Paradoxical embolism

Paradoxical embolism
Synonyms	Crossed embolism
Pronounce	N/A
Specialty	N/A
Symptoms	Stroke, Transient ischemic attack, Myocardial infarction
Complications	Pulmonary embolism, Systemic embolism
Onset	Sudden
Duration	Variable
Types	N/A
Causes	Patent foramen ovale, Atrial septal defect, Pulmonary arteriovenous malformation
Risks	Deep vein thrombosis, Pulmonary embolism, Right-to-left shunt
Diagnosis	Echocardiography, Transesophageal echocardiogram, Bubble study
Differential diagnosis	Ischemic stroke, Cryptogenic stroke, Pulmonary embolism
Prevention	Anticoagulation, Closure of patent foramen ovale
Treatment	Anticoagulant therapy, Thrombolysis, Surgical intervention
Medication	N/A
Prognosis	Variable, depends on underlying conditions and treatment
Frequency	Rare
Deaths	N/A

Paradoxical embolism is a rare but serious medical condition. It occurs when a blood clot or other embolus, which is formed in a vein, manages to pass into the arterial system. This can happen due to a defect in the heart, such as a patent foramen ovale or an atrial septal defect. The clot can then travel to any part of the body, including the brain, causing a stroke.

Causes

The main cause of paradoxical embolism is a venous thromboembolism (VTE) that passes through a right-to-left shunt in the heart. This can occur due to a congenital heart defect, such as a patent foramen ovale or an atrial septal defect, or due to a pulmonary arteriovenous malformation. Other causes can include deep vein thrombosis (DVT) or pulmonary embolism (PE).

Symptoms

The symptoms of paradoxical embolism can vary depending on where the embolus lodges in the body. If it lodges in the brain, it can cause symptoms of a stroke, such as sudden numbness or weakness in the face, arm, or leg, especially on one side of the body, sudden confusion, trouble speaking or understanding speech, sudden trouble seeing in one or both eyes, sudden trouble walking, dizziness, loss of balance or coordination, or sudden severe headache with no known cause.

Diagnosis

Diagnosis of paradoxical embolism can be challenging, as the symptoms can be similar to other conditions. However, if a patient presents with symptoms of a stroke and also has a known right-to-left shunt in the heart, a paradoxical embolism should be considered. Diagnostic tests can include a computed tomography (CT) scan or magnetic resonance imaging (MRI) of the brain, a transesophageal echocardiogram (TEE) to look for a right-to-left shunt in the heart, and a venous ultrasound to look for a DVT.

Treatment

Treatment of paradoxical embolism involves treating the underlying cause, such as closing the right-to-left shunt in the heart or treating the DVT or PE. This can involve medication, such as anticoagulants to prevent further clots from forming, or surgery to close the shunt or remove the clot.

See also

• Stroke
• Deep vein thrombosis
• Pulmonary embolism
• Patent foramen ovale
• Atrial septal defect