Devices, systems and methods for controlling (inhibiting or enabling) the delivery of electrotherapeutic signals to a heart using sensing of local and/or global ECG signals to detect ventricular arrhythmia or indication of possible ventricular arrhythmia in the heart. The devices, systems and methods process the sensed signals and are capable of delivering electroptherapeutic signals to the heart in the presence of a supra-ventricular arrhythmia such as atrial fibrillation and atrial flutter, while inhibiting the delivering electroptherapeutic signals in the presence of PVCs and/or extopic beats, and/or ventricular arrhythmia. The electrotherapeutic signals may include, among others, pacing signals and cardiac contractility modulating signals.
