Heart failure and the emergency department: epidemiology, characteristics, and outcomes.

It is widely recognized that the impact of heart failure on society is enormous. The research community has responded, resulting in an ongoing period of rapid advancement across a wide range of fields. The pace of progress is perhaps most apparent in the barrage of new and revised terminology appearing in the heart failure literature. Although sometimes confusing, the complexity of nomenclature directly reflects a growing appreciation that the symptom complex previously labeled "heart failure" is actually a spectrum of complex multisystem pathologies. Accordingly, clinicians must adopt a more sophisticated and more effective approach to evaluation and treatment that is increasingly based on objective measurement of outcome-linked physiologic parameters rather than the subjectively described symptom constellations relied on previously.