Measurement of Cardiac First Phase Ejection Fraction

摘要

Embodiments of the invention provide a method and system for measuring first phase ejection fraction where simultaneous measurement of the systolic pressure during systole of a subject is undertaken at the same time as measurement of the left ventricle volume (LVV). The pressure waveform is then analyzed, for example using automated signal processing techniques, to find a time T1 which corresponds to the point at which the rate of change of systolic pressure during systole begins to reduce. The left ventricle volume at this time T1 is then found from the previous measurements of LVV obtained at the same time as the systolic pressure measurement, and the first phase ejection fraction then calculated in dependence on the LVV at time T1 and the LVV at the start of systole i.e. the end diastolic volume (EDV). In particular embodiments, the first phase ejection fraction is the difference between LVV at EDV and LVV at time T1.