Echocardiography and 6-minute walk test in left ventricular systolic dysfunction

Area of Science:

• Cardiology
• Clinical Physiology
• Diagnostic Imaging

Background:

• Chronic heart failure (CHF) represents a significant global cardiovascular health burden.
• Left ventricular systolic dysfunction is a common and serious complication of CHF.

Purpose of the Study:

• To prospectively evaluate the correlation between the 6-minute walk test (6-MWT) and echocardiographic parameters in stable CHF patients with left ventricular systolic dysfunction.
• To identify clinical factors influencing functional capacity as measured by the 6-MWT.

Main Methods:

• Prospective study of 52 patients with CHF (ischemic heart disease or idiopathic cardiomyopathy) and left ventricular systolic dysfunction (ejection fraction ≤0.45).
• Patients were in stable NYHA class II or III heart failure.
• Echocardiography (including Doppler) and 6-MWT were performed concurrently.

Main Results:

• The 6-MWT showed significant correlations with end-systolic diameter (r=-0.46), shortening fraction (r=0.52), and ejection fraction (r=0.5).
• Correlations were also found with myocardial performance index (MPI) (r=-0.39), tricuspid E/A ratio (r=-0.333), pulmonary acceleration time (r=0.328), and lateral long axis amplitude (r=0.283).
• Independent predictors of 6-MWT performance included age, restrictive transmitral filling pattern, and left ventricular end-systolic dimension.

Conclusions:

• The 6-MWT is a valuable clinical tool for assessing functional capacity in patients with left ventricular systolic dysfunction.
• The 6-MWT results significantly correlate with global left ventricular systolic function parameters and MPI.
• Age, restrictive transmitral filling, and left ventricular end-systolic dimension are independently associated with functional capacity in this patient group.