Methods of treating acute heart failure in a patient in need thereof. Methods include inserting a therapy delivery device into a pulmonary artery of the patient and applying a therapy signal to autonomic cardiopulmonary fibers surrounding the pulmonary artery. The therapy signal affects heart contractility more than heart rate. Specifically, the application of the therapy signal increases heart contractility and treats the acute heart failure in the patient. The therapy signal can include electrical or chemical modulation.
