Implantable Medical Device Enabling a Temporary Reduction of a Protective Interval

Implantable medical device for stimulating a human or animal heart, comprising a processor, a memory unit, a stimulation unit configured to stimulate a human or animal heart, and a detection unit configured to detect an electric signal of the same heart, wherein the detection unit comprises a first electrode for detecting right ventricular electric signals and a second electrode for detecting left ventricular electric signals,

• wherein the memory unit comprises a computer-readable program that causes the processor to perform the following steps when being executed on the processor:
• a) determining if a scheduled left ventricular pacing pulse can be delivered with the second electrode, wherein a delivery of the left ventricular pacing pulse is subject to an expiration of a presettable protective interval that is initiated by a preceding left ventricular pacing pulse delivered with the second electrode, a preceding left ventricular depolarization detected with the second electrode, or a preceding logic event triggered instead of a preceding left ventricular pacing pulse at the same time at which the preceding left ventricular pacing pulse was scheduled to be delivered;
• b) if the left ventricular pacing pulse cannot be delivered, since the presettable protective interval is not yet expired, reducing a following presettable protective interval such that it elapses before a respective subsequent left ventricular pacing pulse is scheduled.