1. A system, comprising: three or more ECG leads configured to receive an ECG signal; and a first computing device comprising a processor coupled to a memory, the processor and the memory configured to perform operations comprising: generating at least two orthogonal ECG vectors based on the ECG signal of a patient, processing the at least two orthogonal ECG vectors to determine a loop trajectory of at least a portion of the ECG signal, identifying a trajectory bifurcation by comparing the loop trajectory to a control loop trajectory for at least three consecutive cardiac cycles of a plurality of cardiac cycles, determining a variation of the trajectory bifurcation over time, the determination based on an analysis of the trajectory bifurcation of the at least three consecutive cardiac cycles, displaying an indicator of a cardiac event based on the variation of the trajectory bifurcation, and delivering a treatment to the patient based on the indicator of the cardiac event.