METHOD AND SYSTEM TO CORRECT CONTRACTILITY BASED ON NON-HEART FAILURE FACTORS

摘要

A method is provided for trending heart failure based on heart contractility information comprises measuring cardiogenic impedance (CI) measurements along at least a first vector through a heart over a period of time. The method determines contractility estimates from the CI measurements, the contractility estimates relating to contractility of the heart. The method further obtains physiologic and/or surrogate signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. The method identifies correction factors based on the physiologic and/or surrogate signals and applies the correction factors to the contractility estimates to produce contractility trend values over the period of time. A system is provided for trending heart failure based on heart contractility information which comprises inputs to receive cardiogenic impedance (CI) measurements taken along at least a first vector through a heart over a period of time. The system includes a contractility module to determine contractility estimates from the CI measurements, the contractility estimates relating to contractility of the heart and a collection module to receive physiologic and/or surrogate signals representing estimates for or direct measurements of at least one of cardiac volume and pressure of the heart when the CI measurements were obtained. A factor module is also provided to identify correction factors based on the physiologic and/or surrogate signals and a correction module to apply the correction factors to the contractility estimates to produce contractility trend values over the period of time.