A small opening between heart chambers can let a clot reach brain arteries and cause an ischemic stroke, most often with a PFO.
“Hole in the heart” is a catch-all phrase. It can mean a tiny flap that never sealed after birth, a true gap in the wall between chambers, or a leftover leak after a repair. Some findings are harmless. Others change blood flow, raise rhythm trouble, or create a route for a clot to reach the brain.
This article breaks down which “holes” matter for stroke, what doctors test for, and how treatment choices are usually made after a stroke workup.
Can A Hole In The Heart Cause A Stroke? What Doctors Mean By That
When clinicians connect a heart opening to stroke, they’re usually describing a path for a clot to cross from the right side of the heart to the left. From the left side, blood goes out to the body and the brain. A clot that takes this detour is called a paradoxical embolism.
The most common structure linked to this is a patent foramen ovale (PFO). Before birth, everyone has an opening between the top chambers. In most people it seals after birth. When it doesn’t, it’s called a PFO. MedlinePlus’ “Patent foramen ovale” entry describes it as a hole between the atria that failed to close.
Another term you may hear is atrial septal defect (ASD). Unlike a PFO, an ASD is a true gap in the atrial wall. Many ASDs push blood left-to-right, which is a different setup than a clot crossing right-to-left.
How A Heart Opening Can Lead To Stroke
Most ischemic strokes happen when a clot blocks blood flow in the brain. The clot can form in the heart, in a neck artery, or elsewhere and travel. A venous clot from the legs usually goes to the lungs first. The lungs often trap it.
With a right-to-left shunt, a clot can bypass the lungs and enter arterial blood. If it lodges in a brain artery, it can cause an ischemic stroke. The American Stroke Association notes that PFO is common and that most people with a PFO have no adverse effects. Its PFO overview also explains why the PFO-stroke link is mainly raised in selected patients.
Moments That Can Open The Flap
A PFO is a flap, so it tends to open when right-side pressure rises for a moment. That can happen with coughing, straining on the toilet, heavy lifting, or blowing hard against a closed mouth and nose. These brief spikes are why a bubble study may show crossover only when you strain.
Details On Imaging That Change The Call
On an echocardiogram, clinicians may describe the shunt size and whether crossover happens at rest or only with strain. They may also note an atrial septal aneurysm, a mobile segment of the septum that often travels with PFO. These features can raise concern that a PFO is part of the stroke story.
When A “Hole” Is Probably Not The Driver
A PFO or small defect can be an incidental finding, especially when another cause is clear. If long-term rhythm monitoring shows atrial fibrillation, that usually takes center stage. Severe carotid narrowing, a heart chamber clot, or a classic small-vessel pattern on brain imaging can also outweigh a PFO in the causal ranking.
Age matters too. PFO-related stroke is raised most often in younger and middle-aged adults with fewer traditional vascular issues. In older adults, strokes more often have other explanations, so a PFO can be a bystander.
How Clinicians Check For A Shunt And Competing Causes
Testing comes in layers because each test answers a different question: Is there a shunt? Is there a rhythm problem? Are the neck arteries healthy? Is there a clot source in the heart?
Echo With Or Without A Bubble Study
A transthoracic echocardiogram (TTE) is an ultrasound through the chest wall. It can include a bubble study using saline microbubbles. If bubbles appear on the left side within a few beats, it suggests a shunt.
A transesophageal echocardiogram (TEE) places a probe in the esophagus for sharper views. It can define PFO versus ASD more clearly and can check valves and chambers for clots.
Rhythm Monitoring
Atrial fibrillation can come and go with no symptoms. A short ECG can miss it. Longer monitoring with a patch, Holter, or an implantable loop recorder can catch it and change the medicine plan.
Brain And Vessel Imaging
CT or MRI shows stroke pattern and timing. CT angiography or MR angiography checks for artery narrowing or dissection. NINDS keeps a clear overview of stroke warning signs and treatment basics. The NINDS stroke page is a solid reference when you want a reliable summary.
| Finding | What It Means | Stroke Link In Plain Terms |
|---|---|---|
| Patent Foramen Ovale (PFO) | Flap between atria that didn’t seal after birth | Can let a venous clot cross to the left heart and reach the brain |
| PFO With Large Shunt | Many bubbles cross at rest or with light strain | More concern that the opening could be causal in embolic stroke |
| PFO With Atrial Septal Aneurysm | Mobile septum segment paired with PFO | May raise crossover odds in selected patients |
| Small ASD | True gap in atrial wall, often left-to-right flow | Stroke link is less direct unless bidirectional flow occurs |
| Large ASD | Can enlarge right heart and raise arrhythmia odds | Stroke can relate to rhythm issues more than clot crossover |
| Residual Shunt After Repair | Persistent small flow after closure surgery or device | May keep a crossover route if right-to-left flow occurs |
| VSD With Right-To-Left Shunt | Lower-chamber opening with reversed flow in late-stage cases | Clots can bypass lung filtering when shunt is right-to-left |
| Complex Cyanotic Congenital Heart Disease | Group of conditions with chronic right-to-left shunting | Higher embolic stroke odds because venous clots can reach arteries |
How Treatment Choices Are Usually Made
After an ischemic stroke, the first goal is to prevent another one. The plan depends on the most likely source of the first event and on the person’s bleeding risk, age, and anatomy.
Antiplatelet Therapy
Antiplatelet medicines like aspirin reduce platelet clumping. They are commonly used after many ischemic strokes when atrial fibrillation is not the cause.
Anticoagulation
Anticoagulants act on clotting proteins. They are standard for atrial fibrillation and for some clotting conditions. They also come with bleeding trade-offs, so the decision is personal.
PFO Closure For Selected Patients
PFO closure is done through a catheter, placing a device across the opening. It is not meant for everyone with a PFO. It is often weighed when a person has an embolic-appearing ischemic stroke, other causes have been reasonably excluded, and the PFO anatomy makes sense as a route.
The American Academy of Neurology has a practice advisory update on PFO closure for secondary stroke prevention that summarizes evidence and patient selection points. AAN’s PFO advisory is a good anchor for the “who benefits” call.
Closure can also carry procedure risks and can be followed by atrial fibrillation in some patients, which is why most teams weigh the full view before moving ahead.
| Test | What It Clarifies | Why It Matters |
|---|---|---|
| TTE | Heart structure and pumping function | Finds major heart disease and sets a baseline |
| Bubble Study | Right-to-left crossover at rest or with strain | Helps judge whether a shunt is present and how large it is |
| TEE | Septum detail and clot search | Separates PFO from ASD and checks valves and chambers closely |
| Long Rhythm Monitoring | Intermittent atrial fibrillation | Changes medicine choices and the closure conversation |
| CTA Or MRA | Neck and brain artery problems | Finds narrowing, dissection, or other vessel sources |
| Leg Vein Ultrasound | Deep vein thrombosis | Strengthens the paradoxical embolism story when positive |
Stroke Warning Signs That Need Emergency Action
Stroke symptoms can start suddenly. Call your local emergency number right away if you notice:
- Face drooping on one side
- Arm weakness or numbness on one side
- Speech trouble, slurred words, or trouble finding words
- Sudden vision loss, double vision, or severe balance trouble
- Sudden severe headache
Fast treatment can protect brain tissue. If you’re unsure, treat it as urgent.
Questions That Make Appointments More Useful
Bring these to neurology or cardiology visits, especially after a stroke workup:
- What stroke type did I have, and what did MRI or CT show?
- Did the pattern look embolic, like a traveling clot?
- How long was rhythm monitoring, and do I need longer monitoring?
- What did the bubble study show at rest and with strain?
- Do I have septum features like atrial septal aneurysm?
- Based on my profile, is the PFO likely causal or incidental?
- What medicine plan fits me, and what bleeding signs should prompt a call?
A One-Page Checklist For Your Records
Keeping one page of details can reduce confusion when you see different clinicians:
- Stroke date and type, plus the imaging report summary
- Echo results, including shunt size wording
- Rhythm monitoring dates and duration
- History of DVT or pulmonary embolism, if present
- Current medicines and start dates
- Next follow-up dates and which clinic owns each step
References & Sources
- MedlinePlus Medical Encyclopedia.“Patent foramen ovale.”Defines PFO and summarizes typical evaluation.
- American Stroke Association.“Patent Foramen Ovale (PFO).”Explains how common PFO is and when it can relate to stroke.
- National Institute of Neurological Disorders and Stroke (NINDS).“Stroke.”Overview of stroke warning signs, treatment, and prevention basics.
- American Academy of Neurology (AAN).“Practice advisory update: Patent foramen ovale and secondary stroke prevention.”Summarizes evidence and patient selection points for PFO closure after stroke.