The person is presenting with symptoms of CHF (dyspnea on exertion, pitting edema) as well as b/l basilar crackles all of which indicate a fluid overloaded state. In addition, there is cardiac dysfunction with improper pumping of the blood. Due to decreased cardiac output, the body perceives this as a "hypovolemic" state and causes the release of hormones like ADH and Renin in an effort to reabsorb water to bring the volume up. While the patient is having extracellular fluid accumulation (edema) the arterial blood volume is low which is what causes the "hypovolemic" state.