Treatment of Right Axis Deviation (RAD)
Right axis deviation is not a disease requiring treatment itself, but rather a sign of an underlying condition that should be identified and treated appropriately.
Understanding Right Axis Deviation
Right axis deviation (RAD) is an electrocardiographic finding defined as a mean QRS axis greater than +90° in adults 1, 2. Normal QRS axis in adults ranges from +30° to +90° 2. The definition varies by age:
- Adults: RAD is >+90° (moderate: +90° to +120°, marked: +120° to +180°) 1
- Children 8-16 years: RAD is >+120° 1
- Children 5-8 years: RAD is >+140° 1
- Children 1-5 years: RAD is >+100° 1
- Neonates: RAD is >+190° 1
Diagnostic Approach to RAD
When RAD is identified on ECG, the following approach should be taken:
Confirm the finding: Ensure proper lead placement and technique 2
Consider age-appropriate interpretation: What appears as RAD in adults may be normal in children 2
Look for associated ECG findings:
- Right ventricular hypertrophy (RVH) patterns
- Right bundle branch block (RBBB)
- qR complex in lead V1
- S1, S2, S3 pattern 1
Identify the underlying cause: RAD is commonly associated with:
Treatment Algorithm
The treatment of RAD follows this algorithm:
1. Pulmonary Hypertension
If RAD is associated with pulmonary hypertension:
- Perform echocardiography to confirm and assess severity 1
- Treat the underlying cause of pulmonary hypertension (e.g., pulmonary arterial hypertension, left heart disease, lung disease) 1
- Consider pulmonary vasodilators for pulmonary arterial hypertension 1
2. Right Ventricular Hypertrophy
If RAD is associated with RVH:
- Identify and treat the underlying cause (e.g., pulmonary hypertension, congenital heart disease) 1
- Monitor for development of right heart failure 1
3. Congenital Heart Disease
If RAD is associated with congenital heart disease:
- Refer to a congenital heart disease specialist for appropriate management 1
- Treatment may include surgical repair or medical management depending on the specific defect 1
4. Left Posterior Fascicular Block
If RAD is due to left posterior fascicular block:
- Evaluate for underlying coronary artery disease 3, 4
- If associated with acute myocardial infarction, provide appropriate coronary revascularization 5, 3
5. Acute Myocardial Infarction with RAD
If RAD occurs during acute myocardial infarction:
- Consider urgent coronary angiography and revascularization 5
- Monitor closely as this may indicate a poor prognosis 5
6. Chronic Lung Disease
If RAD is associated with chronic lung disease:
- Optimize management of the underlying pulmonary condition 1
- Consider oxygen therapy if hypoxemia is present 1
Special Considerations
New-onset RAD: Particularly concerning when it develops acutely, especially with RBBB, as it may indicate severe myocardial ischemia requiring urgent intervention 5
Changing axis deviation: May occur during acute myocardial infarction and requires close monitoring 3, 4
Hereditary RAD: Rare familial pattern that may not require specific treatment if no structural heart disease is present 6
Monitoring and Follow-up
- Serial ECGs to monitor for changes in axis deviation
- Echocardiography to assess right ventricular function and pulmonary pressures
- Regular clinical assessment for symptoms of right heart failure
Pitfalls to Avoid
Don't treat the ECG finding alone: Always identify and treat the underlying cause
Don't miss pulmonary hypertension: ECG has limited sensitivity (73%) for detecting pulmonary hypertension, so consider echocardiography even with minimal symptoms 1
Don't overlook acute coronary syndromes: New-onset RAD during chest pain may indicate severe coronary artery disease requiring urgent intervention 5
Don't ignore RAD in children: Interpret in age-appropriate context, as normal ranges differ significantly 1
Don't attribute RAD to technical errors without confirmation: While lead misplacement can cause apparent RAD, true RAD requires thorough investigation 2