What is the significance of an increased Mitral (mitral valve) E/A ratio?

From the Guidelines

An increased mitral E/A ratio (typically >2) is a significant indicator of restrictive left ventricular filling, often associated with diastolic dysfunction, and suggests elevated left atrial pressure and impaired ventricular relaxation. This finding is crucial in assessing the grade of diastolic dysfunction, with an E/A ratio ≥2 indicating grade III diastolic dysfunction, as noted in the guidelines for the evaluation of left ventricular diastolic function by echocardiography 1. The E wave represents early passive filling of the left ventricle, while the A wave represents atrial contraction. When the E/A ratio is elevated, it typically indicates advanced diastolic dysfunction, which can occur in conditions like restrictive cardiomyopathy, constrictive pericarditis, or severe heart failure.

Key points to consider in the interpretation of an increased mitral E/A ratio include:

• The E/A ratio should be interpreted in conjunction with other echocardiographic parameters, such as peak E velocity, mitral deceleration time (DT), and left atrial (LA) maximum volume index, to accurately assess diastolic function 1.
• In patients with an E/A ratio >2, the presence of elevated left atrial pressure is likely, and management should focus on treating the underlying cause, which may include diuretics, ACE inhibitors or ARBs, beta-blockers, and specific treatments for the primary condition.
• It is essential to consider the clinical context, including age, as E/A ratios >2 may be a normal finding in young individuals (<40 years of age) 1.
• Close monitoring of symptoms, fluid status, and follow-up echocardiography is crucial in managing patients with an increased mitral E/A ratio.

In terms of management, the approach should be tailored to the underlying cause of the diastolic dysfunction. For example, in heart failure with preserved ejection fraction, treatment with spironolactone 25mg daily and furosemide 20-40mg daily may be considered, along with close monitoring of symptoms and fluid status 1. The increased E/A ratio reflects rapid early filling due to high left atrial pressure followed by reduced filling during atrial contraction, often indicating a poor prognosis if not addressed promptly.

From the Research

Significance of an Increased Mitral E/A Ratio

• The mitral E/A ratio is a parameter used to assess diastolic function and left ventricular filling pressures 2.
• An increased E/A ratio is associated with elevated left ventricular filling pressures and diastolic dysfunction 3, 2.
• In patients with preserved left ventricular ejection fraction, an increased E/A ratio can be an indicator of heart failure with preserved ejection fraction (HFpEF) 3.
• The E/A ratio can be used in combination with other parameters, such as the E/e' ratio, to assess left ventricular diastolic function and filling pressures 2.
• An increased E/A ratio has been linked to worse structural and functional echocardiographic alterations, including left atrial enlargement and left ventricular hypertrophy 4.

Clinical Implications

• An increased mitral E/A ratio can be a predictor of mortality and cardiovascular events in patients with chronic kidney disease 5.
• The E/A ratio can be used to diagnose elevated left atrial pressure and left ventricular filling pressures, which are common in patients with HFpEF 3.
• Low-grade chronic inflammation has been linked to depressed left atrial compliance and increased mitral E/e' ratio, which can contribute to the development of HFpEF 6.
• The mitral E/A ratio can be used as a non-invasive tool to assess left ventricular diastolic function and filling pressures, which can help guide treatment decisions and monitor disease progression 3, 2.