Evaluation of left ventricular volumes and ejection fraction with a nonfluoroscopic endoventricular three-dimensional mapping technique

Background: Recently, a novel nonfluoroscopic 3-dimensional electromechanical mapping technique was introduced in the clinical arena. Although initial in vitro and in vivo studies suggested the reliability of the system in volumetric and hemodynamic evaluation of the left ventricle, no validation in human beings has been performed. Methods: A nonfluoroscopic electromechanical mapping (NOGA, Biosense-Webster) procedure was performed in 44 patients. All patients received a contrast left ventriculogram during the same session. Volumetric (end-diastolic [EDV] and end-systolic volumes [ESV]) and hemodynamic (left ventricular ejection fraction [LVEF] and stroke volume) parameters of both systems were compared. Results: Two uncomplicated pericardial effusions occurred with the first-generation mapping catheters. No procedural complications were noted with the new-generation mapping catheters. Significant correlations were found between mapping-derived and ventriculography-based measurements for both ESV (r = 0.67, P < .001) and LVEF (r = 0.78, P < .001). Absolute volumes, however, were only comparable for ESV (46.6 ± 25.3 mL vs 48.8 ± 37.0 mL, respectively; P = .13) but differed greatly for LVEF (35% ± 13% vs 65% ± 19%, respectively; P < .001), EDV (69.1 ± 28.6 mL vs 125.9 ± 53.4 mL, respectively; P < .001) and stroke volume (22.4 ± 9.9 mL vs 77.1 ± 33.7 respirations; P < .001). Moreover, Bland-Altman analysis showed the clinical noninterchangeability between these techniques for the measurement of hemodynamic parameters. Conclusion: Measurement of hemodynamic parameters with nonfluoroscopic mapping of the left ventricle is feasible and safe. The system provides data that strongly correlate but that are in clinical disagreement with angiographic data. Therefore the interchangeability of these techniques may be questioned.