic hypertension and signs of myocardial ischemia, highlighting the importance of considering these ECG findings in the context of overall cardiac health 2.