Detection of mechanical waves in the left ventricle using high frame rate imaging

Abstract

Echocardiography is a key imaging modality to assess cardiac anatomy and function. In the past decade, high frame rate ultrasound imaging has emerged, and has allowed for studies of rapid phenomena that occur in the heart. The investigated phenomena are mechanical waves propagating in cardiac tissue at high velocities. Our goal was to detect properties of these waves useful for non-invasive diagnosis of cardiac diseases currently diagnosed with invasive, time consuming and expensive methods. Regional mechanical activation of the heart was investigated for the purpose of detecting abnormal activation patterns indicating conduction disorders. A method was developed to map the mechanical activation wave occurring after electrical activation, and its feasibility demonstrated in an animal study. Mechanical waves occurring naturally in tissue after mechanical events in the heart were investigated for the purpose of using propagation velocities to separate between healthy and pathological tissue. A method for velocity estimation was developed and its feasibility demonstrated in two studies of human populations. Both methods have been evaluated for clinical scenarios and validated against invasive and non-invasive reference standards. They have the potential of having clinical impact in the diagnosis of several cardiac diseases related to conduction and tissue abnormalities.