Differential Diagnosis for Syncope when Arms are Raised Above Head in a Patient with Lupus
- Single most likely diagnosis:
- Subclavian artery thrombosis or stenosis: This condition is likely due to the patient's history of lupus, which increases the risk of thrombotic events. Raising the arms above the head may cause a decrease in blood flow through the subclavian artery, leading to syncope.
- Other Likely diagnoses:
- Thoracic outlet syndrome (TOS): This condition involves compression of the subclavian artery or vein, which can be exacerbated by raising the arms above the head, leading to decreased blood flow and syncope.
- Vasovagal syncope: Although less specific to the action of raising arms, vasovagal syncope can be triggered by various factors, including stress, pain, or prolonged standing, and may be a consideration in a patient with lupus who experiences syncope.
- Do Not Miss diagnoses:
- Pulmonary embolism (PE): Although less directly related to the action of raising arms, PE is a potentially life-threatening condition that can cause syncope and must be considered, especially in a patient with lupus who may be at increased risk of thrombotic events.
- Cardiac tamponade: This is a life-threatening condition that can cause syncope and is a known complication of lupus. It should be considered in any patient with lupus who presents with syncope, regardless of the specific trigger.
- Rare diagnoses:
- Subclavian steal syndrome: This rare condition involves reversal of blood flow in the vertebral artery due to stenosis or occlusion of the subclavian artery, which can lead to syncope when the arms are raised above the head.
- Aortic dissection: Although rare, aortic dissection is a life-threatening condition that can cause syncope and should be considered in any patient with lupus who presents with syncope, especially if there are other symptoms such as chest or back pain.