A system, comprising: a right ventricular sensing channel configured to sense a right ventricular intrinsic activation; a left ventricular sensing channel configured to sense a left ventricular intrinsic activation; a right ventricular pacing channel configured to deliver a pacing energy to a right ventricle; a left ventricular pacing channel configured to deliver a pacing energy to a left ventricle; and an implantable or external processor, communicatively coupled to the right and left ventricular sensing and pacing channels, wherein the processor is configured to: determine an earlier activation and a later activation of the right ventricle and the left ventricle intrinsic activations during a first cardiac cycle using information about the sensed right and left ventricular intrinsic activations; trigger a first pacing energy to a ventricle corresponding to the later activation during a second cardiac cycle; characterised in that the processor is further configured to: receive an indication of a first depolarization in a ventricle corresponding to the earlier activation, the first depolarization being evoked in response to the first pacing energy; measure a first interval (β) from a time of the first pacing energy to a time of the first depolarization; and compute a first biventricular pacing interval between left and right ventricular paces, termed a first biventricular offset interval, as a function of the first interval β. a right ventricular sensing channel configured to sense a right ventricular intrinsic activation; a left ventricular sensing channel configured to sense a left ventricular intrinsic activation; a right ventricular pacing channel configured to deliver a pacing energy to a right ventricle; a left ventricular pacing channel configured to deliver a pacing energy to a left ventricle; and an implantable or external processor, communicatively coupled to the right and left ventricular sensing and pacing channels, wherein the processor is configured to: determine an earlier activation and a later activation of the right ventricle and the left ventricle intrinsic activations during a first cardiac cycle using information about the sensed right and left ventricular intrinsic activations; trigger a first pacing energy to a ventricle corresponding to the later activation during a second cardiac cycle; determine an earlier activation and a later activation of the right ventricle and the left ventricle intrinsic activations during a first cardiac cycle using information about the sensed right and left ventricular intrinsic activations; trigger a first pacing energy to a ventricle corresponding to the later activation during a second cardiac cycle; characterised in that the processor is further configured to: receive an indication of a first depolarization in a ventricle corresponding to the earlier activation, the first depolarization being evoked in response to the first pacing energy; measure a first interval (β) from a time of the first pacing energy to a time of the first depolarization; and compute a first biventricular pacing interval between left and right ventricular paces, termed a first biventricular offset interval, as a function of the first interval β. receive an indication of a first depolarization in a ventricle corresponding to the earlier activation, the first depolarization being evoked in response to the first pacing energy; measure a first interval (β) from a time of the first pacing energy to a time of the first depolarization; and compute a first biventricular pacing interval between left and right ventricular paces, termed a first biventricular offset interval, as a function of the first interval β.