Patent ID: 8718750

Claim:
An implantable heart stimulator that can be connected or is connected to at least one electrode lead for picking up electric potentials corresponding to myocardial contraction, a. the implantable heart stimulator including: i. an evaluation unit that is: (1) adapted to being connected to an electrode lead; and (2) configured to evaluate electric signals corresponding to electric potentials picked up by the electrode lead; and ii. a control unit configured to schedule ventricular stimulation pulses; b. wherein: i. the evaluation unit is configured to: (1) detect an atrial event in a heart from the electric signals corresponding to the electric potentials; and (2) determine a P-wave duration of the atrial event from the electric signals corresponding to the electric potentials; and ii. the control unit is configured to: (1) determine an atrio-ventricular delay on a beat-to-beat basis such that an atrio-ventricular delay for an individual heart cycle depends on the P-wave duration of a same or an immediately preceding heart cycle, wherein: (a) the atrio-ventricular delay is calculated as P-wave duration plus Δ duration; and (b) Δ is a function of an AV nodal recovery time, the AV nodal recovery time being an interval between an end of a previous AV nodal refractory period and a following AV nodal activation time; and (2) schedule a ventricular stimulation pulse to be delivered at the end of the atrio-ventricular delay.