Left Ventricular Apical Long-Axis Length and Ejection Fraction: A Proof-of-Concept Analysis

Area of Science:

• Cardiology
• Echocardiography
• Medical Imaging Analysis

Background:

• Accurate left ventricular ejection fraction (LVEF) estimation is crucial for cardiac diagnosis, prognosis, and management.
• The standard biplane Simpson method for LVEF calculation has limitations, including image quality dependence and subjective interpretation.
• Simpler methods for LVEF estimation are needed, especially in resource-limited settings.

Purpose of the Study:

• To evaluate the reliability of LVEF estimation using simple apical four-chamber views.
• To compare LVEF derived from simple apical views with the standard biplane Simpson method.
• To determine if longitudinal apical left ventricular (LV) length measurements can serve as a surrogate for LVEF.

Main Methods:

• Retrospective analysis of 260 echocardiographic studies.
• Comparison of LVEF calculated by Simpson's biplane method with longitudinal apical LV length measurements (systole and diastole).
• Statistical analyses including regression and receiver operating characteristic (ROC) curves.

Main Results:

• Significant differences in longitudinal apical LV length measurements were observed between normal and reduced LVEF groups.
• Delta changes in LV length (>14 cm) demonstrated high sensitivity (94.2%) and specificity (95.7%) for identifying normal LVEF.
• ROC analysis indicated end-systolic lengths ≤7.3 cm accurately predict normal LVEF.

Conclusions:

• Simple longitudinal apical LV length measurements are a reliable surrogate for LVEF.
• This method offers a rapid, bedside alternative to the biplane Simpson method.
• Streamlined LVEF estimation is possible, particularly in time-sensitive clinical scenarios.