From the Guidelines
Axis changes on an EKG can indicate various cardiac conditions or abnormalities, and it is crucial to interpret these changes in the context of the patient's clinical presentation, as some axis deviations may be normal variants in certain individuals. The cardiac axis refers to the overall direction of electrical activity in the heart, and deviations from normal can suggest specific problems. According to the American Heart Association electrocardiography and arrhythmias committee 1, left axis deviation (beyond -30 degrees) may indicate left anterior fascicular block, left ventricular hypertrophy, or inferior myocardial infarction. Right axis deviation (beyond +90 degrees) can suggest right ventricular hypertrophy, right bundle branch block, left posterior fascicular block, or pulmonary conditions like pulmonary embolism or chronic lung disease.
Some key points to consider when interpreting axis changes on an EKG include:
- Left axis deviation is considered to be beyond -30 degrees, with moderate left-axis deviation between -30° and -45°, and marked left-axis deviation from -45° to -90° 1
- Right axis deviation is considered to be beyond +90 degrees, with moderate right-axis deviation between +90° and +120°, and marked right-axis deviation between +120° and +180° 1
- Extreme axis deviation (beyond -90 or +180 degrees) often indicates ventricular rhythms or severe conduction abnormalities
- Axis changes can also occur with electrolyte disturbances, medication effects, or improper lead placement during the EKG
- The significance of axis changes should be interpreted in the context of the patient's clinical presentation, as some axis deviations may be normal variants in certain individuals
It's also important to note that the evaluation and diagnosis of chest pain should be guided by electrocardiographic-directed management, as outlined in the 2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR guideline for the evaluation and diagnosis of chest pain 1. When an axis change is detected, it's essential to compare with previous EKGs when available to determine if this represents an acute change or a chronic finding. Additionally, right ventricular hypertrophy can cause a displacement of the QRS vector toward the right and anteriorly, and often causes a delay in the R-wave peak in right precordial leads, as noted in the AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V 1.
From the Research
Axis Change on EKG
- Axis change on an EKG can refer to a shift in the direction of the electrical axis of the heart, which can be an indicator of various cardiac conditions.
- However, the provided studies do not directly address the topic of axis change on EKG, as they primarily focus on the effects of beta-blockers and ACE inhibitors on cardiovascular diseases, myocardial infarction, and heart failure 2, 3, 4, 5, 6.
- There is no direct evidence in the provided studies to support a specific interpretation of axis change on EKG, and further research would be needed to fully understand its implications.
- The studies do discuss the use of EKGs in diagnosing and monitoring cardiac conditions, but they do not provide information on the specific topic of axis change 2, 3, 4, 5, 6.
Related Cardiac Conditions
- The provided studies discuss various cardiac conditions, including myocardial infarction, heart failure, and ventricular tachyarrhythmia, which can be related to changes in the electrical axis of the heart 2, 3, 4, 5, 6.
- Beta-blockers and ACE inhibitors are commonly used to treat these conditions, and their effects on the heart's electrical activity can be monitored using EKGs 2, 3, 4, 5, 6.
- However, the relationship between axis change on EKG and these cardiac conditions is not explicitly addressed in the provided studies.