Pulmonary embolism is the third most common cause of cardiovascular mortality after myocardial infarction and stroke. Atherosclerosis risk factors are the rule in outpatients with apparent unprovoked pulmonary embolism. Acute or chronic infections triggering immunothrombosis and inflammation are possibly the main mechanism in older unprovoked pulmonary embolism outpatients. Pulmonary embolism is frequently seen in unexplained acute exacerbation of chronic pulmonary obstructive disease, patients with community-acquired pneumonia, unexplained worsening of dyspnea, chronic atrial fibrillation patients, and in elderly patients with syncope, with or without an alternative explanation. A fast-track approach is the cornerstone of the initial workup. Pulmonary vascular obstruction of >25% is associated with pulmonary hypertension, right ventricular dysfunction, and clinical instability. Normal blood pressure cannot exclude impending clinical instability and in-hospital poor outcome in submassive pulmonary embolism. We suggest a multimodal approach to identify right ventricular dysfunction. A normal electrocardiogram or chest X-ray is unlikely in submassive or massive pulmonary embolism. Clinical condition, right ventricular dysfunction, and risk for major bleeding drive treatment choices. Patients who receive heparin until after hospital admission have increased mortality. Parenteral/oral anticoagulation and systemic thrombolysis are the foundation of treatment in low-risk and massive pulmonary embolism, respectively. A weight-adjusted unfractionated heparin regimen is recommended in those with impending unstable submassive pulmonary embolism and as adjunctive treatment in massive pulmonary embolism. Tenecteplase or alteplase is an option in <65 years and half-dose alteplase in >65 years pulmonary embolism patients. Also, low-dose alteplase is safe and effective in catheter- or ultrasound-directed thrombolysis.
