Patent Foramen Ovale/Atrial Septal Aneurysm

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Cryptogenic stroke due to paradoxical embolus

• Echocardiographic evidence of patent foramen ovale (PFO) and/or atrial septal aneurysm (ASA)

GENERAL CONSIDERATIONS

• A PFO is a flaplike opening between the atrial septal primum and secundum at the level of the fossa ovalis that persists after age 1 year

• An ASA is a congenital outpouching in the region of the fossa ovalis that is frequently associated with a PFO

• PFO is detected in 10–15% of the population by contrast echocardiography, and 25% have a probe-patent foramen ovale at autopsy

• Potential cause of transient ischemic attack (TIA) or cryptogenic stroke due to paradoxical emboli

• Combination of PFO and ASA has the highest risk of recurrent stroke

• Any condition that increases right atrial pressure more than left atrial pressure (including the Valsalva maneuver) can cause paradoxical right-to-left shunting across the PFO and lead to embolic events

• At present, no consensus guidelines exist for the treatment of PFO. However, it is reasonable to proceed with closure in a patient with a history of stroke

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Most patients are asymptomatic

• Cryptogenic stroke or TIA

PHYSICAL EXAM FINDINGS

• Physical exam is usually normal except for neurologic deficits in patients with stroke

DIFFERENTIAL DIAGNOSIS

• Atrial septal defect

• Bowed, hypermobile, but intact atrial septum without aneurysm

• Other causes of cryptogenic stroke, such as mitral valve prolapse, left atrial myxoma, and infective endocarditis

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• No specific lab tests

ELECTROCARDIOGRAPHY

• No specific findings

IMAGING STUDIES

• Transthoracic echocardiography with saline contrast:

  • – The appearance of “microbubbles” in the left atrium within 3 cardiac cycles of their appearance in the right atrium after agitated saline contrast injection suggests a PFO

  • – A PFO may also be detected with color-flow Doppler in the middle region of the atrial septum

  • – When clinically indicated, a transesophageal echocardiogram is recommended for patients with “negative” transthoracic echocardiogram results because of the higher sensitivity

DIAGNOSTIC PROCEDURES

• Transesophageal echocardiography:

  • – Provides superior visualization of the atrial septum and is therefore preferred over contrast transthoracic echocardiography

  • – Distinguishes a PFO from a small atrial septal defect and diagnoses ASAs

TREATMENT

CARDIOLOGY REFERRAL

• Patients with an embolic event and findings of a PFO and/or ASA by echocardiographic imaging

HOSPITALIZATION CRITERIA

• Stroke or other embolic event

MEDICATIONS

• Asymptomatic patients:

  • – No specific treatment is warranted, ...