CALCULATION OF THE AORTIC-VALVE GRADIENT FROM THE LEFT VENTRICULAR-FEMORAL AND AORTIC-FEMORAL PAIRS OF PRESSURE WAVE-FORMS

Accurate measurement of the transaortic gradient is important in the i nvasive assessment of the significance of aortic stenosis. The mean gr adient obtained from simultaneous left ventricular and aortic pressure recordings is the gold standard, but requires two central catheters, We hypothesized that a gradient calculated by subtracting the aortofem oral from the ventriculofemoral gradient would reproduce the ventricul oaortic gradient. In 24 patients sequential recordings of the aortofem oral, ventriculofemoral, and ventriculoaortic pressures pairs were obt ained. The calculated ventriculoaortic gradient was obtained by subtra cting the aortofemoral gradient from the ventriculofemoral gradient. B oth of these gradients were measured by computer, using a systolic eje ction period between the crossovers of the upslope and downslope of th e left ventricular waveform with the femoral waveform. The ventriculoa ortic gradient calculated using this technique correlated closely with the gradient measured by two central catheters (R = 0.99), This techn ique is accurate and does not require two central catheters, (C) 1998 Wiley-Liss, Inc.