Case Discussion

Dr. Raid Jastania

• A 65-year-old man presented to the emergency room with a recent (4-hour) history of severe chest pain radiating to his left arm. He was suspected to have had a "heart attack." Coronary angiography revealed a complete occlusion of the left anterior descending branch about 2 cm from its origin.

• He was given a therapeutic dose of recombinant human tissue plasminogen activator (t-PA). This treatment restored coronary artery blood flow, and his chest pain improved. Simultaneously, he was started on one tablet of aspirin per day.

• What therapeutic agent can be used to lyse the clots in coronary vessels?

• Why was aspirin given? What stage of hemostasis is affected by aspirin?

• What are natural anticoagulants?

• What are the causes of arterial thrombosis?

• What is the thrombus made of? • What causes arterial thrombosis? ...venous

thrombosis• What are the various fates of thrombi? • Which of these fates is clinically most significant

in the arterial circulation vs. the venous circulation?

• Describe the morphology (microscopy) of myocardial infarction?

• What are the major similarities between a myocardial and a cerebral infarct?

• What are the major differences between a myocardial and a cerebral infarct?

• What is the mechanism of formation of hemorrhagic infarcts in brain? • What are the types of infarcts?

• Seven days later, he noted swelling of both legs and feet and was found to have pitting edema of the legs; his liver was somewhat enlarged; and his neck veins (jugular) appeared full. He was given diuretics and asked to consume a salt-restricted diet. Because of considerable weakness, he remained in bed most of the time.

• What caused enlargement of the liver, edema, and fullness of the neck veins in this patient?

• What is the pathogenesis of pulmonary edema? • How does this type of edema differ from that seen

in acute inflammation?

• Are the alveolar septa normal in thickness?

• What effect would such a histologic picture have on gaseous exchange in the lung?

• What might the symptoms be?

• A few days later, he developed sudden pain in the lower right part of his chest, which was aggravated by taking a deep breath. Physical examination revealed that his left leg had developed more swelling than the right. X-ray of his chest showed a faint shadow in the peripheral part of the lower lobe of the right lung. Intravenous heparin was started. Two days later, he became very breathless and died suddenly.

• Did this patient have clinical features suggestive of pulmonary thromboembolism?

• Why are some infarcts red and others pale? • What is the most common symptom of pulmonary embolism? • How and when does pulmonary thromboembolism cause

sudden death? • When does pulmonary thromboembolism result in infarction?

• What conditions predispose to venous thrombosis? • What is the most common source of clinically

significant pulmonary emboli (ie, thrombi from which vessels in the leg)?

• What is the most common symptom associated with such venous thrombi?