Real time endocardiac volumetry

An algorithm for endocardiac volumetry using the same technical resources as for a non-fluoroscopic guiding system of an ablation catheter is presented. The authors' method is based on the detection of a supplemental monopole or dipole position. It is added to the cardiac natural sources by injecting a low amplitude high frequency current source (and sink). An expanded super elastic basket electrode, containing 64 monopolar recording sites will give 64 coordinates of the endocardiac surface. Volume or blood flow can be further calculated and monitored. A least square method as well as an adequate signal filtering assure noise immunity and small error of the method. Simultaneous cardiac mapping, volumetry and catheter guiding can be done.