Long Term Effects of Treating Submassive Pulmonary Embolism With Ultra-sound Accelerated Thrombolysis

Inclusion Criteria: * Patients with acute (\< or = 14 days)symptomatic pulmonary embolism by CT Angiogram of the thorax with embolus involving at least one main or lower lobe pulmonary artery and RV:LV ratio \> 0.9 Exclusion Criteria: * age \> 80 * Recent thrombolytic therapy (with in 4 days) * Active bleeding or know bleeding diathesis * Known coagulopathy (including treatment with vitamin K antagonists) INR \> 3 and/or PTT \> 50 * Thrombocytopenia (PLT cound \< 100,000) * History of any intracranial or intraspinal surgery, trauma or bleed * Intracranial neoplasms, AVM, or aneurysm * Recent (\< 1 month) GI bleed * Recent (\< 3 months) internal eye surgery or hemorrhagic retinopathy * Recent (\< 7 days) major surgery, trauma, or obstetrical delivery * Renal insufficiency with eGFR \< 45 ml/min * Known allergy, hypersensitivity, or thrombocytopenia from heparin or tPA * Hemodynamic instability defined as need for cardiopulmonay resuscitation, Systolic BP \> 90 mm Hg for \> 15 min or need for pressor agents to maintain BP \> 90. * Severe Hypertension (sustained systolic \> 180 mm Hg or diastolic \> 90 mm Hg. * Pregnant patients * known right to left shunt * Large (\>10 mm)intracardiac thrombus * Use of thrombolytics or glycoprotein IIb/IIIa antangonists within 3 days of inclusion. * Life expectancy \< 30 days