A 65-year-old woman who had been discharged from the hospital following a myocardial infarction returned to the emergency room several weeks later because of the sudden onset of pain in her right lower extremity. The attending physician noticed that the patient’s leg was pale and cool from the knee down. Furthermore, he was unable to detect a pulse over the dorsal pedal and popliteal arteries. A good femoral pulse, however, was palpable in the inguinal region. Upon questioning, the patient stated that she was sent home with blood thinning medication because tests had revealed that the heart attack had caused a blood clot to form within her heart. The doctors were worried, she added, that “ a piece of the clot could break off and go to other parts of the body Which side of the heart did the blood clot form in?