Predicting the Left Ventricular Ejection Fraction Using Bimodal Cardiac Auscultation

Aims: Heart Failure (HF) is a global health challenge that is often associated with reduced left ventricular ejection fraction (EF). Current EF assessments rely on<br/>echocardiography exams performed by specialists. This study explores the feasibility of predicting EF using cardiac intervals derived from synchronous<br/>phonocardiography (PCG) and single-lead electrocardiography (ECG) recorded with a bimodal stethoscope.<br/>Methods: 84 pairs of synchronous PCG and ECG signals were collected from 42 patients. Signal pairs were categorized into three different EF groups: EF &lt;40%, EF 40-49% and EF ≥50%.<br/>Results: Logistic regression revealed that the QS2 interval was a significant predictor of reduced ejection fraction, with p = 0.0186 for EF &lt;/&gt; 40% and p = 0.0090 for EF &lt;/&gt; 50%. QT interval showed no predictive value.<br/>The Kruskal-Wallis test showed significant group differences for QS2 (p=0.008) and S1S2 (p=0.009), but not for QT (p=0.299) or QS1 (p=0.673). Mann-Whitney U-test confirmed that QS2 and S1S2 intervals differed significantly between EF.