[Paradoxical embolism in patients with ischemic stroke]

Area of Science:

• Cardiology
• Neurology
• Vascular Medicine

Background:

• Ischemic stroke remains a leading cause of disability and mortality.
• Identifying the etiology of stroke, particularly cryptogenic stroke, is crucial for effective prevention.
• Paradoxical embolism (PE) is a potential, though often underdiagnosed, cause of ischemic stroke.

Purpose of the Study:

• To evaluate the risk of paradoxical embolism (PE) in patients with ischemic stroke.
• To determine the prevalence and characteristics of patent interatrial foramen (PIF) and shunts in stroke patients.
• To investigate the role of PIF and shunts in cryptogenic stroke etiology.

Main Methods:

• Contrast transthoracic echocardiography
• Contrast transcranial Doppler monitoring
• Transesophageal echocardiography
• Inclusion of 84 patients with ischemic stroke of known and unknown etiology.

Main Results:

• 64% of patients with known stroke etiology had PIF (51%) and/or shunts (13%), predisposing them to PE.
• PIF in these patients was typically of small anatomical and functional size.
• 94% of cryptogenic stroke patients showed a predisposition to PE, primarily due to PIF (88%).
• PIF was often the sole cause of stroke in cryptogenic cases, frequently associated with large functional shunts.

Conclusions:

• Patent interatrial foramen (PIF) is a significant risk factor for paradoxical embolism (PE) in ischemic stroke.
• PIF, especially when associated with large functional shunts, plays a critical role in cryptogenic stroke.
• Echocardiography and Doppler monitoring are essential tools for diagnosing PE risk factors in stroke patients.