Short-term variability in cardiac electrical activity to trigger external actions to reduce arrhythmias

A method comprising:

• sensing, by sensing circuitry of a medical system, cardiac activity of a patient;
• receiving, by processing circuitry of the medical system, an indication of the cardiac activity of the patient;
• based on the sensed cardiac activity, detecting, by the processing circuitry, that the sensed cardiac activity includes precursor to a ventricular tachyarrhythmia;
• and
• responsive to detecting the precursor to the ventricular tachyarrhythmia, causing, by the processing circuitry, delivery of a non-shock therapy to inhibit an onset of the ventricular tachyarrhythmia.

A non-transitory computer-readable storage medium comprising instructions that, when executed, cause processing circuitry of a computing device to:

• receive an indication of cardiac activity of a patient from sensing circuitry of a medical system, wherein:
• the sensing circuitry is configured to sense cardiac activity of the patient, and
• the computing device is a component of the medical system;
• based on the sensed cardiac activity, detect a precursor to a ventricular tachyarrhythmia;
• and
• responsive to detecting the precursor to the ventricular tachyarrhythmia, deliver a non-shock therapy to inhibit an onset of the ventricular tachyarrhythmia.