Patent foramen ovale: Difference between revisions
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==Background==
==Background==
Patent foramen ovale (PFO) is a flap-like opening between the atrial septa primum and secundum at the location of the fossa ovalis that persists after 1 year of age. This inter-atrial communication gives potential for right-to-left shunting in the cardiovascular system. Although most patients with an isolated PFO are asymptomatic, there is increasing evidence being found that PFO is the culprit in [[Missile embolism|paradoxical embolic events]] and therefore, the relative importance of the anomaly is being re-evaluated.
*Flap-like opening between the atrial septa primum and secundum
*Occurs at fossa ovalis
*Persists beyond 1 year of age
*Inter-atrial communication allows right-to-left cardiac shunting
*Most patients with isolated PFO are asymptomatic
**But there is increasing evidence that PFO is the culprit in [[Missile embolism|paradoxical embolic events]]


==Clinical Features==
==Clinical Features==
*History of [[stroke]] or [[TIA]] of undefined etiology
*[[Stroke]] or [[TIA]] of undefined etiology
**Consider in young, healthy patients without risk factors for stroke
*[[Migraine]] or migraine-like symptoms
*[[Migraine]] or migraine-like symptoms
*Neurologic decompression sickness (seen in scuba divers)
*Neurologic [[decompression sickness]] (seen in scuba divers)
*[[Acute myocardial infarction]]
*[[Acute myocardial infarction]]
*Systemic embolism, such as renal infarction
*Systemic [[thromboembolism|embolism]], such as renal infarction
*Fat embolism
*Fat embolism
*Paradoxical embolism caused by right atrial tumors that increase right atrial pressure
*Paradoxical embolism caused by right atrial tumors that increase right atrial pressure
*Left-sided valve disease in carcinoid syndrome
*Left-sided valve disease in [[carcinoid syndrome]]


==Diagnosis==
==Differential Diagnosis==
*Color flow Doppler imaging: small "flame" of color signal may be seen in middle region of atrial septum
{{Missile embolism types}}
*[[Contrast echocardiography]] (Bubble Study): After obtaining optimal visualization of atrial septum on TTE or TEE, a bolus of agitated saline is injected to an antecubital vein. Subsequently, microbubbles appear in the right atrium. The study is positive for PFO if microbubbles appear in left atrium within 3 cardiac cycles of their appearance in the right atrium. Valsalva increases right atrial pressure and facilitates right-to-left shunting if present.
 
*2D TEE with contrast provides superior visualization and is therefore preferred for detecting PFO. When clinically indicated, 2D TEE with contrast is strongly recommended if transthoracic echo is negative.
==Evaluation==
*[[Echocardiography]]: color flow Doppler imaging
**Small "flame" of color signal may be seen in middle region of atrial septum
*[[Contrast echocardiography]] (Bubble Study)
**Bolus of agitated saline injected to antecubital vein
**Microbubbles appear in right atrium
***Study positive for PFO if microbubbles appear in left atrium within 3 cardiac cycles of their appearance in right atrium  
**Valsalva increases right atrial pressure and facilitates right-to-left shunting if present
*2D TEE with contrast provides superior visualization and is preferred
**Obtain 2E TEE with constrast if suspicion is high and TTE is negative


==Management==
==Management==
Most patients with PFO as isolated findings receive no treatment.
*Most patients with incidental or isolated PFO receive no treatment
When PFO is associated with an otherwise unexplained neurologic event, no consensus for treatment exists
*Treatment more common when PFO associated with unexplained neurologic event, but no consensus for treatment exists
 
===Medical Therapy===
===Medical Therapy===
*[[aspirin]] therapy alone in low risk patients
*[[Aspirin]] therapy alone in low risk patients
*addition of [[warfarin]] (INR 2-3)in high risk individuals
*[[Warfarin]] with ASA (INR 2-3) in high-risk individuals


===Surgical Care===
===Surgical Closure===
Indications for surgical closure of PFO
*Indications:
*PFO more than 25 mm in size
**PFO more than 25 mm in size
*Inadequate rim of tissue around defect
**Inadequate rim of tissue around defect
*percutaneous device failure
**Percutaneous device failure
Advantages of surgical closure
*Advantages of surgical closure
*permanent closure of defect
**Permanent closure of defect
*prevents future paradoxical emboli
**Prevents future paradoxical emboli
*no long-term anticoagulation and its risks
**No need for long-term anticoagulation
Percutaneous closure of PFO during cardiac catheterization is an emerging therapeutic option.
*Percutaneous closure
**Emergency therapeutic option


==See Also==
==See Also==

Latest revision as of 16:07, 25 September 2019

Background

  • Flap-like opening between the atrial septa primum and secundum
  • Occurs at fossa ovalis
  • Persists beyond 1 year of age
  • Inter-atrial communication allows right-to-left cardiac shunting
  • Most patients with isolated PFO are asymptomatic

Clinical Features

Differential Diagnosis

Missile embolism types

  • Intrapericardial foreign body
  • Systemic venous embolism
  • Right heart and pulmonary artery embolism
  • Pulmonary vein embolism
  • Left heart embolism
  • Coronary artery embolism
  • Paradoxical embolus (due to patent foramen ovale)

Evaluation

  • Echocardiography: color flow Doppler imaging
    • Small "flame" of color signal may be seen in middle region of atrial septum
  • Contrast echocardiography (Bubble Study)
    • Bolus of agitated saline injected to antecubital vein
    • Microbubbles appear in right atrium
      • Study positive for PFO if microbubbles appear in left atrium within 3 cardiac cycles of their appearance in right atrium
    • Valsalva increases right atrial pressure and facilitates right-to-left shunting if present
  • 2D TEE with contrast provides superior visualization and is preferred
    • Obtain 2E TEE with constrast if suspicion is high and TTE is negative

Management

  • Most patients with incidental or isolated PFO receive no treatment
  • Treatment more common when PFO associated with unexplained neurologic event, but no consensus for treatment exists

Medical Therapy

  • Aspirin therapy alone in low risk patients
  • Warfarin with ASA (INR 2-3) in high-risk individuals

Surgical Closure

  • Indications:
    • PFO more than 25 mm in size
    • Inadequate rim of tissue around defect
    • Percutaneous device failure
  • Advantages of surgical closure
    • Permanent closure of defect
    • Prevents future paradoxical emboli
    • No need for long-term anticoagulation
  • Percutaneous closure
    • Emergency therapeutic option

See Also

External Links

References

emedicine.Medscape.com

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