Response to Letter Regarding Article, “Mechanisms of Preejection and Postejection Velocity Spikes in Left Ventricular Myocardium: Interaction Between Wall Deformation and Valve Events”

We thank Drs Sengupta and colleagues for their interest in our work.1 Our aim was to understand what causes the pre- and postejection velocity spikes. The main focus of Sengupta et al is to understand why the spikes sometimes cross the zero line, a phenomenon that they name biphasic spikes , as it denotes both a shortening phase (positive velocity) and a lengthening phase (negative velocity). This is an interesting topic, but it was outside the scope of our study.1 The preejection velocity has a spike shape, ie, an upstroke and a downstroke. The upstroke from zero reflects the start of shortening, which pushes blood toward the valve plane and closes the mitral valve. Mitral valve closure then …