Echocardiographic Particle Image Velocimetry in Heart Diseases

Echocardiographic particle image velocimetry (Echo-PIV) is an emerging technique to provide us useful information of the left ventricular (LV) blood flow and vortex in various heart diseases. Vortex flow in vivo is extremely complicated and affected by many factors and also has several roles. Factors affect on LV vortex formation are LV size and geometry, myocardial mechanics, electro-mechanical sequence, hemodynamics, and the mitral valve. Essential roles of vortex are 1) a temporary kinetic energy reservoir, 2) blood flow redirection, 3) closure of the mitral valve, and 4) diastolic filling facilitator. Understanding the LV blood flow and vortex may be useful in many clinical situations for heart diseases such as heart failure, myocardial infarction, and valvular diseases. There is also a report that bi-ventricular pacing optimizes the LV diastolic filling by optimizing the timing of the onset of the diastolic vortex from the mitral valve opening. Understanding of LV blood flow and vortex has a clinical potential for early diagnosis, risk stratification, and treatment of heart diseases.