A 67-year-old advertising executive complains of shortness of breath and occasional irregular heartbeat, which is not associated with exercise. The patient has a family history of heart disease. In which of the following positions should the patient be placed to optimize evaluation of cardiac valve patency? Prone, then supine. Head elevated 30 degrees and lying partly on the left side. Lithotomy position. Partly on the left side. Head elevated 30 degrees and lying partly on the right side.