---
title: Spontaneous coronary artery dissection
description: What spontaneous coronary artery dissection (SCAD) is, that it happens more often in women, including during pregnancy and after childbirth, how it differs from an ordinary heart attack, how it is recognised and treated, and when to call an ambulance.
type: disease
aliases:
  - SCAD
  - coronary artery dissection
  - spontaneous coronary dissection
sources:
  - tier: guideline
    org: minzdrav-rf
    title: Острый коронарный синдром без подъема сегмента ST электрокардиограммы
    year: 2024
    doi: 10.15829/1560-4071-2025-6319
    url: https://cr.minzdrav.gov.ru/view-cr/154_4
  - tier: guideline
    org: minzdrav-rf
    title: Острый инфаркт миокарда с подъемом сегмента ST электрокардиограммы
    year: 2024
    doi: 10.15829/1560-4071-2025-6306
    url: https://cr.minzdrav.gov.ru/view-cr/157_5
  - tier: guideline
    org: esc
    title: 2023 ESC Guidelines for the management of acute coronary syndromes
    year: 2023
    doi: 10.1093/eurheartj/ehad191
    url: https://doi.org/10.1093/eurheartj/ehad191
  - tier: review
    title: 'European Society of Cardiology, acute cardiovascular care association, SCAD study group: a position paper on spontaneous coronary artery dissection'
    year: 2018
    doi: 10.1093/eurheartj/ehy080
    url: https://doi.org/10.1093/eurheartj/ehy080
  - tier: review
    title: 'Spontaneous Coronary Artery Dissection: Current State of the Science: A Scientific Statement From the American Heart Association'
    year: 2018
    doi: 10.1161/CIR.0000000000000564
    url: https://doi.org/10.1161/CIR.0000000000000564
  - tier: reference
    org: msd-manuals
    title: Overview of Acute Coronary Syndromes (ACS)
    year: 2026
    url: https://www.msdmanuals.com/professional/cardiovascular-disorders/coronary-artery-disease/overview-of-acute-coronary-syndromes-acs
sources_checked: 2026-10-13
review: null
---

Spontaneous coronary artery dissection (SCAD) is a sudden splitting (dissection) of the wall of an artery that supplies the heart, not associated with atherosclerosis, trauma or a medical procedure.<Cite n={[1, 5]} /> Blood collects inside the artery wall, presses on the channel the blood flows through (the lumen), and less blood reaches the heart muscle.<Cite n={[4, 6]} /> This is why SCAD presents in the same way as an acute coronary syndrome, including a [heart attack (myocardial infarction)](../myocardial-infarction/).<Cite n={[1, 5]} /> It is an infrequent cause of acute coronary syndrome overall, but accounts for a significant proportion of cases in young and middle-aged women, and it is the most common cause of heart attack in pregnancy.<Cite n={3} />

<Diagram name="spontaneous-coronary-artery-dissection">
  <p slot="normal">
    The diagram shows a coronary artery cut across. The lumen is lined by the inner layer of the
    wall (the intima); deeper lies the middle layer (the media).<Cite n={[4, 5]} /> For comparison, the normal artery is drawn with a wide, open lumen.
  </p>
  <p slot="disease">
    In SCAD a second, "false" lumen filled with blood forms inside the artery wall: a haematoma in
    the wall.<Cite n={[4, 5]} /> It presses on the true lumen from outside and narrows it, and blood
    flow to the heart muscle falls.<Cite n={[4, 6]} /> The narrowing is caused not by a ruptured
    plaque or a blood clot, as in an ordinary heart attack, but by the haematoma in the wall or a
    tear in the inner layer.<Cite n={5} />
  </p>
</Diagram>

## Why it happens

<Patient>

In SCAD, blood gets inside the artery wall and spreads along it, forming a false lumen that squeezes the true one.<Cite n={[4, 6]} /> Exactly how it starts is not known: blood may enter the wall through a tear in the inner layer, or leak from a tiny vessel that supplies the wall itself.<Cite n={[4, 5]} />

This is not atherosclerosis, which is described in the article on [coronary heart disease](../coronary-heart-disease/). People with SCAD have fewer of the usual risk factors for a heart attack, and some have none at all; their other heart arteries are usually normal.<Cite n={[4, 5]} /> The vast majority of people affected are women.<Cite n={4} /> In pregnancy, SCAD happens mostly late in pregnancy and in the first weeks after childbirth, but only a small share of all cases are linked to pregnancy.<Cite n={[3, 4, 5]} />

SCAD often goes together with fibromuscular dysplasia, a non-inflammatory disease of the artery wall that can narrow or tear, for example, the kidney arteries and the arteries of the neck and head.<Cite n={4} /> The triggers reported most often before SCAD are extreme physical or emotional stress; very hard straining can also bring it on.<Cite n={[4, 5]} />

</Patient>

<Student>

The Russian Ministry of Health guideline defines SCAD as a non-atherosclerotic lesion of a coronary artery with separation of the intima, formation of a subintimal haematoma and obstruction of the lumen, of spontaneous (non-iatrogenic) origin.<Cite n={[1, 2]} /> The sources differ on where the haematoma lies: according to ESC-ACCA and the AHA, the false lumen generally forms in the outer third of the tunica media rather than beneath the intima; blood propagates axially and compresses the true lumen from outside.<Cite n={[4, 5]} /> The predominant mechanism of ischaemia is obstruction by the intramural haematoma or intimal disruption, rather than plaque rupture or intraluminal thrombus.<Cite n={5} />

Two models have been proposed: "inside-out" (an endothelial and intimal tear lets blood cross the internal elastic lamina into the media) and "outside-in" (primary disruption of a vasa vasorum microvessel with haemorrhage into the media); whether one of them dominates is unclear.<Cite n={[4, 5]} /> The pathophysiology of SCAD is different to that of type 1 MI; the Russian Ministry of Health guidelines classify MI due to spontaneous coronary dissection as type 2 MI.<Cite n={[1, 2, 3]} />

The most frequent association is fibromuscular dysplasia (FMD); inherited connective tissue disorders account for a small minority of cases.<Cite n={4} /> SCAD is not a strongly inherited condition; the AHA does not advise routine genetic testing in the absence of a suggestive history or physical examination, while ESC-ACCA calls for a thorough clinical assessment for rare connective tissue disorders in all survivors.<Cite n={[4, 5]} /> The link with pregnancy suggests a role for female sex hormones, but the mechanism remains unknown.<Cite n={4} />

</Student>

## Symptoms

<Patient>

The symptoms of SCAD are no different from those of an ordinary heart attack.<Cite n={1} /> Most often there is chest pain, which may spread to the arm and neck; there may also be nausea and vomiting, sweating, breathlessness and back pain.<Cite n={[4, 5]} /> Sometimes SCAD begins with a dangerous heart rhythm disturbance or sudden cardiac arrest.<Cite n={[4, 5]} />

People with SCAD are often young and have no risk factors, so a heart attack may not be suspected and they may be sent home; the diagnosis is often delayed.<Cite n={[4, 5]} />

</Patient>

<Student>

SCAD presents as ACS (ST-elevation or non-ST-elevation MI), less often as ventricular arrhythmias, sudden cardiac death or cardiogenic shock.<Cite n={5} /> ESC-ACCA advises that SCAD be actively considered in ACS presentations in low-risk patients.<Cite n={4} /> The differential diagnosis includes atherosclerotic ACS, coronary artery spasm, [takotsubo syndrome](../takotsubo-syndrome/), coronary thromboembolism and myocardial infarction with non-obstructive coronary arteries (MINOCA); ESC 2023 lists SCAD among the coronary causes of MINOCA.<Cite n={[3, 4]} />

</Student>

## How it is diagnosed

<Patient>

Tests begin in the same way as for any suspected heart attack.<Cite n={[1, 2]} /> The blood level of troponin is almost always raised, although the first test may be normal; there is no specific blood test for SCAD.<Cite n={[4, 5]} />

The main test is coronary angiography.<Cite n={[4, 5]} /> It shows the lumen of the artery but not the wall itself.<Cite n={5} /> Any heart artery can be affected, but most often it is the <Structure id="left-anterior-descending-artery">anterior interventricular (left anterior descending) branch of the left coronary artery</Structure>.<Cite n={5} /> If the diagnosis is unclear, the doctor may look at the wall from inside using intravascular ultrasound (IVUS) or optical coherence tomography (OCT).<Cite n={[1, 3]} /> But if SCAD is seen on angiography and the plan is treatment without a stent, no further instruments are passed into the artery, for safety reasons.<Cite n={3} />

After SCAD, doctors advise imaging other arteries, from the brain to the pelvis, to look for fibromuscular dysplasia, aneurysms and dissections.<Cite n={[4, 5]} />

</Patient>

<Student>

The Russian Ministry of Health guideline describes three angiographic types: 1, multiple visible lumens; 2, a long smooth narrowing due to an intramural haematoma; 3, a focal stenosis that looks like an atherosclerotic plaque.<Cite n={[1, 2]} /> According to the AHA, type 2 is the most common, and relying only on the classic double-lumen appearance would miss most cases.<Cite n={5} /> ESC-ACCA also describes type 4, a total occlusion, usually of a distal vessel.<Cite n={4} /> The mid to distal segments are most often affected, especially the anterior interventricular (left anterior descending) branch; multivessel SCAD occurs.<Cite n={5} />

Angiography is "lumenography": it does not image the arterial wall.<Cite n={5} /> The sources differ on the role of intravascular imaging. The Russian Ministry of Health guidelines call IVUS and OCT the most accurate methods for confirming SCAD.<Cite n={[1, 2]} /> ESC 2023 advises that they be carefully considered only in cases of diagnostic uncertainty, and does not recommend additional coronary instrumentation when the diagnosis is made on angiography and medical therapy is planned.<Cite n={3} />

</Student>

<HeartModel highlight={['left-anterior-descending-artery']} />

## How it is treated

<Patient>

SCAD is treated differently from a heart attack caused by plaque.<Cite n={[3, 5]} /> In most people the dissection first stabilises without a stent and then heals over a few months.<Cite n={[4, 5]} /> So if the person is stable and there are no signs of ongoing shortage of blood to the heart, treatment with medicines and observation is usually chosen rather than a stent.<Cite n={[2, 3, 5]} /> Placing a stent in a dissected artery is harder: the guidewire may enter the false lumen, and the balloon and stent may push the haematoma further along the artery.<Cite n={[4, 5]} /> A balloon or stent is needed only in special cases. Under the European guidelines, this applies only when the shortage of blood to the heart is ongoing, a large area of heart muscle is at risk and blood flow along the artery is reduced, all at the same time; the Russian guidelines list complete blockage of the artery, an unstable condition, an ongoing shortage of blood to the heart and a high risk of complications.<Cite n={[2, 3]} /> In some cases bypass surgery is needed.<Cite n={3} />

In the first days the dissection can extend, so even without a stent the person is monitored in hospital.<Cite n={5} /> The doctor chooses the medicines. Clot-dissolving treatment (thrombolysis) should not be used once SCAD has been confirmed; in a heart attack, the ambulance or hospital doctor chooses the treatment.<Cite n={4} />

The long-term outlook for survival is generally good, but the dissection can come back, usually in another, previously healthy artery; a stent placed the first time does not appear to protect against this.<Cite n={[4, 5]} /> Chest pain after SCAD is common and does not always mean a new dissection, but a doctor should assess any new pain.<Cite n={[4, 5]} /> Doctors advise considering cardiac rehabilitation; people return to normal life gradually, avoiding extreme, competitive and isometric (static strength) exercise and activities performed to exhaustion.<Cite n={[4, 5]} /> Anxiety and depression are common after SCAD, especially when it happened during pregnancy or after childbirth, and it is important to talk to a doctor about them.<Cite n={5} /> A pregnancy after SCAD is a high-risk pregnancy and is discussed in advance with doctors at a specialist centre.<Cite n={[4, 5]} /> Hormonal contraception and hormone therapy are avoided where possible; the method is chosen together with a doctor.<Cite n={[4, 5]} />

</Patient>

<Student>

Conservative management, as opposed to PCI, is generally recommended in SCAD; there are no randomised controlled trials comparing pharmacological strategies.<Cite n={[3, 4]} /> Until such evidence is available, ESC 2023 advises the same pharmacological therapy as for other ACS; the use and duration of antiplatelet therapy remain controversial, and for anticoagulants there is a theoretical concern about increasing bleeding into the haematoma.<Cite n={[3, 4, 5]} /> Thrombolysis is contraindicated in SCAD.<Cite n={4} /> Drugs and doses are not given here.

ESC 2023 (class I, level C): PCI only for patients with symptoms and signs of ongoing myocardial ischaemia, a large area of myocardium in jeopardy and reduced antegrade flow.<Cite n={3} /> With total (complete) occlusion, haemodynamic instability, persisting ischaemia and high risk, the Russian Ministry of Health guidelines recommend PCI (balloon dilatation and/or stenting in the STEMI guideline, stenting in the NSTE-ACS guideline) and note that endovascular strategies have not been defined.<Cite n={[1, 2]} /> CABG is recommended when the dissection affects the left main or two proximal vessels, if PCI is not feasible or unsuccessful and ischaemia is ongoing; the grafts later often occlude, probably because the native artery heals.<Cite n={[3, 5]} />

Recurrent SCAD means a new (de novo) dissection, usually in a previously unaffected artery; stenting at the first event does not appear to protect against it.<Cite n={[4, 5]} /> No treatment strategy has yet been shown to reduce recurrence; a known risk factor is severe coronary tortuosity.<Cite n={[4, 5]} />

</Student>

## When to call an ambulance

SCAD is an acute coronary syndrome, and if you notice its signs, call an ambulance straight away: call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK).<Cite n={[1, 2]} /> Call an ambulance if pressing pain or discomfort behind the breastbone does not go away at rest, spreads to the neck, lower jaw, left arm, below the left shoulder blade or to the upper abdomen, or if such sensations are new, have become more frequent or stronger, or come on at rest or with little exertion.<Cite n={[1, 2]} /> Do not put off the call even if you are young and have no risk factors, or are pregnant or have recently given birth: heart attacks happen in these cases too; SCAD is the most common cause of heart attack in pregnancy and after childbirth, and in young people without risk factors a heart attack is often not recognised straight away.<Cite n={[3, 4, 5]} /> This also applies to people who have already had SCAD: the dissection can come back, so with such pain they too should call an ambulance straight away.<Cite n={[1, 4]} /> More about the signs of a heart attack is in the article on [myocardial infarction](../myocardial-infarction/).

<Quiz />