Noninvasive assessment of diastolic intraventricular pressure gradients using color Doppler M-mode echocardiography

Diastolic intraventricular gradients, while previously observed, are now hypothesized to play a critical role in diastolic filling and function. However, the clinical ability to monitor intraventricular pressure gradients is not normally possible. Doppler echocardiographic M-mode analysis may provide a noninvasive estimate of this important information. The Euler equation, which describes the pressure-velocity relationship along an inflow streamline, is used to compute the diastolic pressure gradient within the ventricle. In a novel experimental setup, the invasive pressures at multiple locations within the ventricular chamber are acquired simultaneously with noninvasive color Doppler M-mode images providing spatiotemporal velocity distributions during diastolic filling. Techniques have been developed to calculate pressure gradients using digitally processed spatiotemporal velocity distributions obtained from the color Doppler M-mode image. These results have been compared with the direct invasive pressure measurements.