Przetrwały otwór owalny – Etiologia i przyczyny

Przetrwały otwór owalny
Etiologia i przyczyny

Przetrwały otwór owalny (PFO) jest anatomiczną pozostałością połączenia między przedsionkami serca z okresu płodowego, utrzymującą się u około 25-34% populacji dorosłych. Jego patogeneza pozostaje nie do końca wyjaśniona, choć istnieją dowody na udział czynników genetycznych oraz współistnienie z innymi anomaliami serca, takimi jak tętniak przegrody międzyprzedsionkowej (ASA). PFO umożliwia paradoksalną zatorowość poprzez bezpośredni przeciek krwi z prawego do lewego przedsionka, co może prowadzić do udarów niedokrwiennych, zwłaszcza u młodszych pacjentów z udarami kryptogennymi. Ryzyko powikłań wzrasta wraz z wielkością otworu, obecnością ASA oraz czynnikami zwiększającymi ciśnienie w prawym przedsionku, takimi jak kaszel czy wysiłek fizyczny. Skala RoPE jest użytecznym narzędziem do oceny prawdopodobieństwa etiologicznego udziału PFO w udarze.

Etiologia przetrwałego otworu owalnego (Patent foramen ovale, PFO)

Przetrwały otwór owalny (Patent Foramen Ovale, PFO) jest pozostałością prawidłowej anatomii płodowej, która nieprawidłowo utrzymuje się w życiu dorosłym. Jest to otwór między górną częścią przegrody międzyprzedsionkowej, który występuje u około 25% populacji dorosłych na całym świecie¹². Badania autopsyjne wykazały, że PFO występuje u 25-30% osób³, przy czym niektóre źródła podają nawet wyższy odsetek – do 34% populacji dorosłych⁴.

Tło fizjologiczne

Otwór owalny (foramen ovale) jest strukturą tunelowatą między górną częścią przegrody międzyprzedsionkowej (septum secundum) a dolną częścią (septum primum)¹. W życiu płodowym otwór owalny jest niezbędny dla przepływu krwi przez przegrodę międzyprzedsionkową, umożliwiając krwi omijanie płuc płodu, które nie funkcjonują do momentu narodzin⁵. Po urodzeniu, gdy płuca zaczynają pracować, ciśnienie w lewym przedsionku wzrasta, co zwykle powoduje zamknięcie tego otworu i połączenie septum primum z septum secundum⁶. Proces ten zazwyczaj kończy się w ciągu pierwszych kilku miesięcy lub lat życia⁷.

Nieznana etiologia

Dokładna przyczyna, dlaczego otwór owalny pozostaje otwarty u niektórych osób, nie jest w pełni wyjaśniona. Większość źródeł medycznych wskazuje, że etiologia PFO jest nieznana⁸⁹. Nie zidentyfikowano również konkretnych czynników ryzyka dla tego stanu¹⁰¹¹. Jak stwierdza jedno z źródeł: „Badacze nie wiedzą, co powoduje patent foramen ovale”².

Czynniki genetyczne

Istnieją pewne dowody sugerujące udział czynników genetycznych w patogenezie PFO:

Genetyka może odgrywać rolę w utrzymywaniu się otworu owalnego⁸¹²
Dziedziczenie i genetyka mogą być czynnikami wpływającymi na brak zamknięcia otworu¹³
Istnieją ograniczone dane na temat podstawowych przyczyn PFO, ale istnieją pewne dobre dowody na udział czynników genetycznych¹³

Stany współistniejące

PFO często współistnieje z innymi nieprawidłowościami anatomicznymi serca, które mogą wpływać na jego utrzymywanie się:

Tętniak przegrody międzyprzedsionkowej (atrial septal aneurysm, ASA) – nadmierna ruchomość przegrody międzyprzedsionkowej, która zwiększa ryzyko udarów związanych z PFO¹⁴¹⁵
Zastawka Eustachiusza – pozostałość zastawki zatoki żylnej¹
Sieć Chiariego – włókniste pasma w prawym przedsionku¹¹⁰
Anomalia Ebsteina – wada rozwojowa zastawki trójdzielnej¹⁶¹⁷

PFO występuje częściej u noworodków z wrodzonymi wadami serca⁷¹⁸. W niektórych przypadkach złożonych wrodzonych wad serca PFO może być korzystne i konieczne, ponieważ otwór może pozwalać krwi przechodzić z jednej strony do drugiej, zapewniając niezbędny przepływ do obszaru, który nie otrzymuje prawidłowego przepływu krwi⁵.

Czynniki nabyte

Chociaż większość przypadków PFO jest wrodzona, istnieją doniesienia o możliwości nabycia tego stanu w życiu dorosłym:

PFO może być wrodzone lub nabyte, przy czym to drugie może rozwinąć się u osoby dorosłej w wyniku urazu, infekcji lub stanu zapalnego tkanki wokół serca¹⁹
Długotrwałe podwyższenie ciśnienia w prawym przedsionku może zwiększać częstość występowania PFO²⁰

Mechanizmy patogenezy – paradoksalna zatorowość

Najważniejszym mechanizmem patogennym związanym z PFO jest zjawisko paradoksalnej zatorowości, które może prowadzić do poważnych powikłań¹. PFO pozwala na bezpośredni przepływ krwi między prawym a lewym przedsionkiem, tworząc potencjalną drogę dla materiału zatorowego.

Mechanizm paradoksalnej zatorowości

Proces paradoksalnej zatorowości polega na przejściu materiału zatorowego (najczęściej skrzeplin) z krążenia żylnego do tętniczego z pominięciem filtra płucnego:

Skrzepliny tworzące się w układzie żylnym (najczęściej w żyłach kończyn dolnych) mogą przedostawać się do prawego przedsionka²¹
W normalnych warunkach skrzepliny te byłyby filtrowane przez płuca, ale obecność PFO umożliwia ich przejście bezpośrednio do krążenia systemowego²²
Skrzepliny mogą następnie przedostawać się do mózgu, powodując udar niedokrwienny, lub do innych narządów, powodując zawał²³

Struktura tunelowata PFO i skłonność do zastoju przepływu mogą również sprzyjać tworzeniu się skrzeplin in situ¹. James Lock zaproponował teorię, że anatomia PFO powoduje tworzenie się ślepego zaułka między septum primum a septum secundum, predysponując osoby do hemostazy i tworzenia skrzeplin²⁴.

Czynniki zwiększające ryzyko paradoksalnej zatorowości

Ryzyko paradoksalnej zatorowości jest zwiększone przez czynniki, które powodują wzrost ciśnienia w prawym przedsionku:

Każdy stan zwiększający ciśnienie w prawym przedsionku bardziej niż w lewym może indukować paradoksalny przepływ i prowadzić do zdarzeń zatorowych²⁴
Czynniki takie jak napinanie się podczas kaszlu, kichania lub podnoszenia ciężarów mogą wpływać na mechanizm powstawania udaru przy PFO²⁵
Ćwiczenia fizyczne lub zmiany w geometrii klatki piersiowej (np. po operacji) mogą prowadzić do zmian ciśnienia wewnątrz serca, zwiększając przepływ krwi przez PFO²⁶

Czynniki anatomiczne wpływające na ryzyko zatorowości

Cechy anatomiczne PFO mają wpływ na ryzyko powikłań:

Wielkość otworu i stopień przecieku są istotne – duże PFO ze znaczącym przeciekiem wiąże się z wyższym ryzykiem zdarzeń niedokrwiennych mózgu²⁷
Obecność tętniaka przegrody międzyprzedsionkowej (ASA) wraz z PFO zwiększa ryzyko wystąpienia udaru pięciokrotnie²⁷
Około 5% populacji ma szczególnie niebezpieczne formy PFO, które stwarzają wystarczająco wysokie ryzyko zdarzeń klinicznych, takich jak śmierć, udar, zawał mięśnia sercowego lub zator oczny, trzewny i obwodowy²⁸

PFO jako przyczyna udaru kryptogennego

Najsilniejszy związek epidemiologiczny PFO dotyczy udarów kryptogennych, czyli takich, których przyczyna nie może być ustalona pomimo dokładnej diagnostyki¹⁸²⁹.

Dowody epidemiologiczne

Istnieje znacząca korelacja między PFO a udarami kryptogennymi:

Dane z 1988 roku wykazały, że 30-40% młodych pacjentów z udarem kryptogennym miało PFO³⁰
PFO występuje u około 40-50% osób z udarem kryptogennym, podczas gdy w populacji ogólnej wynosi około 25%¹⁴
Przetrwały otwór owalny wpływa na około 30-40% osób, które miały niewyjaśniony udar²

Związek między PFO a udarem jest szczególnie wyraźny u młodszych pacjentów:

PFO z większym prawdopodobieństwem może być przyczyną udaru u młodego dorosłego, ponieważ młodsze osoby mają mniej czynników ryzyka udaru z innych przyczyn³¹¹⁶
Należy rozważyć PFO jako czynnik etiologiczny w ostrym udarze niedokrwiennym, szczególnie u młodszych pacjentów bez konwencjonalnych czynników ryzyka²⁰

Skala RoPE (Risk of Paradoxical Embolism)

W celu oceny prawdopodobieństwa, że PFO jest przyczyną udaru kryptogennego, opracowano skalę RoPE:

Skala RoPE jest cennym narzędziem do przewidywania roli PFO w ryzyku udaru³³
Wysoki wynik wskazuje na wysokie prawdopodobieństwo, że udar indeksowy był spowodowany przez PFO³³
Skala RoPE wskazuje na zwiększone ryzyko udaru, jeśli wynik wynosi co najmniej 4²⁷

Warto jednak podkreślić, że nawet u osób z wysokim ryzykiem nawrotu udaru, określonym przez skalę RoPE, średnie ryzyko nawrotu udaru jest bardzo niskie i trudno jest przewidzieć z pewnością osoby o podwyższonym ryzyku²⁷.

Ograniczenia związku przyczynowego

Istnieją pewne ograniczenia w ustaleniu związku przyczynowego między PFO a udarem:

Kilka badań nie wykazało zwiększonego ryzyka udaru u bezobjawowych pacjentów z PFO²⁹
Ryzyko nawrotu udaru jest niskie u pacjentów, którzy mieli udar, który można przypisać PFO²⁹
Większość udarów nie wynika z PFO, a nawet osoby z PFO często mają udary z innych przyczyn¹⁶
Prospektywny związek PFO z ryzykiem udaru jest niekonsekwentny, ponieważ około jedna trzecia PFO w kontekście udaru jest przypadkowa³⁴

Wystąpienie PFO u osób w średnim wieku z tradycyjnymi czynnikami ryzyka sercowo-naczyniowego lub drobnymi podkorowymi zawałami nie oznacza, że PFO jest czynnikiem przyczynowym udaru³³.

Inne stany związane z PFO

Oprócz udarów kryptogennych, PFO było wiązane z różnymi innymi stanami klinicznymi, chociaż mechanizmy i siła tych powiązań są bardziej kontrowersyjne.

Migrena

Istnieją doniesienia o związku między PFO a migreną, szczególnie migreną z aurą:

Kilka badań zaobserwowało wyższą częstość występowania PFO u pacjentów cierpiących na migrenę, szczególnie u pacjentów z aurą³⁵
Niektóre osoby z PFO cierpią na bóle głowy podobne do migreny³⁰
Dorośli z PFO mają zwiększoną szansę na występowanie migreny, szczególnie tych, w których tworzą się aureole w polu widzenia²³

Proponowane mechanizmy związku między PFO a migreną obejmują:

Paradoksalną mikroembolizację, która może działać jako potencjalny wyzwalacz ataków migreny³⁵
Przepływ z prawa na lewo neuroprzekaźników, takich jak serotonina, które nie są neutralizowane w płucach, co może wyzwalać określone receptory w mózgu³⁵
Mieszanie się natlenowanej i nienatlenowanej krwi w sercu³⁶

Dowody na związek między PFO a migreną są jednak mieszane i kontrowersyjne:

Niektórzy eksperci twierdzą, że badania wykazujące związek między PFO a migreną nie były odpowiednio zaprojektowane³⁶
Nie ma dobrej jakości naukowych dowodów, że ten związek w ogóle istnieje³⁶
Inni twierdzą, że dowody są mieszane, ale istnieje więcej dowodów potwierdzających związek między PFO a migreną z aurą niż dowodów na jego obalenie³⁶

PFO jest czynnikiem ryzyka dla nurków i pilotów wysokościowych, którzy są narażeni na szybkie zmiany ciśnienia:

Związek między PFO a chorobą dekompresyjną u nurków i pilotów wysokościowych, którzy szybko przechodzą ze środowiska wysokiego do niskiego ciśnienia, został udokumentowany³⁷
Prawo-lewy przeciek, taki jak PFO, pozwala pęcherzykom azotu omijać filtr płucny, zwiększając ryzyko, że zwykle bezpieczne wynurzenia spowodują zatorowość systemową³⁸
Powikłanie to jest unikalne dla nurków³⁹

W badaniu kontrolnym z udziałem nurków z chorobą dekompresyjną i zamknięciem PFO, czterech nadal miało chorobę dekompresyjną w 10-letnim okresie obserwacji³⁸.

Inne powikłania

PFO wiązano również z innymi stanami klinicznymi:

Hipoksemia (niskie stężenie tlenu we krwi)¹⁹⁴⁰
Nadciśnienie płucne¹⁹
Zespół platypnea-orthodeoxia (duszność i niedotlenienie w pozycji pionowej)¹³
Chorobę wysokościową⁴⁰
Obturacyjny bezdech senny⁴⁰⁴¹
Migotanie przedsionków¹⁹
Zawał mięśnia sercowego – zator paradoksalny może prowadzić do zawału mięśnia sercowego¹⁵⁴²
Zespół przewlekłego zmęczenia – według niektórych badaczy 90% pacjentów z zespołem przewlekłego zmęczenia ma PFO⁴¹

Ponadto, PFO może być czynnikiem ryzyka udaru u dzieci z anemią sierpowatą, ponieważ są one predysponowane do zakrzepicy i podwyższenia ciśnienia w prawej części serca, co może sprzyjać paradoksalnemu zatorowi³⁷.

Podsumowanie etiologii PFO

Przetrwały otwór owalny (PFO) jest konsekwencją braku zamknięcia otworu owalnego, który jest prawidłową strukturą w sercu płodu²⁹. Dokładna przyczyna, dlaczego otwór owalny pozostaje otwarty u niektórych osób, jest nieznana, choć czynniki genetyczne mogą odgrywać rolę⁸.

PFO występuje u około 25% populacji ogólnej i jest często bezobjawowe². Jego znaczenie kliniczne związane jest głównie z ryzykiem paradoksalnej zatorowości, która może prowadzić do udaru mózgu, szczególnie u młodszych pacjentów bez tradycyjnych czynników ryzyka²⁰.

Czynniki anatomiczne, takie jak wielkość PFO i obecność tętniaka przegrody międzyprzedsionkowej, mogą zwiększać ryzyko powikłań²⁷. PFO wiązano również z innymi stanami klinicznymi, takimi jak migrena, choroba dekompresyjna, hipoksemia i zawał mięśnia sercowego, choć związki te są bardziej kontrowersyjne i wymagają dalszych badań³⁵³⁷.

Zrozumienie etiologii i mechanizmów patofizjologicznych PFO jest kluczowe dla odpowiedniego leczenia pacjentów z tym schorzeniem, szczególnie tych, którzy doświadczyli udaru kryptogennego lub innych powikłań potencjalnie związanych z PFO¹⁸.

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Materiały źródłowe

#1 Patent Foramen Ovale – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK493151/
Patent foramen ovale (PFO) occurs when a remnant of normal fetal anatomy abnormally persists into adulthood. […] The foramen ovale is a tunnel-like space between the overlying septum secundum and septum primum. It closes in 75% of infants when the septum primum and secundum fuse. In utero, the foramen ovale is necessary for blood flow across the fetal atrial septum. […] In approximately 25% of people, a PFO persists into adulthood. PFOs may be found in association with: Atrial septal aneurysms (a redundancy of the interatrial septum), Eustachian valves (a remnant of the sinus venosus valve), Chiari networks (filamentous strands in the right atrium). […] Clinically significant PFOs result in adverse consequences by 2 mechanisms: Serving as a conduit for paradoxical embolization from the venous side to the systemic circulation, Because of their tunnel-like structure and propensity for stagnant flow, they may serve as a nidus for in situ thrombus formation.
#2 Patent Foramen Ovale (PFO): Symptoms, Causes & Treatment
https://my.clevelandclinic.org/health/diseases/17326-patent-foramen-ovale-pfo
Patent foramen ovale (PFO) is a small hole between the upper right and left chambers (atria) of your heart. Patent foramen ovale occurs when the flap still exists after birth. Researchers dont know what causes patent foramen ovale. Patent foramen ovale affects about 25% of people worldwide. PFO impacts about 30% to 40% of people whove had an unexplained stroke. Usually, patent foramen ovale causes no problems. But PFO may let a blood clot travel from the right to the left side of your heart. Your heart could pump the clot into your body. If the clot reaches your brain, it could cut off the blood supply. This would cause an ischemic stroke. The clot may also damage your other organs, such as your kidneys or your heart.
#3 Patent foramen ovale – UpToDate
https://www.uptodate.com/contents/patent-foramen-ovale
Patent foramen ovale (PFO) is a congenital cardiac lesion that frequently persists into adulthood. Although most patients with a PFO are asymptomatic, a variety of clinical manifestations may be associated with PFO, most importantly cryptogenic stroke. […] PFO was found in 25 to 30 percent of individuals in an autopsy study and in a community-based transesophageal echocardiography (TEE) study. […] Probe-patent PFO was present in 27 percent; the prevalence and size were similar in males and females.
#4 Patent Foramen Ovale (PFO) Closure: Procedure & Indications
https://www.icrjournal.com/articles/patent-foramen-ovale-closure-state-art?language_content_entity=en
Patent foramen ovale (PFO) is a common abnormality affecting between 20% and 34% of the adult population. […] In a significant proportion of individuals, the primum and secundum atrial septa do not fuse, and the foramen ovale remains incompletely closed. […] Some PFOs may open widely, providing a conduit for thrombus, air or vasoactive peptides to travel from the venous to arterial circulation causing a paradoxical embolus. […] The presumed cause of stroke is paradoxical embolus. […] The PFO channel briefly provides a communication between the atria. […] The presence of AF in the context of a stroke is an indication for anticoagulation, and closure of a PFO is not indicated. […] A longitudinal, non-randomised follow-up study showed that PFO closure reduced both symptomatic neurological events and total brain lesions among recreational divers with PFO and decompression illness, compared with those who continued to dive without closure.
#5 Patent Foramen Ovale (PFO) | American Stroke Association
https://www.stroke.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/patent-foramen-ovale-pfo
A hole in your heart would seem to be the very definition of a „problem.” Yet more than a quarter of the population has one type of hole in the heart, called a patent foramen ovale (PFO), and for most people it causes no adverse health effects. In fact, the vast majority of those affected don’t even know it. […] PFOs, on the other hand, are normal before birth but may fail to close after birth. The foramen ovale is a hole in the wall between the left and right atria of every human fetus. This hole allows blood to bypass the fetal lungs, which cannot work until air is inhaled after birth. […] Problems can arise when pressures within the heart change for various reasons and the foramen ovale flap never completely sealed, allowing blood to flow from the right atrium to the left. If that blood contains a clot it can travel elsewhere in the body including the brain, which could lead to a stroke. […] In some cases of more complex congenital heart disease, a PFO may be helpful and necessary. The opening can allow blood to cross from one side or the other to provide necessary flow to an area that is not receiving normal blood flow.
#6 Patent Foramen Ovale Causes and Diagnoses | Northwestern Medicine
https://www.nm.org/conditions-and-care-areas/neurosciences/comprehensive-stroke-centers/patent-foramen-ovale-pfo/causes-and-diagnoses
When a baby is born and their lungs start to work, the pressure inside their heart normally causes the foramen ovale to close. The patent foramen ovale may not close for a year or two after birth. In some cases, it never closes. This results in a PFO. […] It is not known what causes PFO. There are also no known risk factors.
#7 Patent Foramen Ovale (PFO) (for Parents) – Humana – Louisiana
https://kidshealth.org/HumanaLouisiana/en/parents/pfo.html?WT.ac=p-ra
A foramen ovale is normal until birth. […] The process that closes it after a baby is born usually isn’t completely done until a baby is at least several months old. Why the flap doesn’t seal in some people is unknown. […] PFOs that do not close are common, and found in 1 of every 4 adults. […] PFOs are more likely in newborns who have a congenital heart defect.
#8 Patent foramen ovale – Symptoms & causes – Mayo Clinic
https://www.mayoclinic.org/diseases-conditions/patent-foramen-ovale/symptoms-causes/syc-20353487
A patent foramen ovale (PFO) is a hole in the heart that didn’t close the way it should after birth. […] It’s unclear why the foramen ovale stays open in some people. Genetics may play a role. […] Most people with the condition never know they have it. A patent foramen ovale is often discovered during tests for other health problems. […] Some studies have found that patent foramen ovales (PFOs) are more common in people with unexplained strokes and migraines with aura. But more research is needed. Usually, there are other reasons for these conditions. It’s often just a coincidence a person also has a PFO.
#9 Patent Foramen Ovale (PFO): Symptoms & Causes | NewYork-Presbyterian
https://www.nyp.org/heart/congenital-heart-disease/patent-foramen-ovale-pfo
Patent foramen ovale (PFO) is a flap-like opening in the heart between the upper chambers. […] When the flap doesnt fully close, its called a patent foramen ovale (PFO). This occurs in about one in four people, with the vast majority having no symptoms or medical problems. […] The cause of why a patent foramen ovale stays open in some hearts and not others is unknown.
#10 Patent foramen ovale Information | Mount Sinai – New York
https://www.mountsinai.org/health-library/diseases-conditions/patent-foramen-ovale
Patent foramen ovale (PFO) is a hole between the left and right atria (upper chambers) of the heart. This hole exists in everyone before birth, but most often closes shortly after being born. PFO is what the hole is called when it fails to close naturally after a baby is born. […] The cause of a PFO is unknown. There are no known risk factors. It can be found along with other heart abnormalities such as atrial septal aneurysms or Chiari network.
#11 Patent foramen ovale: MedlinePlus Medical EncyclopediaLock
https://medlineplus.gov/ency/article/001113.htm
Patent foramen ovale (PFO) is a hole between the left and right atria (upper chambers) of the heart. This hole exists in everyone before birth, but most often closes shortly after being born. PFO is what the hole is called when it fails to close naturally after a baby is born. […] The cause of a PFO is unknown. There are no known risk factors. It can be found along with other heart abnormalities such as atrial septal aneurysms or Chiari network. […] The opening is supposed to close soon after birth, but sometimes it does not. In about 1 out of 4 people, the opening never closes. If it does not close, it is called a PFO.
#12 Patent Foramen Ovale (PFO) | Boston Children’s Hospital
https://www.childrenshospital.org/conditions/patent-foramen-ovale
A patent foramen ovale (PFO) is a hole in the wall that that separates the heartâs two upper chambers (atria). All babies have this opening (called a foramen ovale) before birth to allow blood to bypass the lungs. Shortly after birth, the tissue usually grows together and closes the hole. But in about 25 percent of people, the hole remains open (patent), resulting in a PFO. Many people have a PFO and never know it. […] It is not know why this opening doesnât close in some people, but itâs thought that heredity and genetics may play a role.
#13 Patent Foramen Ovale in Fetal Life, Infancy and Childhood
https://www.mdpi.com/2076-3271/8/3/25
A patent foramen ovale (PFO) is a common, incidental echocardiographic finding in otherwise healthy and asymptomatic infants and children. […] There are limited data on the underlying causes of a PFO, although there is some good evidence that genetic factors play a role. […] The importance of a PFO in some critical congenital heart defects (CHD), especially in neonates, is well recognized. […] However, there is controversy regarding the clinical significance of a PFO with vascular events, specifically when accompanied by anatomic anomalies such as atrial septal aneurysms, Chiari networks and prominent Eustachian valves. […] The presence of a PFO has also been implicated in the pathogenesis of medical conditions such as platypnea-orthodeoxia syndrome, decompression sickness or migraine in children.
#14 Patent Foramen Ovale and Atrial Septal Defects | Iowa Heart Center
https://www.iowaheart.com/expert-resources/conditions-and-disorders/detail/?id=21
The foramen ovale is a small hole in the atrial septum that allows blood to flow between the atria in the fetus prior to birth. Normally, this foramen ovale closes at birth when increased blood pressure on the left side of the heart forces the opening to close. If it does not close, it is called a patent foramen ovale (PFO). […] A patent foramen ovale is fairly common in the general population at about 25% of people. Even though they are fairly common, only a small percentage of these people are at risk for stroke of unknown cause. In people who have had a stroke of unknown cause, the prevalence of PFO increases to 40% of that population. […] A PFO can be associated with an atrial septal aneurysm. This is characterized by increased mobility of the atrial septal wall.
#15 Patent Foramen Ovale | The Texas Heart InstituteÂ®
https://www.texasheart.org/heart-health/heart-information-center/topics/patent-foramen-ovale/
The foramen ovale lets blood flow directly from the right atrium to the left atrium during fetal development. The foramen ovale is an important part of the fetal circulatory system before birth, but it is supposed to close soon after birth. […] The word âpatentâ means unobstructed, or open. So, patent foramen ovale (PFO) means that the foramen ovale stays open after birth. About 1 out of every 3 or 4 people has PFO. There are no risk factors for PFO, but we do know that when babies are born with congenital heart disease, it is common for their foramen ovale to stay open. […] Unless there are other heart defects, PFO usually does not cause any problems. However, some studies have shown that if you have a PFO, you may have an increased risk of stroke. […] A stroke may also be more likely in people with PFOs if they also have an atrial septal aneurysm. […] Older people with PFOs may have an increased risk of heart attack for the same reason they may have an increased risk of stroke. […] Some studies have linked PFOs with migraines and some PFO patients have found that their migraine headaches go away after the PFO is closed.
#16 Patent Foramen Ovale | UMass Memorial Health
https://www.ummhealth.org/health-library/patent-foramen-ovale
A patent foramen ovale (PFO) is a small hole between the two upper chambers of the heart, the right and the left atrium. […] The condition is most important because it raises the risk of stroke. PFO’s don’t cause strokes. Blood clots can travel from the right atrium to the left atrium and out to blood vessels of the body. If the clot blocks a blood vessel in the brain, it can cause a stroke. […] Healthcare providers don’t know what causes the hole to stay open (patent) in some people instead of closing up. […] Sometimes a PFO occurs along with other heart problems. One such condition is Ebstein anomaly. […] A PFO is more likely to be involved in a stroke of a younger adult. That’s because younger people don’t have as many risk factors for stroke from other causes. […] Most strokes don’t result from a PFO. Even people who have a PFO often have strokes for other reasons. […] A PFO can cause other complications as well. These include:
#17 Patent Foramen Ovale (PFO) | Tampa General Hospital
https://www.tgh.org/institutes-and-services/conditions/patent-foramen-ovale-pfo
A patent foramen ovale develops when a naturally present hole in the heart fails to close after birth. […] In most cases, the exact cause of a patent foramen ovale is unknown. Rarely, a PFO may be related to other heart defects, such as Ebsteins anomaly, or genetic factors. […] Complications from PFO are generally considered uncommon, and the link between PFO and these conditions is still a topic of debate in the medical community.
#18 Patent Foramen Ovale (PFO) â Kidshealth | Akron Children’s
https://www.akronchildrens.org/kidshealth/en/parents/pfo.html
The process that closes it after a baby is born usually isn’t completely done until a baby is at least several months old. Why the flap doesn’t seal in some people is unknown. […] PFOs that do not close are common, and found in 1 of every 4 adults. PFOs are more likely in newborns who have a congenital heart defect.
#19 Patent Foramen Ovale Symptoms and Treatment | Dr. C Raghu
https://drraghu.com/resources/heart-and-brain-connection/patent-foramen-ovale/
Patent Foramen Ovale (PFO) is a hole in the heart that can be congenital or acquired. The foramen ovale is a flap-like opening between the heartâs upper chambers. It usually closes within three to six months after birth and becomes a part of your heartâs septum. […] In most cases, a PFO is present at birth (congenital). However, one can also develop it as an adult due to injury, infection, or inflammation of the tissue around the heart (acquired). […] PFO can also be the underlying cause of other conditions, such as: Hypoxemia (low blood oxygen), Pulmonary hypertension, Paradoxical embolism, Migraine, Atrial Fibrillation.
#20 Patent foramen ovale | Radiology Reference Article | Radiopaedia.org
https://radiopaedia.org/articles/patent-foramen-ovale?lang=us
A patent foramen ovale (PFO) is a normal fetal interatrial connection which can persist into adult life. This can cause stroke due to paradoxical embolus. […] Patent foramen ovale can be an etiological factor in acute ischemic stroke (cryptogenic stroke), consider PFO in younger populations without conventional historical risk factors. […] The ultimate diagnosis of patent foramen ovale is at autopsy by testing for probe patency. One study found that 34% of adults had PFO by this measure. […] Long-term elevation of right atrial pressure increases the patency rate. […] The majority do not cause clinical disease.
#21 Patent foramen ovale: indications for closure and techniques | EuroIntervention
https://eurointervention.pcronline.com/article/patent-foramen-ovale-indications-for-closure-and-techniques
Non-surgical closure of the patent foramen ovale (PFO) has been possible for 40 years and proved safe in probably a million cases performed worldwide. […] The presence of a patent foramen ovale (PFO) represents a distinctive cause of stroke with a similar causal relationship to other accepted aetiologies of stroke (e.g., atrial fibrillation, stenosis of the carotid artery). […] The most frequent cause of paradoxical embolism through a PFO is the migration of a thrombus originating from the deep venous circulation of the lower body half. […] Despite the presence of a PFO in about 20%-25% of the population, an association between the presence of a PFO and stroke is proven not only in younger, but also in older patients. […] Paradoxical embolism due to PFO may be associated with detrimental and potentially lethal complications other than stroke, such as myocardial infarction and peripheral embolic events, and the presence of PFO has been demonstrated to be an independent predictor of death and adverse outcome in patients with major pulmonary embolism.
#22 Patent Foramen Ovale Symptoms | Stroke Risk Reduction
https://www.structuralheart.abbott/patients/stroke-risk-reduction/atrial-fibrillation-pfo
During development, prior to birth, a channel between the right and left sides of the heart called the foramen ovale, allows blood from veins to bypass the lungs. In about 25% of people, the foramen ovale does not close completely after birth. When the foramen ovale remains open, it is called a patent foramen ovale or a PFO. […] One possible factor that may have contributed to a stroke of unknown cause is the presence of a patent foramen ovale. […] Blood clots in veins can develop for various reasons and travel to the right side of the heart. Normally, they are then pumped to the lungs, which act as a filter. However, a PFO can allow those clots to bypass the lungs and cross to the left side of the heart. From there, they can be pumped to the brain, causing a stroke. […] People who have a PFO and have had an embolic stroke of unknown cause may be at an increased risk for having a second stroke. In some people, a second stroke can be prevented by having the PFO closed. […] If you or a loved one has been diagnosed with a patent foramen ovale (PFO), its important to seek timely treatment since the condition increases the risk for stroke.
#23 Patent Foramen Ovale: symptoms, diagnosis, and complications
https://www.webmd.com/heart-disease/what-to-know-symptoms-pfo-patent-foramen-ovale
A patent foramen ovale is an opening that some adults have between the top two chambers of their hearts. […] Researchers do not currently understand why some close and others dont. […] The cause is unknown, but genetics could play a role. […] Most of the time, PFO is symptomless in adults, but there are some rare complications that are associated with the condition. […] There is no understood link between PFO and migraines, but adults with PFOs sometimes have an increased chance of having migraines particularly ones where halos form in your vision. […] People with this kind of stroke are two times more likely to have a PFO than the general population. […] In these cases, its likely a thromboembolic stroke, where a blood clot that forms elsewhere in your body such as your leg moves into your heart and through the PFO.
#24 Patent Foramen Ovale: Practice Essentials, Background, Pathophysiology
https://emedicine.medscape.com/article/156863-overview
Patent foramen ovale (PFO) is a flaplike opening between the atrial septa primum and secundum at the location of the fossa ovalis that persists after age 1 year. […] With increasing evidence that PFO is the culprit in paradoxical embolic events, the relative importance of the anomaly is being reevaluated. […] Patent foramen ovale (PFO) is an anatomic interatrial communication with potential for right-to-left shunt. […] James Lock, MD, postulated that PFO anatomy results in a cul-de-sac between the septa primum and secundum, predisposing individuals to hemostasis and clot formation. […] Any conditions that increase right atrial pressure more than left atrial pressure can induce paradoxical flow and may result in an embolic event. […] This reasoning has greatly altered the previous conception of PFO and has changed management of the condition.
#25 Patent Foramen Ovale and Stroke: Causes, Risks, and Treatment
https://www.londoncardiovascularclinic.co.uk/blog/patent-foramen-ovale-and-stroke-28103.html
A patent foramen ovale (PFO) can contribute to a stroke through a process called paradoxical embolism. […] Certain factors, such as an atrial septal aneurysm (ASA), can influence how PFO cause stroke. […] Other risk factors may include situations that raise pressure in the right side of the heart, such as straining during activities like coughing, sneezing, or heavy lifting. […] A patent foramen ovale (PFO) is a small opening in the heart that can increase the risk of stroke by allowing blood clots or air bubbles to bypass the lungs and travel to the brain. […] This connection between patent foramen ovale and stroke is particularly significant in cryptogenic strokes, especially when other risk factors are present. […] While not everyone with a PFO requires treatment, PFO closure can be an effective option for reducing stroke recurrence in selected patients.
#26 Patent Foramen Ovale (PFO) | SCAI – Seconds Count
https://www.secondscount.org/condition/patent-foramen-ovale-pfo
A patent foramen ovale (PFO) is essentially a hole in the heart. […] Theres no definitive cause for why it happens, although some researchers believe genetics may play a role. […] However, in some cases, a PFO has been linked to other health issues, such as migraines and ischemic stroke. […] Studies have also found that some people with a PFO suffer a cryptogenic stroke. Without other identified factors, these strokes may be related to a PFO. […] In those with a PFO, minimal blood usually crosses freely between the right and left atria due to the small pressure difference between these two chambers. However, activities (lifting heavy weights, for example) or changes in the chest geometry (after surgery, for example) can lead to changes in the pressures inside the heart, leading to more blood passing from the right atrium to the left atrium through the PFO. […] However, any particles in the blood or any type of blood clot can pass through the PFO, move out of the heart, and travel to the brain, which may cause a stroke.
#27 Patent foramen ovale closure review: decades of research and the evolution of the evidence | The Egyptian Journal of Internal Medicine | Full Text
https://ejim.springeropen.com/articles/10.1186/s43162-021-00059-8
However, about half of those with cryptogenic strokes have residual shunt across a PFO and paradoxical embolism across the shunt can be a contributory factor. […] Various risk stratification methods have been developed to predict the risk of repeated strokes in people with PFOs, such as the Risk of Paradoxical Embolism (RoPE) score, which indicates an increased risk of stroke if the score is at least 4. […] Even in those with a high risk of recurrent stroke, as determined by the ROPE ranking, the average risk of recurrent stroke is very low, and it is difficult to predict those at elevated risk with certainty. […] The presence of a hypermobile septum primum or an atrial septal aneurysm in conjunction with PFO raises the likelihood of an initial stroke by fivefold. […] The trials have shown that the risk of cerebral ischaemic events is higher in the presence of atrial septal aneurysm or a large PFO with significant shunt.
#28 Every Patent Foramen Ovale Should Be Closed
https://www.mdpi.com/2077-0383/13/11/3355
At present, the patent foramen ovale (PFO) does not receive the deserved medical attention. The PFO poses a serious threat to health and even the life of mankind. The fact that a PFO is present in roughly 25% of people underscores its overall potential to cause harm. About 5% of the population have particularly dangerous forms of PFOs. Such PFOs portray a high enough risk for clinical events, the likes of death, stroke, myocardial infarction, or ocular, visceral, and peripheral embolism, to justify screening for them. […] PFOs direly need to receive the medical attention they deserve. PFO closure effectively addresses potentially life-threatening problems with an intervention comparable, in intricacy, to mending teeth. A PFO exists in perhaps 25% of the population, with its particularly dangerous forms in presumably 5%. Screening for and closure of the PFO as primary prevention appears advantageous and cost-effective in at least the latter group.
#29 Patent foramen ovale – PubMed
https://pubmed.ncbi.nlm.nih.gov/27188965/
Patent foramen ovale (PFO) is the most common congenital heart abnormality of fetal origin and is present in approximately 25% of the worldwide adult population. PFO is the consequence of failed closure of the foramen ovale, a normal structure that exists in the fetus to direct blood flow directly from the right to the left atrium, bypassing the pulmonary circulation. […] PFO has historically been associated with an increased risk of stroke, the mechanism of which has been attributed to the paradoxical embolism of venous thrombi that shunt through the PFO directly to the left atrium. […] However, several studies have failed to show an increased risk of stroke in asymptomatic patients with a PFO, and the risk of stroke recurrence is low in patients who have had a stroke that may be attributed to a PFO. […] Considerable controversy remains regarding the optimal treatment strategy for patients with both cryptogenic stroke and PFO.
#30 Patent Foramen Ovale – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK493151/
Data in 1988 revealed that 30% to 40% of young patients who had a Cryptogenic stroke had a PFO. […] PFO primarily increases the risk of stroke from a paradoxical embolism. […] The majority of patients with PFO are asymptomatic. However, some may present with severe clinical symptoms like migraines-like headaches, symptoms, and signs of ischemic brain stroke or a transient ischemic event to any of the vital organs (brain, limb, kidneys, intestine, etc). […] PFO does not require treatment or follow-up in neonates and the pediatric population. PFO is vital in some congenital heart conditions dependent on blood shunting at the atrial level. […] In adults, treatment for PFO is mainly indicated in a patient with cryptogenic strokes. […] The management of patent foramen ovale is made by an interprofessional team that consists of a pediatrician, cardiologist, interventional radiologist, and a cardiac surgeon.
#31 Patent Foramen Ovale | Cedars-Sinai
https://www.cedars-sinai.org/health-library/diseases-and-conditions/p/patent-foramen-ovale.html
A patent foramen ovale (PFO) is a small opening between the two upper chambers of the heart, the right and the left atrium. […] The condition is most important because it raises the risk of stroke. PFO’s don’t cause strokes. […] Everyone has a PFO at birth. It is a normal part of the circulation of a baby in the uterus. […] But in some cases, it does not. Having a PFO as an adult or older child is not normal. […] Healthcare providers don’t know what causes the hole to stay open (patent) in some people instead of closing up. […] Sometimes a PFO occurs along with other heart problems. […] A PFO is more likely to be involved in a stroke of a younger adult. […] Most strokes don’t result from a PFO. […] A PFO can cause other complications as well.
#33 Patent foramen ovale closure review: decades of research and the evolution of the evidence | The Egyptian Journal of Internal Medicine | Full Text
https://ejim.springeropen.com/articles/10.1186/s43162-021-00059-8
However, device closure is not without its risks. […] In both the CLOSE trial and GORE-REDUCE trial, there was increased risk of device complications and AF following PFO closure. […] The occurrence of a PFO in middle-aged people with traditional cardiovascular risk factors or minor subcortical infarcts does not mean that the PFO is a causal factor for the stroke. […] The RoPE score is a valuable tool for predicting the role of a PFO in stroke risk in such individuals. […] The development of this score is based on data of more than 3600 patients with cryptogenic stroke who had transoesophageal echocardiography or transcranial Doppler confirmed PFO. […] A high score indicates a high possibility of the index stroke being caused by a PFO. […] The recent trials which showed the benefit of PFO closure developed inclusion criteria that made it possible to recruit a significant proportion of participants with adverse PFO anatomy.
#34 Patent foramen ovale closure review: decades of research and the evolution of the evidence | The Egyptian Journal of Internal Medicine | Full Text
https://ejim.springeropen.com/articles/10.1186/s43162-021-00059-8
A quarter of the population suffers from patent foramen ovale, a form of interatrial shunt. […] Its association with cryptogenic strokes has sparked interest in PFO closure. […] PFO remains the commonest association of cryptogenic stroke in young adults with up to half of cryptogenic strokes occurring in those with PFO. […] The cause usually is undetermined because the event is transitory or reversible, investigations did not look for all causes or because some causes are truly unknown. […] PFO-related stroke is defined as a separate group of patients in the European position paper on PFO where a PFO is believed to be involved in the genesis of cerebral ischaemic events. […] The prospective association of PFO with stroke risk is inconsistent since about a third of PFO in the setting of a stroke are incidental.
#35 Patent foramen ovale: indications for closure and techniques | EuroIntervention
https://eurointervention.pcronline.com/article/patent-foramen-ovale-indications-for-closure-and-techniques
In addition, several studies have observed a higher prevalence of PFO in patients suffering from migraine, particularly in patients with aura. […] Suggested hypotheses are paradoxical microembolism, which may act as a potential trigger for migraine attacks, and right-to-left shunting of neurotransmitters such as serotonin gushes not neutralised in the lungs, hence triggering a particular sensor in the brain. […] PFO closure should also be considered for primary prevention in patients at high risk of paradoxical embolism due to the tendency for venous thrombosis, vocational or recreational activities fostering right to left shunts, in the presence of high-risk PFO, or those who can expect a collateral benefit (e.g., patients suffering from migraine, sleep apnoea, etc.).
#36 Patent Foramen Ovale and Migraines: A Controversial Link
https://www.verywellhealth.com/migraine-and-patent-foramen-ovale-1719922
Some scientific studies have suggested a link between migraine with aura and a patent foramen ovale (PFO), a relatively common congenital heart defect. […] In terms of the reason for this relationship, some experts have suggested that it’s due (at least in part) to the mixing of oxygenated and non-oxygenated blood in the heart. Others have hypothesized that tiny clots pass from the right side of the heart to the left through the foramen ovale and that these tiny clots travel to the brain where they trigger migraine attacks. […] Many experts argue that studies showing a link between PFO and migraine were not adequately designed and that there is no good quality scientific proof that this link even exists. […] Others argue that the evidence is mixed, but that there’s more evidence to support an association between PFO and migraine with aura than there is to disprove it.
#37 Patent Foramen Ovale in Fetal Life, Infancy and Childhood
https://www.mdpi.com/2076-3271/8/3/25
There is a lack of scientific evidence for the need to close PFOs or the use of antiplatelets or anticoagulants in asymptomatic children. […] The treatment of PFOs in patients with associated clinical syndromes is discussed under each specific condition. […] A PFO could be a risk factor for stroke in children with sickle cell anemia because they are predisposed to thrombosis and elevations of right heart pressure, which could promote paradoxical embolization. […] The mechanism by which PFO may promote migraine remains speculative. […] The association between PFO and decompression illness suffered by divers and high-altitude pilots who rapidly transition from high- to low-pressure environments has been documented. […] Paradoxical systemic embolism through PFOs resulting in renal and myocardial infarctions have been reported.
#38 Patent Foramen Ovale (PFO) Closure: Procedure & Indications
https://www.icrjournal.com/articles/patent-foramen-ovale-closure-state-art?language_content_entity=en
A right-to-left shunt, such as a PFO, allows nitrogen bubbles to bypass the pulmonary filter, increasing the risk that usually safe ascents will cause systemic embolisation. […] A recent study noted that in a cohort of 59 divers with decompression illness and PFO closure, four continued to have decompression illness over the 10-year follow-up period. […] The indications are similar to those for cryptogenic stroke. […] The evidence for PFO closure is not strong enough to offer a routine recommendation for PFO closure in migraine with aura.
#39 Patent Foramen Ovale: symptoms, diagnosis, and complications
https://www.webmd.com/heart-disease/what-to-know-symptoms-pfo-patent-foramen-ovale
This complication is unique to scuba divers. […] Sometimes, though, this sickness is more spontaneous, seemingly uncaused by what the diver did. […] Most of the time, a patent foramen ovale doesnt need to be treated. […] Complications from this surgery are very unlikelyless than 1%but can include tears to the heart or blood vessels.
#40 Patent Foramen Ovale
https://mydoctor.kaiserpermanente.org/mas/structured-content/Condition_Patent_Foramen_Ovale_-_CV_Surgery.xml?co=/regions/mas
Patent foramen ovale (PFO) is a small hole in the heart that didnât close properly after birth. It affects about 1 in 4 people. Most donât know they have the condition because it rarely causes problems. […] Itâs not clear what causes PFO. Genetic factors may play a role. The condition is congenital, meaning the defect is present at birth. Viral infections can sometimes cause congenital heart defects. […] Unless other heart defects are also present, a PFO typically doesnât cause complications. However, some research has linked the following conditions to PFO. […] PFO may also be linked to hypoxemia (low blood oxygen), high-altitude sickness, and obstructive sleep apnea. Other factors play a role as well. For example, high blood pressure is the leading cause of stroke.
#41 Patent foramen ovale as a cause of fatigue – DoctorMyhill
https://www.drmyhill.co.uk/wiki/Patent_foramen_ovale_as_a_cause_of_fatigue
A Patent Foramen Ovale (PFO) therefore is a disease amplifying problem – it explains why some CFS/ME sufferers get a lot worse with a relatively minor exertion, i.e. the degree of worsening is not commensurate with the effort. […] One possible cause is a patent foramen ovale. […] In chronic fatigue syndrome 90% of patients have a patent foramen ovale. […] However this only becomes a problem in low cardiac output states. […] PFO is known to be a cause of migraine, cryptogenic stroke (ie when the cause is unknown), decompression sickness, possibly obstructive sleep apnoea (because during this there is a valsalva like pressures when the sufferer attempts to breath against a closed glottis) and, Cheney reckons, 100% of CFSs/PWME. […] Cheney has shown that in some patients if the proportion of oxygen in air is increased from 21% to 28% this causes closure of the PFO, presumably because the heart can increase its output when there is more oxygen.
#42 Every Patent Foramen Ovale Should Be Closed
https://www.mdpi.com/2077-0383/13/11/3355
The common myth that a PFO is only to be looked for in otherwise healthy and young patients with suspicion of paradoxical embolism must be laid to rest once and for all: the sicker and older the patient, the higher the prevalence of venous thrombosis and, thus, the higher the absolute probability that the PFO causes an embolic event. Along these lines, PFO-related embolic MIs are much more common than currently suspected, let alone diagnosed, especially in old and sick people. For every three emboli finding the brain, one will find a coronary artery based on the physiological systemic blood distribution.