Cardiac Rhythm Monitoring After Acute Decompensation for Heart Failure

Inclusion Criteria: * Subject with a history of at least one heart failure (HF) hospitalization (as defined in the European Society of Cardiology or American College of Cardiology/American Heart Association guidelines), emergency department (ED) visit, or urgent office visit necessitating intravenous (IV) diuretic or augmentation of oral diuretic, IV inotropic, or IV vasodilator or other HF parenteral therapy within 15 days prior to device implant * Subject has an implanted Reveal® XT device (less than 15 days post implant); * Ejection Fraction (EF) less than 40 percent * Patient with access to a telephone line * Patient or the patient's caregiver is willing and able to use the Medtronic CareLink® Network Monitor and to perform the required duties at home or has a family member or assistant perform those duties * Age greater than 18 years old * Patient is willing and able to comply with the Clinical Investigation plan and willing to remain available for follow-up visit, through study closure * Patient (or patient's legally authorized representative) is willing and able to sign and date the study Informed Consent Exclusion Criteria: * New York Heart Association (NYHA) Class IV (chronic or ambulatory) * Planned or previous implant of implantable cardioverter-defibrillator or pacemaker device * Patient's life expectancy is less than one year due to non cardiovascular disorders, in the opinion of the physician * Severe chronic obstructive pulmonary disorder (COPD) * Chronic Atrial Fibrillation at time of enrollment * ST segment elevation at time of electrocardiogram * Cognitive disease * Pregnancy or childbearing potential and not on reliable contraceptive * Anticipated compliance problem or participation in another competitive trial