A patient monitor comprising: an electrocardiograph (14, 20) arranged to monitor an electrocardiographic signal of a patient; a secondary physiological signal monitor (16, 20) arranged to monitor a second physiological signal of the patient concurrently with the electrocardiograph monitoring the electrocardiographic signal of the patient; an alarm condition detector (42, 44) configured to detect an asystole alarm condition based on the electrocardiographic signal of the patient; an alarm condition validator (52, 54, 56) configured to validate the asystole alarm condition based on pulse regularity of a pulsatile component of the concurrently monitored second physiological signal of the patient; and an alarm indicator (24, 26, 58) configured to generate a human-perceptible alarm conditional upon both the alarm condition detector detecting an asystole alarm condition and the alarm condition validator validating the asystole alarm condition, characterized in that the alarm condition validator (52, 54, 56) is configured to (i) compute a pulse regularity index,, quantifying pulse regularity of the pulsatile component of the monitored second physiological signal based on a set of N+1 pulses including (a) a current pulse of the pulsatile component of the monitored second physiological signal and (b) N immediately preceding pulses of the pulsatile component of the monitored second physiological signal, where the current pulse is the pulse of the pulsatile component of the monitored second physiological signal just before, at, or just after a detection of an asystole alarm condition and where N is a positive integer greater than or equal to two, wherein the alarm condition validator (52, 54, 56) is further configured to define one or more pulses of the set of N+1 pulses as a forced pulse detection conditional upon the pulsatile component of the monitored second physiological signal having no pulses in a preselected time interval; and (ii) validate the asystole alarm condition based on the PRI satisfying a validation criterion (54, 56). an electrocardiograph (14, 20) arranged to monitor an electrocardiographic signal of a patient; a secondary physiological signal monitor (16, 20) arranged to monitor a second physiological signal of the patient concurrently with the electrocardiograph monitoring the electrocardiographic signal of the patient; an alarm condition detector (42, 44) configured to detect an asystole alarm condition based on the electrocardiographic signal of the patient; an alarm condition validator (52, 54, 56) configured to validate the asystole alarm condition based on pulse regularity of a pulsatile component of the concurrently monitored second physiological signal of the patient; and an alarm indicator (24, 26, 58) configured to generate a human-perceptible alarm conditional upon both the alarm condition detector detecting an asystole alarm condition and the alarm condition validator validating the asystole alarm condition, characterized in that the alarm condition validator (52, 54, 56) is configured to (i) compute a pulse regularity index,, quantifying pulse regularity of the pulsatile component of the monitored second physiological signal based on a set of N+1 pulses including (a) a current pulse of the pulsatile component of the monitored second physiological signal and (b) N immediately preceding pulses of the pulsatile component of the monitored second physiological signal, where the current pulse is the pulse of the pulsatile component of the monitored second physiological signal just before, at, or just after a detection of an asystole alarm condition and where N is a positive integer greater than or equal to two, wherein the alarm condition validator (52, 54, 56) is further configured to define one or more pulses of the set of N+1 pulses as a forced pulse detection conditional upon the pulsatile component of the monitored second physiological signal having no pulses in a preselected time interval; and (ii) validate the asystole alarm condition based on the PRI satisfying a validation criterion (54, 56).