A method of predicting onset of electromechanical dissociation in a heart ofa subject is disclosed. The method comprises: extracting from the compositeinput signal an electrocardiac signal and determining electrical activityof the heart based on the electrocardiac signal; extracting from the compositeinput signal a radiofrequency signal and determining blood flow measure basedon the radiofrequency signal; and if the blood flow measure is below a predeterminedthreshold and the electrical activity is above a predetermined threshold, thenpredicting the onset of electromechanical dissociation.