Background: Most patients with dyspnea primarily consult physicians in private practice. Heart failure and pulmonary disease are "epidemic" disorders and account for the majority of cases of dyspnea. There are approximately 24 million individuals in the United States with chronic obstructive pulmonary disease and another 10 million persons suffer from asthma. These illnesses generate in excess of 17 million physician office visits a year at a cost of over $10.4 billion. In addition, there are nearly 1.5 million new cases of heart failure in North America and Europe every year. The total direct cost of care for heart failure exceed $38 billion in the United States per year. Therefore, cost-effective management of these diseases is of paramount importance. Unfortunately, the rapid and accurate differentiation of heart failure from other causes of dyspnea in private practice is challenging. The symptoms of heart failure may be nonspecific, and signs are not sensitive enough and considerably overlap with those of pulmonary disease. In addition, signs of volume overload take time to evolve and may be completely absent in patients with acute heart failure.