This is especially the case for device-based therapeutics, where complete align- ment between the HF guideline and the device-based therapy guideline was deemed imperative (5). Some recommendations from earlier guidelines have been updated as warranted by new evidence or a better understanding of earlier evidence, whereas others that were no longer accurate or relevant or that were overlapping were modi ed; recommendations from previous guidelines that were similar or redundant were eliminated or consolidated when possible. The present document recommends a combination of life- style modi cations and medications that constitute GDMT. GDMT is speci cally referenced in the recommendations for treatment of HF (Section 6.3.2). Both for GDMT and other recommended drug treatment regimens, the reader is advised to con rm dosages with product insert material and to evaluate carefully for contraindications and drug-drug interactions. Table 2 is a list of documents deemed pertinent to this effort and is intended for use as a resource; it obviates the need to repeat already extant guideline recommendations. Additional other HF guideline statements are highlighted as well for the purpose of comparison and completeness. 2. De nition of HF HF is a complex clinical syndrome that results from any structural or functional impairment of ventricular lling or ejection of blood. The cardinal manifestations of HF are dyspnea and fatigue, which may limit exercise tolerance, and uid retention, which may lead to pulmonary and/or splanchnic congestion and/or peripheral edema. Some patients have exercise intolerance but little evidence of uid retention, whereas others complain primarily of edema, dyspnea, or fatigue. Because some patients present without signs or symptoms of volume overload, the term heart failure is preferred over congestive heart failure. There is no single diagnostic test for HF because it is largely a clinical diagnosis based on a careful history and physical examination. 