Thrombolytic therapy decreases mortality in patients with acute myocardial infarction and is now widely used in such patients. The choice of which thrombolytic agent to use in such patients, either streptokinase or recombinant tissue plasminogen activator (rt-PA), is based on regional preferences. The standard dose of streptokinase is 1.5 million units over 60 min, and the dose of rt-PA that is commonly used is 100 mg over 3 h. Experiments in animals have demonstrated that rt-PA produces continuing thrombolysis after it is cleared from the circulation and that thrombolysis is both increased and accelerated and bleeding is reduced when rt-PA is administered over a short time period. Based on these studies, there have been a number of recent trials examining alternative dosage regimens for rt-PA (bolus, front-loaded, and accelerated) in patients with myocardial infarction. To date, there is no convincing evidence that such regimens are superior to the more traditional rt-PA regimen. Future randomized trials will determine whether attempts to optimize rt-PA regimens will result in more efficacious treatment regimens. Interest in the use of thrombolytic therapy for patients with acute pulmonary embolism has been rekindled. The traditional 12- to 24-h regimens of streptokinase and urokinase are not optimal because of their logistic complexity and associated hemorrhagic complications. Clinical studies have demonstrated that rt-PA, 100 mg over 2 h, is an effective thrombolytic agent in patients with acute pulmonary embolism. In a recent double-blind trial in patients with acute pulmonary embolism, rt-PA, 0.6 mg/kg infused over 2 min, improved pulmonary perfusion. This bolus regimen is attractive because it is simple to administer. Future studies will compare the relative efficacy and safety of these two rt-PA regimens in patients with acute pulmonary embolism.

The 1980s has been a critical decade for the management of acute myocardial infarction (MI) because of the concentration in a very short time span of innovative results produced by a new generation of trials, in which thrombolysis has been the preeminent topic. The message coming from the results in the more than 50,000 patients included in the five key trials is simple and clear: thrombolysis, of any type, is the cornerstone of acute treatment of MI, and it works well to produce a very favorable epidemiologic picture. In the GISSI-2 trial, the nationwide adoption of a package of recommended treatments centered on thrombolysis for the overall population of patients with an acute MI has produced a relevant modification of the natural history of the disease, reducing the in-hospital mortality by about 40% in few years (from 13% to 8.8%). In particular, in the great majority of cases (patients aged less than 70 years in Killip class I with a first acute MI), the mortality has gone down to 3%, making a further reduction very hard to obtain with new drugs or strategies. In this context, we will discuss the concept of the relevance for clinical practice of obtaining even greater patency rates with new thrombolytic agents (hopefully more efficient and safe) or with new combinations of traditional agents.

Thrombolytic therapy is being used with increasing frequency in myocardial infarction (MI), pulmonary embolism, deep venous thrombosis (DVT), and peripheral arterial occlusion. Use of these agents, however, is hampered by concerns regarding safety and efficacy. Numerous laboratory parameters have been evaluated for monitoring the risk of bleeding complications, with levels of fibrinogen (and percentage of decrease) and fibrin/fibrinogen degradation products (FDPs) correlating to a variable extent with clinical bleeding. The bleeding time (BT) test has also been proposed as a potential predictor of bleeding during thrombolytic therapy. With respect to efficacy, the D-dimer fragment of FDPs, when corrected for soluble fibrin polymers, has been shown to correlate with clot lysis in venous thromboembolism but not MI. The BT also is being considered as a marker of lysis in patients with DVT. Given the increasing concomitant use of antiplatelet agents during thrombolytic therapy, the BT, as an in vivo test of hemostasis and platelet function, has potential utility as a noninvasive, adjunctive marker of thrombolytic efficacy.

Varicella pneumonia during pregnancy carries a significant mortality for both mother and fetus. The antiviral drug, acyclovir, appears to have decreased mortality in reported cases. We present a case report and review of the literature summarizing the experience to date with acyclovir in the treatment of varicella pneumonia during pregnancy.

A 65-year-old woman presented with recurrent Wegener's granulomatosis following two years of immunosuppressive therapy and three years of complete remission. At her initial presentation, she had a characteristic x-ray picture showing multiple nodules with total resolution of these findings at three months. Five years later, at the time of clinical relapse, her chest x-ray film showed bilateral diffuse infiltrative disease. This change in radiologic presentation upon relapse of Wegener's has not previously been reported. Other unusual features include diffuse infiltrates as the pulmonary presentation and the long interval between cessation of therapy and relapse. We review the radiologic manifestations of Wegener's granulomatosis.