Velocity of left ventricular wall motion determined by fluoroscopic videodensitometry. A noninvasive method for...

Videodensitometry of the margins of the fluoroscopic image of the left ventricle (LV) was used to evaluate LV wall motion and differentiation of the wall motion signal reflected velocity of LV contraction (dV/dt) during various inotropic interventions in six anesthetized dogs. During these interventions heart rate, afterload and preload were maintained constant. Alterations in dV/dt were similar to changes in simultaneously measured LV peak dP/dt and the quotient of dP/dt and developed LV pressure, two widely accepted parameters of LV contractile state. Wide variations in preload and afterload caused no significant changes in dV/dt. Thus, the current study indicates that fluoroscopic videodensitometry provides a specific and reliable noninvasive method for evaluating LV contractile state.