What is the justification for ordering a 2-dimensional (2D) echocardiogram (echo) in a patient with exertional dyspnea and impaired functional capacity, as indicated by a six-minute walk test?

From the Guidelines

I am ordering a 2D echocardiogram for this patient with exertional dyspnea and poor functional capacity on the six-minute walk test to evaluate for underlying cardiac causes of these symptoms. The echocardiogram will provide crucial information about cardiac structure and function, including assessment of left and right ventricular function, valvular abnormalities, wall motion, and estimation of pulmonary pressures. This is particularly important as exertional dyspnea can result from various cardiac conditions such as heart failure with reduced or preserved ejection fraction, valvular heart disease, or pulmonary hypertension. According to the guidelines released by the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) in 2014 1, two-dimensional echocardiography with Doppler should be performed during the initial evaluation to assess ventricular function, size, wall thickness, wall motion, and valve function. The six-minute walk test has already established functional limitation, suggesting a potentially significant underlying condition. Key points to consider when interpreting the echocardiogram results include:

• Assessment of left ventricular ejection fraction to diagnose heart failure with reduced ejection fraction
• Evaluation of left ventricular hypertrophy and diastolic dysfunction to diagnose heart failure with preserved ejection fraction
• Detection of valvular abnormalities such as stenosis or regurgitation
• Estimation of pulmonary pressures to diagnose pulmonary hypertension The echocardiogram is a non-invasive, radiation-free diagnostic tool that will help determine if cardiac dysfunction is contributing to the patient's symptoms, which is essential for developing an appropriate treatment plan. If cardiac abnormalities are identified, specific therapies such as ACE inhibitors, beta-blockers, diuretics, or valve interventions may be indicated depending on the findings, as suggested by the ACCF and AHA guidelines 1.

From the Research

Justification for Ordering a 2D Echo

When a patient presents with exertional dyspnea and a six-minute walk test indicates long functional capacity, ordering a 2D echo can be justified based on the following points:

• Exertional dyspnea is a common complaint in patients with heart failure with preserved ejection fraction (HFpEF) and chronic obstructive pulmonary disease (COPD) 2.
• Stress echocardiography can help detect diastolic dysfunction, which is a major potential etiology for dyspnea 3.
• Diastolic stress echocardiography can facilitate the attribution of exertional dyspnea to cardiac and non-cardiac disease, and improve the diagnosis of HFpEF or diastolic heart failure 4.
• The six-minute walk test can induce dynamic lung hyperinflation (DH) in patients with COPD, which can be a predictor of dyspnea 5.
• An expanded protocol for stress echocardiography with comprehensive evaluation of clinical and echocardiographic indexes can provide diagnostic capabilities in differential diagnosis of dyspnea 6.

Key Findings

• Studies have shown that stress-induced diastolic dysfunction is prevalent in non-severe COPD patients with exertional dyspnea 2.
• Exercise stress echocardiography (ESE) and cardiopulmonary exercise testing (CPET) can be useful for the early detection and proper management of masked HFpEF in this population 2.
• Diastolic stress exercise echocardiography can improve the sensitivity of the test in patients with dyspnea and provide sufficient data to integrate diastolic exercise test into clinical practice 4.
• The expanded stress-EchoCG protocol with exercise can obtain information about the nature of dyspnea for most patients with shortness of breath of a non-ischemic origin 6.

Diagnostic Considerations

• Ordering a 2D echo can help identify potential cardiovascular etiologies of dyspnea, such as diastolic dysfunction, myocardial ischemia, and valvular heart disease 3.
• The test can also provide information about the patient's cardiac function and structure, which can be useful in determining the cause of exertional dyspnea.
• The results of the 2D echo can be used in conjunction with other diagnostic tests, such as the six-minute walk test and CPET, to provide a comprehensive evaluation of the patient's condition.