Evaluation of a noninvasive system for determining left ventricular filling pressure

Background: Measurement of left ventricular filling pressure (LVFP) provides an accurate assessment of left ventricular failure. Clinical and radiographic methods of estimating LVFP are unreliable. The noninvasive method of analyzing the decline in the arterial pressure during the strain phase of the Valsalva maneuver may be used to directly measure LVFP. Objective: To examine the relationship and the level of accuracy of a noninvasive system (VeriCor) in directly determining left ventricular end diastolic pressure (LVEDP) using simultaneously recorded VeriCor and LVEDP measurements obtained during left heart catheterization. Methods: During elective right and left heart catheterization, LVFP was assessed by measuring pulmonary capillary wedge pressure (PCWP) and LVEDP in 57 patients followed immediately by a Valsalva maneuver using the VeriCor assembly to estimate these pressures non-invasively. Results: VeriCor measurements had a significant correlation with the catheter-measured LVEDP (r=0.86), comparable to the correlation of the catheter-measured PCWP with LVEDP (r=0.81). The predictive accuracy of VeriCor for LVEDP, however, appeared to be superior to that of catheter-measured PCWP for LVEDP: 84% of VeriCor measurements compared with only 41% of PCWP measurements were within 4 mm Hg of catheter-measured LVEDP, and 93% of VeriCor measurements compared with only 67% of PCWP measurements were within 6 mm Hg of catheter-measured LVEDP. Conclusion: VeriCor is a reliable noninvasive tool for measuring LVFP.