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Chest pain often makes people think of one thing immediately: a blocked heart artery.
So when a patient undergoes coronary angiography and the report shows no major blockage, it can feel reassuring. But then comes the confusing part: the chest pain continues.
Does that mean the pain is not related to the heart?
Not necessarily.
Modern cardiology recognises that heart-related chest pain can occur even when the major coronary arteries appear normal or have only minor narrowing. Conditions involving the heart's smaller blood vessels, temporary artery spasms, and other functional problems can all produce genuine symptoms without a large fixed blockage being visible on conventional angiography.
Coronary angiography is primarily used to examine the major coronary arteries that supply blood to the heart muscle.
It can help doctors identify:
But angiography mainly provides an anatomical picture of the larger coronary arteries.
The coronary circulation also contains a network of very small vessels called the coronary microcirculation. Problems involving these vessels may not appear as a major blockage on a standard angiogram.
This is one reason why a "normal" or "non-obstructive" angiography result does not automatically explain every episode of chest pain.
One possible explanation is coronary microvascular dysfunction (CMD).
The heart contains tiny blood vessels responsible for regulating blood flow according to how much oxygen the heart muscle needs.
In some patients, these vessels may not widen appropriately during increased demand. As a result, the heart muscle may temporarily receive insufficient blood flow, potentially causing:
Because these vessels are extremely small, conventional angiography may not directly reveal the problem.
Current cardiovascular guidelines increasingly recognise microvascular dysfunction as an important cause of angina in patients without obstructive coronary artery disease.
Another possible cause is coronary artery spasm, also known as vasospastic angina.
Instead of having a permanently blocked artery, part of a coronary artery temporarily tightens or spasms.
During the spasm, blood flow to the heart muscle may decrease and cause chest pain.
The difficulty is that the artery may look relatively normal when angiography is performed if the spasm is not occurring at that particular moment.
Specialised coronary function testing may sometimes be used to investigate suspected vasospasm.
Doctors increasingly use the term INOCA, meaning Ischaemia with Non-Obstructive Coronary Arteries.
Ischaemia means that an area of the heart muscle is not receiving adequate blood flow for its needs.
INOCA may occur because of problems such as:
This isn't some obscure technical footnote either. The European Society of Cardiology reports that more than half of people suspected of having chronic coronary syndrome may have angina or ischaemia with non-obstructive coronary arteries.
The American Heart Association similarly notes that up to 50% of patients with angina can show non-obstructive coronary artery disease on angiography or coronary CT angiography.
"No major blockage" does not always mean "completely disease-free arteries."
A patient may have plaque or mild narrowing that does not obstruct enough of the artery to require a stent or other revascularisation procedure.
Non-obstructive coronary artery disease can still be clinically important and may require management of cardiovascular risk factors.
This distinction matters because patients sometimes hear "no blockage" and assume there is absolutely nothing wrong with their coronary circulation. Human anatomy, apparently unwilling to respect simple yes-or-no answers, is considerably more complicated.
Not every episode of chest pain is caused by coronary blood-flow problems.
Possible non-cardiac causes include:
Gastroesophageal reflux can cause burning or pressure behind the breastbone that may resemble cardiac pain.
Strained chest muscles, inflammation around the ribs, or injuries can cause pain that becomes worse with movement or pressure.
Certain respiratory conditions can cause chest discomfort, particularly when accompanied by coughing or difficulty breathing.
Stress and anxiety can produce genuine physical symptoms, including chest tightness, rapid heartbeat, sweating and shortness of breath.
However, persistent chest pain should not simply be labelled as "gas" or "stress" without appropriate medical evaluation.
The next step depends on the patient's symptoms, medical history, risk factors and previous investigation results.
Depending on the clinical situation, a cardiologist may consider additional evaluation such as:
For patients with persistent symptoms and suspected INOCA, specialised testing can help determine whether microvascular dysfunction or vasospasm is responsible.
The goal is not simply to keep repeating tests looking for a large blockage. It is to understand why the patient is experiencing chest pain and identify the underlying mechanism.
Treatment depends entirely on the cause.
When microvascular dysfunction or vasospasm is identified, doctors may use appropriate medications alongside management of cardiovascular risk factors and lifestyle changes. Treatment should be individualised because therapy that helps one mechanism may not be the best approach for another.
Blood pressure, cholesterol, diabetes, smoking, physical activity, sleep, weight and other cardiovascular risk factors may also need attention.
The important point is that absence of a major coronary blockage does not mean persistent symptoms should simply be ignored.
New, severe or rapidly worsening chest pain needs urgent medical attention, particularly when it occurs with symptoms such as:
Previous normal angiography should not be used as a reason to ignore new or severe symptoms.
For decades, conversations about coronary disease focused heavily on whether an artery was "blocked" or "not blocked."
That understanding is changing.
Current evidence recognises that abnormalities involving both the large coronary arteries and the heart's microcirculation can contribute to chronic coronary syndromes.
For patients, the takeaway is simple:
Persistent chest pain deserves an explanation, even when angiography shows no major blockage.
Understanding whether the symptoms come from microvascular dysfunction, coronary spasm, another cardiac condition or a non-cardiac cause can help doctors choose a more appropriate treatment strategy.
If you continue to experience chest discomfort despite angiography showing no significant coronary blockage, a detailed cardiovascular evaluation may help identify other possible causes.
At Oxymed Hospital, patients can consult with the medical team for further evaluation and an individualised approach based on their symptoms, medical history and previous test results.
This article is intended for general educational purposes and should not replace individual medical advice, diagnosis or emergency care.