What does a rightward axis and borderline Electrocardiogram (EKG) indicate?

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Last updated: May 13, 2025View editorial policy

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From the Guidelines

A rightward axis on an EKG with a "borderline EKG" interpretation is a finding that requires further evaluation to determine its significance, as it can be a normal variant or indicate conditions like right ventricular hypertrophy, right bundle branch block, or pulmonary issues. This finding can be normal in some people, especially those with certain body types or anatomical variations. However, it can also indicate conditions that may affect morbidity, mortality, and quality of life. A rightward axis is defined as an electrical axis greater than +90 degrees 1.

Possible Causes and Implications

The possible causes of a rightward axis on an EKG include:

  • Right ventricular hypertrophy (RVH), which can be caused by conditions such as pulmonary hypertension, congenital heart disease, or chronic obstructive pulmonary disease (COPD) 1
  • Right bundle branch block (RBBB), which can be caused by conditions such as coronary artery disease, cardiomyopathy, or pulmonary embolism 1
  • Pulmonary issues, such as pneumonia, pleurisy, or pneumothorax 1

Diagnostic Approach

If you've received this interpretation, you should follow up with your healthcare provider for further evaluation, which might include additional tests like:

  • Echocardiogram to assess heart structure and function 1
  • Chest X-ray to evaluate lung fields and cardiac silhouette 1
  • Pulmonary function tests to assess lung function 1
  • Right heart catheterization to measure pulmonary artery pressures and assess cardiac function 1

Importance of Further Evaluation

The significance of this finding depends on your symptoms, medical history, and other EKG findings. While not always concerning, it shouldn't be ignored, especially if you're experiencing symptoms like chest pain, shortness of breath, or palpitations. Your doctor will determine if this represents a normal variant for you or requires further investigation. It's essential to prioritize morbidity, mortality, and quality of life when evaluating this finding, and further testing may be necessary to determine the underlying cause and develop an appropriate treatment plan.

From the Research

EKG Findings

  • A rightward axis on an EKG can indicate a variety of conditions, including right ventricular hypertrophy or dilation 2.
  • Borderline EKG findings may suggest a need for further evaluation or monitoring to determine the underlying cause of the abnormality.

Right Ventricular Function

  • Echocardiography is a useful tool for assessing right ventricular function and can provide valuable information on RV size and function 3, 4, 5, 2.
  • Right ventricular dysfunction can be a marker of morbidity and mortality in several clinical situations, including heart failure, pulmonary hypertension, and pulmonary embolism 2.
  • Stress echocardiography and cardiopulmonary exercise testing can be used to evaluate RV functional recovery after pulmonary embolism 6.

Clinical Implications

  • A larger RV diameter can be a marker of poor prognosis in patients with idiopathic pulmonary arterial hypertension 3.
  • Echocardiographic findings of right ventricular strain, such as increased RV:LV size ratio and abnormal septal motion, can suggest a diagnosis of pulmonary embolism 5.
  • RV systolic dysfunction and RV to pulmonary artery uncoupling can be associated with increased ventilatory inefficiency and reduced peak oxygen pulse 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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