Methods and systems for transvenously accessing the pericardial space via the vascular system and atrial wall, particularly through the superior vena cava and right atrial wall, to deliver a pharmacologic agent, particularly a NO-donor drug, to the heart are disclosed. A proximal connector of an infusion catheter is coupled to an infusion pump, and a distal catheter segment having a distal infusion catheter lumen end opening is disposed in the pericardial space. The implantable infusion pump is operable in conjunction with an implantable ischemia monitor to monitor the ischemic state and trigger delivery or regulate the periodic delivery of the pharmacologic agent to optimally treat ischemia. The patient may operate a patient activator that the patient when feeling ischemia symptoms to transmit a signal that is received by the implantable infusion pump and triggers delivery of a bolus and/or continuous infusion.