Admission findings: A 18-year-old girl was admitted because of dyspnea and chest pain at rest. Her previous medical history was unremarkable except that oral contraceptives had been newly prescribed a month before admission. There was a family history of thrombosis or bleeding in several first-degree relatives.
Investigations: Echocardiography and computed tomography revealed bilateral pulmonary embolism caused by a large right atrial thrombus. Laboratory analysis showed prolonged thrombin time and subnormal levels of fibrinogen. Genetic analysis revealed a previously unreported fibrinogen mutation (hypodysfibrinogenemia Dresden I) in the patient and in her relatives.
Diagnosis: These findings indicated that the pulmonary embolism had been caused by a right atrial thrombus in a patient with hypodysfibrinogenemia. Recently initiated intake of oral contraceptives had led to manifestation of the disease.
Treatment: Anticoagulation with heparin followed by coumarin achieved complete resolution of symptoms.
Conclusion: The atypical course of thromboembolism in this young woman was caused by an underlying hereditary thrombophilia and manifested itself by the prothrombotic effect of newly taken oral contraceptives. If a detailed family history had been obtained before prescribing these drugs thrombotic or bleeding events in the patient's family would have been revealed and could have prevented thromboembolism. This case illustrates the importance of current guidelines according to which a family history should be obtained before starting oral contraceptives.