Evolution of our understanding of the aVR sign.

In patients presenting with signs and symptoms of an acute coronary syndrome (ACS) the combination of multilead ST depression and ST elevation in lead aVR, the electrocardiographic "aVR sign," has been associated with severe left main coronary artery stenosis or diffuse coronary artery disease and a high risk of death. Recent guidelines even suggest that the aVR sign may represent an ST-elevation myocardial infarction (STEMI) equivalent and therefore, an indication for emergent cardiac catheterization and reperfusion. The specificity of the aVR sign for left main disease, however, has been questioned as multiple additional high-risk clinical conditions have also been shown to be associated with the aVR sign. The purpose of this review is to provide a historic background of the aVR sign and to summarize the evolution of our understanding of this important electrocardiographic (ECG) phenomenon. Using two illustrative cases, we wish to highlight the significant risks associated both with under-appreciation of the aVR sign as well as hastily overreacting to the aVR sign.

A Conceptual Model for Episodes of Acute, Unscheduled Care.

We engaged in a 1-year process to develop a conceptual model representing an episode of acute, unscheduled care. Acute, unscheduled care includes acute illnesses (eg, nausea and vomiting), injuries, or exacerbations of chronic conditions (eg, worsening dyspnea in congestive heart failure) and is delivered in emergency departments, urgent care centers, and physicians' offices, as well as through telemedicine. We began with a literature search to define an acute episode of care and to identify existing conceptual models used in health care. In accordance with this information, we then drafted a preliminary conceptual model and collected stakeholder feedback, using online focus groups and concept mapping. Two technical expert panels reviewed the draft model, examined the stakeholder feedback, and discussed ways the model could be improved. After integrating the experts' comments, we solicited public comment on the model and made final revisions. The final conceptual model includes social and individual determinants of health that influence the incidence of acute illness and injury, factors that affect care-seeking decisions, specific delivery settings where acute care is provided, and outcomes and costs associated with the acute care system. We end with recommendations for how researchers, policymakers, payers, patients, and providers can use the model to identify and prioritize ways to improve acute care delivery.