Less than a minute or two.

The American College of Cardiology Foundation and the American Heart Association have jointly produced clinical practice guidelines for diagnosis and treatment of cardiovascular diseases since 1980. Writing committees are charged with assessing the evidence as an independent group of authors and with developing, updating, or revising recommendations for clinical practice. Practice guidelines are intended to assist healthcare providers in clinical decision making by describing a range of generally acceptable approaches for diagnosis, management, and prevention of specific diseases or conditions. Guideline recommendations reflect a consensus of the writing committee, are generally based on a thorough review of the available and current scientific evidence, and are intended to improve patient care. The areas where additional data are needed to better inform patient care are identified. Even in the absence of a strong evidence base, writing committees develop consensus-based recommendations where such recommendations are considered to be important.