In a middle‑aged or older adult with an acute ischemic stroke and no obvious atherosclerotic risk factors, how is a left atrial myxoma related to the stroke and what diagnostic and treatment steps should be taken?

Left Atrial Myxoma and Acute Ischemic Stroke

In a middle-aged adult presenting with acute ischemic stroke without traditional atherosclerotic risk factors, left atrial myxoma is a critical cardioembolic source that requires urgent transesophageal echocardiography for diagnosis and emergent surgical excision to prevent recurrent stroke and sudden death. 1

Epidemiology and Embolic Risk

Left atrial myxoma is the most common primary cardiac tumor, accounting for approximately 50% of all benign cardiac neoplasms, with an autopsy incidence of 0.02%. 1, 2 These tumors carry a substantial embolic burden:

• Overall embolism rate is 25%, with embolic stroke being the presenting symptom in up to 50% of cases. 1, 3
• Myxomas with villous or papillary surface architecture have markedly higher embolic potential compared to smooth-surface tumors. 1, 3
• The mechanism of stroke involves either embolization of thrombus formed on the tumor surface or direct embolization of tumor fragments. 1, 3

Pathophysiology of Stroke

The embolic mechanism operates through two pathways: 1

1. Thrombus formation on the friable tumor surface, which then embolizes to cerebral circulation
2. Direct tumor fragment embolization from the myxoma itself, particularly in villous morphology variants

Most myxomas arise from the interatrial septum at the fossa ovalis region in the left atrium. 1, 2

Diagnostic Algorithm

Step 1: Recognize the Clinical Pattern

In a patient presenting with acute ischemic stroke who lacks conventional atherosclerotic risk factors (hypertension, diabetes, hyperlipidemia, smoking), immediately consider cardioembolic sources. 4, 5

Key clinical clues suggesting myxoma:

• Middle-aged patient (typically 40s-50s) without vascular risk factors 4, 5
• Multiple cerebral infarcts or "silent" infarcts on imaging 5
• History of intermittent palpitations, chest pain, or syncope 5
• Constitutional symptoms (fever, weight loss) may be present 1

Step 2: Obtain Transesophageal Echocardiography

Transesophageal echocardiography (TEE) is the first-line cardiac imaging modality for younger adults with unexplained cerebrovascular events because it has higher sensitivity than transthoracic imaging for detecting cardiac tumors. 1, 3

• TEE should be performed urgently in the cryptogenic stroke workup. 1
• Transthoracic echocardiography has lower sensitivity and may miss smaller tumors. 3
• Cardiac MRI or CT provides additional characterization for surgical planning once myxoma is identified. 1, 2

Step 3: Assess Tumor Morphology

Villous features on imaging indicate higher embolic risk and reinforce the need for prompt surgery. 1, 3

The morphologic appearance directly correlates with embolic potential—friable, papillary surfaces generate thrombus and shed fragments more readily than smooth surfaces. 1

Treatment Recommendations

Surgical Excision: The Only Definitive Treatment

Urgent surgical resection of left-sided cardiac myxoma is advised to prevent recurrent stroke, sudden death, and cardiac obstruction (Class IIa recommendation, Level of Evidence C-LD). 1, 3

All symptomatic left atrial myxomas require surgical resection. 1, 2 The surgical approach must include:

• Complete tumor removal with adequate margin of atrial septum to prevent recurrence (occurs in 1-5% of sporadic cases) 1
• Histopathologic confirmation is mandatory 1
• Surgery should be performed urgently, not electively 2, 3

Critical Management Pitfalls

Anticoagulation or antiplatelet therapy alone is inadequate and does not prevent embolic complications or relieve mechanical obstruction—it should not be used as definitive therapy. 1, 2, 3

This is a common error: while anticoagulation may seem intuitive for preventing emboli, it:

• Does not address the mechanical obstruction caused by the tumor 2
• May increase bleeding risk without reducing embolic events 2
• Cannot prevent tumor fragment embolization 1

Do not delay surgery for anticoagulation. The priority is tumor removal, not medical management. 2, 3

Thrombolytic Therapy Considerations

For patients presenting within the thrombolytic window, intravenous alteplase can be administered if standard eligibility criteria are met. 6, 7 However:

• Carefully monitor for hemorrhagic transformation, as this may delay necessary cardiac surgery 6
• The extent of anticoagulation therapy post-thrombolysis requires close surveillance 6
• Thrombolysis does not replace the need for urgent surgical excision 6, 7

Special Considerations

For patients with right-sided cardiac tumors, evaluate for patent foramen ovale (PFO) because paradoxical embolism of tumor fragments or venous thrombus can occur. 1, 3

Post-Operative Management

• Long-term follow-up with periodic echocardiography to monitor for recurrence 1
• Recurrence rates are 1-5% in sporadic cases but higher in familial syndromes 1
• Histopathology will show myxoma cells (lepidic cells) with abundant myxoid matrix, vascular channels, and often hemorrhage and hemosiderin deposition 1, 2

Clinical Bottom Line

The diagnostic pathway is straightforward: cryptogenic stroke in a middle-aged patient → urgent TEE → identify myxoma → assess morphology → emergent surgical excision. 1, 3 Do not waste time with anticoagulation trials or delayed surgical planning—the 25% embolism rate and risk of sudden death mandate urgent intervention. 1, 3