New non‐invasive approach to detect cardiac contractility using the first sound of phonocardiogram

摘要

During surgery, a non‐invasive and easy‐to‐use method is required for evaluating left ventricular status. The systolic time interval, including pre‐ejection period (PEP), of left ventricle has been known to be correlated with cardiac contractility. In this study, we focused on the non‐invasive time interval from the Q wave of an electrocardiogram to the third component in the first heart sound (QS ‐3rd) and evaluated the correlation between PEP and peak differentiated left ventricular pressure (LV dp/dt).