From the Guidelines
The presence of a rightward axis on an EKG is a significant finding that warrants further cardiac evaluation to determine the underlying cause, as it can be associated with various conditions such as right ventricular hypertrophy, pulmonary embolism, and congenital heart defects. A normal cardiac axis typically ranges from -30° to +90°, while a right axis deviation is defined as an axis greater than +90°. This finding can be identified by examining leads I and aVF on the EKG; when lead I shows a negative deflection and aVF shows a positive deflection, a right axis deviation is present. According to the American Heart Association electrocardiography and arrhythmias committee, council on clinical cardiology 1, right ventricular hypertrophy (RVH) causes 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.
Some common causes of rightward axis deviation include:
- Right ventricular hypertrophy
- Lateral wall myocardial infarction
- Left posterior fascicular block
- Chronic lung disease
- Pulmonary embolism
- Certain congenital heart defects like atrial septal defect
The finding of a rightward axis deviation on an EKG does not require specific treatment, but it is essential to identify and address the underlying cause. The appropriate management depends entirely on identifying what's causing the rightward axis deviation. As stated in the guidelines for electrocardiography by the American College of Cardiology/American Heart Association task force on assessment of diagnostic and therapeutic cardiovascular procedures 1, a baseline ECG in patients with known heart disease or dysfunction gives useful information regarding the presence or absence of arrhythmias, conduction defects, chamber enlargement, myocardial hypertrophy, myocardial ischemia, myocardial necrosis, pericardial inflammation, and electrolyte disturbance.
Further cardiac evaluation, including echocardiography, is necessary to determine the specific etiology of the rightward axis deviation. The electrocardiogram (ECG) is a fundamental tool of clinical practice, and its interpretation may lead to the recognition of electrolyte abnormalities, particularly of serum potassium and calcium, and permit the detection of some forms of genetically mediated electrical or structural cardiac abnormalities, as mentioned in the recommendations for the standardization and interpretation of the electrocardiogram by the American Heart Association electrocardiography and arrhythmias committee, council on clinical cardiology 1.
From the Research
Rightward Axis on EKG
- The provided study 2 does not directly discuss the rightward axis on an EKG.
- The study focuses on a case of coronary artery disease (CAD) with unremarkable ECG and cardiac enzyme results, highlighting the importance of clinical suspicion in diagnosis.
- It mentions the use of ECG in the initial assessment of the patient, but does not provide information on the axis of the EKG.
- There is no mention of the rightward axis on EKG in the study, suggesting that it may not be relevant to the case presented.
- The study emphasizes the importance of further cardiac imaging, such as cardiac computed tomography angiography (CTCA), in diagnosing CAD, especially when initial investigations are normal.