Abstract: For treatment of cardiac tissue of a heart of a patient with therapeutic light using an implantable medical device connectable to at least one medical lead carrying electrodes and at least one fixation element that fixes the lead at a fixation area of the cardiac tissue, therapeutic light is emitted toward the at least one fixation area of cardiac tissue and/or toward a contact area between the at least one electrode and cardiac tissue using an intracorporeal light emitter.

Abstract: A heart stimulator, operable for single-chamber and/or dual-chamber pacing, includes a first unipolar electrical lead placeable in the atrium of a heart, and a second unipolar electrical lead placeable in the ventricle of the heart. In the heart stimulator, a differential detector is connected to each of these unipolar leads and detects a differential signal representative of cardiac activity between the atrial electrode and the ventricular electrode. The differential signal is supplied to decision logic which evaluates each of those outputs including using a morphology analysis, if necessary. Depending on the type of cardiac activity identified as a result of the evaluation, the decision logic supplies a signal to a control unit in the heart stimulator to cause the therapy administered by the heart stimulator to be altered as warranted. The decision logic may also derive a respiration signal from the differential signal, which can also be used to modify the administered therapy.