A new tool for estimating left ventricular ejection fraction derived from wall motion score index.

Area of Science:

• Cardiology
• Medical Imaging
• Diagnostic Techniques

Background:

• Left ventricular ejection fraction (LVEF) is crucial for assessing cardiac function.
• Radionuclide angiography (RNA) and biplane Simpson echocardiography are established LVEF assessment methods.
• A novel approach for LVEF estimation using regional wall motion analysis was explored.

Purpose of the Study:

• To develop a straightforward method for estimating LVEF using the wall motion score index (WMSI).
• To validate this WMSI method with transthoracic echocardiography (TTE).

Main Methods:

• Transthoracic echocardiography (TTE) and radionuclide angiography (RNA) were performed on 243 patients with abnormal left ventricular (LV) contractility.
• A 16-segment model was used to calculate the WMSI.
• A regression equation correlating WMSI with RNA LVEF was derived and validated in separate patient groups, including subgroups with atrial fibrillation, dyskinesia, and aneurysm.

Main Results:

• The WMSI-derived LVEF showed strong correlation with RNA LVEF (r=0.82 in the initial 150 patients, r=0.86 in the validation group of 93 patients).
• High correlations were maintained across subgroups: atrial fibrillation (r=0.87), dyskinesia (r=0.87), and aneurysm (r=0.80).
• Correlation improved to r=0.91 in patients without these specific conditions and was comparable to the biplane Simpson method (r=0.82).

Conclusions:

• LVEF assessment using a simple mathematical model based on WMSI is feasible and practical for routine TTE.
• This WMSI method demonstrates excellent correlation with established techniques like biplane Simpson and RNA.
• The WMSI approach offers a valuable, easy-to-use tool for LVEF estimation in clinical practice.