RESpiration deTection From Implanted Cardiac Devices in Subjects With Heart Failure (REST-HF)

Inclusion Criteria: * Subject must have heart failure and be undergoing implant of a new or replacement/upgrade Medtronic dual-chamber Implantable Cardioverter Defibrillator or Cardiac Resynchronization Therapy Defibrillator device for approved indications; * Subject must be implanted with an right ventricle lead that supports bipolar pacing and sensing (i.e. a true bipolar defibrillation lead); * Subject must receive a light conscious sedation or no sedation where breathing maneuvers can be performed and evaluated during the implant; * Subject must be willing to provide Informed Consent for their participation in the study; * Subject must be ≥ 18 years of age. Exclusion Criteria: * Subjects who are unable or unwilling to voluntarily participate in any visit required by the study and to provide consent; * Subject has congenital heart disease; * Subject has a tachyarrhythmia (atrial and/or ventricular) at the time of enrollment and a cardioversion will not be attempted prior to the research procedure; * Subject has unstable coronary artery disease; * Subject requires cardiac pacing at rest for rate support; * Subject presents any concomitant conditions which in the opinion of the investigator would not allow a proper execution of the respiratory exercises as per protocol; * Subject presents any concomitant condition which in the opinion of the investigator would not allow a safe participation in the study; * Subject is pregnant or breast feeding; * Subject is legally incompetent; * Subject is enrolled in a concurrent study that may confound the results of this study without documented pre-approval from Medtronic study manager.