Pulmonary embolism as a cause of unexplained sinus tachycardia after right ventricular myocardial infarction.

We present the case of a patient who developed new-onset asymptomatic sinus tachycardia after undergoing treatment for a right ventricular myocardial infarction. Even after excluding heart failure, infection and bleeding, the sinus tachycardia persisted. Computed tomography pulmonary angiography showed multiple bilateral pulmonary emboli. The vital sign abnormality resolved after treatment with an anticoagulant. We postulate that the pulmonary emboli originated from thrombi that were formed in the infarcted and dysfunctional right ventricle. Pulmonary embolism is a very rare complication of right ventricular myocardial infarction, and patients usually present with pleuritic chest pain. Our case highlights that asymptomatic sinus tachycardia could be a presenting feature of pulmonary embolism after the occurrence of a right ventricular myocardial infarction. A high index of suspicion is warranted in order to detect this potentially lethal complication.