Atrial fibrillation is the most common heart rhythm disorder and significantly increases the risk of stroke. When it is persistent, a simple electrocardiogram is sufficient to identify it. But the paroxysmal atrial fibrillation, which occurs in short, unpredictable episodes, presents a completely different challenge: between episodes, the heart appears perfectly normal. This article explains why it often goes unnoticed, what warning signs to look for, and what modern options are available for detecting it.
On this page
- Understanding Paroxysmal Atrial Fibrillation
- What symptoms might indicate this condition?
- Why Traditional Exams Can Fail
- The Consequences of a Missed Diagnosis
- Modern Approaches to Detecting Intermittent Arrhythmias
- What should you do if you suspect intermittent episodes?
- Myths and misconceptions
- Frequently asked questions
Understanding Paroxysmal Atrial Fibrillation
In a healthy heart, contractions are coordinated by a regular electrical signal that originates in the atria. In the case of atrial fibrillation, this the signal becomes chaotic : The atria no longer contract effectively, the rhythm becomes irregular, and blood can pool, promoting clot formation.
What characterizes the paroxysmal form
- Episodes that occur suddenly.
- A duration of a few seconds, minutes, or hours.
- A spontaneous resolution, without medical intervention.
- A return at unpredictable intervals, sometimes days or weeks apart.
Between episodes, the heart rate is perfectly normal. It is precisely this intermittent nature that makes the condition so difficult to diagnose.
To remember
- Atrial fibrillation is the most common arrhythmia.
- It increases the risk of stroke.
- The paroxysmal form occurs in short episodes.
- These episodes go away on their own.
- Between seizures, things seem to be back to normal.
- This intermittent nature makes diagnosis very difficult.
What symptoms might indicate this condition?
Some people don't feel no symptoms : Silent atrial fibrillation is more common than is generally believed. Others describe a variety of symptoms, which are often fleeting.
The most commonly reported symptoms
- Sudden palpitations, sometimes rapid and irregular.
- A sensation that the heart is «skipping a beat» or «beating in the throat.».
- Unusual fatigue after moderate exertion.
- Shortness of breath during activities that are usually easy.
- Dizziness or a lightheaded feeling.
- Mild chest pain or discomfort.
These symptoms are not specific to atrial fibrillation and may be indicative of other conditions, whether cardiac or not. However, their intermittent nature—spontaneous onset and resolution—should raise concern.
To remember
- Fibrillation can be completely silent.
- Sudden heart palpitations are a common symptom.
- Unusual fatigue and shortness of breath are also factors.
- Dizziness warrants attention.
- These symptoms are nonspecific.
- Their intermittent nature is the most telling sign.
Why Traditional Exams Can Fail
A resting electrocardiogram is a one-time review : It records the heart's activity for a few seconds. If you are not in fibrillation at that exact moment, the trace will be normal.
The Limitations of Short-Term Holter Monitoring
The 24-hour Holter monitor, which records the heart rhythm over a full day, increases the chances of detecting paroxysmal fibrillation, but is still insufficient if episodes occur only once a week or once a month. Statistically, a short-term Holter monitor has a limited chance of capturing a rare episode. This explains why so many patients experience recurrent palpitations, undergo multiple ECGs and Holter monitors, and receive the same answer each time: their test results are normal.
| Review | Observation Period | Ability to detect rare fibrillation |
|---|---|---|
| Resting ECG | A few seconds | Very low if not during an episode |
| 24-48-hour Holter monitor | 1 to 2 days | Limited for episodes that are spaced apart |
| Extended Monitoring | Several days to weeks | Significantly superior |
Do you have intermittent symptoms that aren't picked up by brief exams? Our teams can assess whether long-term monitoring is appropriate. Learn more about our services, explore our solutions for businesses, choose the teleconsultation or Make an appointment online.
The Consequences of a Missed Diagnosis
Undiagnosed atrial fibrillation is not harmless. Even brief episodes increase the risk of stroke, particularly so-called cryptogenic strokes, the cause of which remains unexplained after the usual investigations.
The Benefits of an Early Diagnosis
- Assess the risk of thromboembolism, or the tendency to form blood clots.
- Discuss the possibility of prophylactic anticoagulation.
- Refer the patient to appropriate cardiac care.
- Consider treatments to control the rhythm or rate.
Documenting arrhythmia, therefore, paves the way for preventive decisions that can change the course of a patient’s care. These treatment decisions are always made by the physician.
Modern Approaches to Detecting Intermittent Arrhythmias
Several diagnostic options have emerged to better detect intermittent arrhythmias, centered around a common principle : Extend the recording period well beyond the time frame of a standard Holter monitor.
Smart clothing with textile sensors
Among these approaches, smart clothing with textile sensors represents a significant advance. Instead of a wearable device with adhesive electrodes, users wear clothing with ECG sensors woven directly into the fabric. The comfort of this design allows for extended use—during sleep, exercise, and daily activities—without irritation or bulk.
SKIIN™ Technology at Our Service Locations
At our service locations in Quebec, we offer SKIIN™ technology in partnership with Myant Health, a Canadian company. This smart garment is approved by Health Canada as a Class II medical device and enables continuous cardiac monitoring over an extended period. The recordings are interpreted by a cardiologist, and a report is sent to the patient’s primary care physician. The main advantage is a higher likelihood of detecting an episode of paroxysmal atrial fibrillation compared to a short-term test.
What should you do if you suspect intermittent episodes?
If you experience occasional palpitations, dizziness, or shortness of breath, a structured approach helps move the diagnosis forward.
- See a doctor—whether it's a family doctor or a cardiologist.
- Describe the symptoms in detail: circumstances, duration, frequency, and triggers.
- Mention any family history of heart disease or stroke.
- Ask whether extended monitoring would be appropriate when the initial tests are normal.
At our service locations in Quebec, the evaluation may begin with an in-person or telemedicine consultation. The doctor will then refer the patient for the appropriate tests.
Myths and misconceptions
«If my ECG is normal, I don't have atrial fibrillation.»
False. An ECG only captures the moment it is recording. Paroxysmal fibrillation may be completely absent during the test and occur at other times.
«Atrial fibrillation always causes symptoms.»
False. The asymptomatic form is common. Some people experience no symptoms, which makes early detection even more important for those at high risk.
«Minor incidents are inconsequential.»
False. Even brief episodes can increase the risk of a stroke. That is why it is important to recognize and evaluate them, even if they seem harmless.
«A 24-hour Holter monitor is always enough to make a definitive diagnosis.»
Nuanced. The Holter monitor is useful, but its short duration limits its ability to detect a rare episode. Long-term monitoring is sometimes necessary to reach a conclusion.
«If we don't find anything, it's better to give up.»
False. Normal test results do not rule out the condition. When clinical suspicion persists, longer-term monitoring may ultimately confirm the arrhythmia.
Frequently asked questions
What distinguishes paroxysmal atrial fibrillation from the persistent form?
The paroxysmal form occurs in short episodes that resolve spontaneously, whereas the persistent form continues over time. Between paroxysmal episodes, the rhythm is normal, which complicates the diagnosis.
Is it possible to have atrial fibrillation without feeling it?
Yes. Silent atrial fibrillation—which has no noticeable symptoms—is more common than people realize. That is one of the reasons why screening high-risk individuals is important.
Why are my ECGs and Holter monitors always normal?
Because these tests cover a short period of time. If your episodes are infrequent, they may occur entirely outside the recording window. Extended monitoring increases the chances of capturing them.
How do smart clothes help?
It allows for continuous monitoring over an extended period under real-life conditions. This increases the likelihood of documenting an episode of paroxysmal fibrillation, with the analysis performed by a cardiologist.
Why is it important to diagnose this arrhythmia?
Because it increases the risk of stroke. A diagnosis makes it possible to assess this risk, discuss appropriate preventive measures, and refer the patient to the appropriate cardiology care, based on the doctor’s decision.
What should you do if you have severe symptoms?
If you experience chest pain, loss of consciousness, or any other serious symptoms, call 911 or go to the emergency room immediately. No amount of monitoring can replace emergency care.
Sources
- Heart + Stroke — Atrial Fibrillation: Understanding and Taking Action (coeuretavc.ca)
- National Institute of Excellence in Health and Social Services (INESSS) — Cardiology and Arrhythmias (inesss.qc.ca)
- Health Canada — Database of Licensed Medical Devices (canada.ca/sante-canada)
- Montreal Heart Institute — Patient Information (icm-mhi.org)
- Quebec Ministry of Health and Social Services (MSSS) (msss.gouv.qc.ca)
- Quebec College of Physicians (CMQ) — Professional Information (cmq.org)
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