Systems, apparatuses, software, and methods for calculating a pulse deficit value of a subject, such as a subject afflicted with a hemodynamic disorder. The devices and apparatuses described herein can include a monitor, at least one ECG sensor, and at least one pulse sensor, where the at least one ECG sensor and the at least one pulse sensor are connected to the monitor, where the monitor converts data collected from the at least one ECG sensor into a value representing depolarization cycle rate, where the monitor is configured to calculate the pulse deficit value based on a number of measured points in time where a difference between the value representing depolarization cycle rate and the value representing pulsation rate exceeds a threshold value, which threshold value is calculated as a fraction of a total number of measured points in time, and where the threshold value is indicative of unacceptable pulse deficit.
