 A prospective, randomized, double-blind, placebo-controlled, international, multicentre, parallel-group comparison trial evaluating the efficacy and safety of single i.v. bolus tenecteplase plus standard anticoagulation as compared with standard anticoagulation in normotensive patients with acute pulmonary embolism and with echocardiographic and laboratory evidence of right ventricular dysfunction.Patients suffering from acute pulmonary embolism first symptoms occurring within 15 days confirmed by lung scanning or a positive spiral computed tomogram, or a positive pulmonary angiogram, presenting with right ventricular dysfunction on echocardiography and tested troponin I or T positive will be included in the study if they have no exclusion criteria.Patients in the investigational group will receive: Ø Tenecteplase as a single body-weight known or estimated adjusted IV bolus administered over 5 - 10 seconds not later than 30 minutes after randomization, and not later than 2 hours after the diagnosis of RV dysfunction Weight kg Dose in mg Dose in units Dose in ml60 30 mg 6000 U 6 ml60 to 70 35 mg 7000 U 7 ml70 to 80 40 mg 8000 U 8 ml80 to 90 45 mg 9000 U 9 ml90 50 mg 10000 U 10 mlØ and: concomitant therapy-Unfractionated heparin at a dose of 80 IUxKg-1 as an intravenous bolus, followed by an infusion of 18 IUxKg-1xh-1, to be administered immediately after randomization in all patients for at least 48 hours following randomization. Beyond this period, intravenous UFH may be substituted with subcutaneous heparin LMWH treatment. The bolus will be omitted when heparin was started before randomisation.Patients in the control group will receive Ø placebo as a single body-weight known or estimated adjusted IV bolus administered over 5 - 10 seconds not later than 30 minutes after randomization, and not later than 2 hours after the diagnosis of RV dysfunction. Weight kg Dose in ml60 6 ml60 to 70 7 ml70 to 80 8 ml80 to 90 9 ml90 10 mlØ and concomitant therapy with Unfractionated heparin 