Schematic of normal pulmonary venous flow velocity

Pulmonary venous velocity time integrals in systole (VTIs) and diastole (VTId) are determined by planimetry. The VTIs consists of 2 peaks due to early and late systolic atrial filling; the VTId contains a short pulmonary venous flow reversal after atrial contraction. A predominantly negative VTIs (VTIs <0) translates into VTIs/VTId <0, compatible with significant mitral regurgitation.