Inclusion Criteria:  Male and female patients more than 18 years of age (no upper age limit) HF exacerbation requiring treatment with intravenous decongestive therapy in a hospital setting for an acute HF event during the past 12 calendar months. LVEF > 35% on a cardiac imaging study (echocardiogram, nuclear imaging, cardiac magnetic resonance imaging) performed during the past 12 calendar months. Shortness of breath associated with New York Heart Association (NYHA) functional class II, II, or ambulatory class IV. Willing to undergo an Abbott ICM implant and agree to remote ICM monitoring.  Exclusion Criteria:  Existing implantable cardioverter defibrillator (ICD), biventricular ICD, implantable cardiac monitor or pacemaker. Known or documented history AF or atrial flutter any time in past. Class I indication for primary or secondary prevention ICD Documented ST elevation myocardial infarction in the past 1calendar month. Life expectancy less than 1 year Unwilling or unable to cooperate with the protocol Participation in other clinical trials (observational registries are allowed with approval from the CDC).