Coronary artery dissection
Encyclopedia
A coronary artery dissection (also known as spontaneous coronary artery dissection, or SCAD) is a rare, sometimes fatal traumatic condition, with eighty percent of cases affecting women. The coronary artery develops a tear, causing blood to flow between the layers which forces them apart
. Early studies of the disease placed mortality rates at around 70%, but more recent evidence suggests a figure of around 20% The condition is often seen to be related to female hormone levels, as well as other pre-existing cardiovascular conditions. In addition to this, a dissection can occur iatrogenically
, by the surgical inserion of a catheter
into the coronary artery.
(heart attack), with the most common being persistent chest pain.
levels, as most cases appear to arise in pre-menopausal women, although there is evidence that the condition can have various triggers; other underlying conditions such as hypertension
may sometimes be causes. There is also a possibility that exercise can be a trigger. However cases sometimes have no obvious cause.
into the coronary artery.
. This allows blood to penetrate and cause an intramural hematoma
in the central layer, the tunica media
, and a restriction in the size of the lumen
, resulting in reduced blood flow which in turn causes myocardial infarction
and can later cause sudden cardiac death
.
is the most common method to diagnose the condition, although it is sometimes not recognised until after death. Intravascular ultrasound (IVUS) is also used as it is able to more easily differentiate the condition from atherosclerotic disease
.
is performed to redirect blood flow around the affected area. Drug-eluting stent
s and thrombolytic drug
therapy are less invasive options for less severe cases.
Dissection (medical)
In medical pathology, dissection refers to a tear within the wall of a blood vessel, which allows blood to separate the wall layers, creating a pseudoaneurysm.- Types :Examples include:*Aortic dissection...
. Early studies of the disease placed mortality rates at around 70%, but more recent evidence suggests a figure of around 20% The condition is often seen to be related to female hormone levels, as well as other pre-existing cardiovascular conditions. In addition to this, a dissection can occur iatrogenically
Iatrogenesis
Iatrogenesis, or an iatrogenic artifact is an inadvertent adverse effect or complication resulting from medical treatment or advice, including that of psychologists, therapists, pharmacists, nurses, physicians and dentists...
, by the surgical inserion of a catheter
Catheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
into the coronary artery.
Signs and symptoms
The symptoms are often very similar to those of myocardial infarctionMyocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
(heart attack), with the most common being persistent chest pain.
SCAD
There is evidence to suggest that a major cause of spontaneous coronary artery dissection (SCAD) is related to female hormoneHormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
levels, as most cases appear to arise in pre-menopausal women, although there is evidence that the condition can have various triggers; other underlying conditions such as hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
may sometimes be causes. There is also a possibility that exercise can be a trigger. However cases sometimes have no obvious cause.
Iatrogenesis
It has been recognised that some instances are iatrogenic, as it can be caused by the insertion of a catheterCatheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
into the coronary artery.
Pathophysiology
Coronary artery dissection results from a tear in the inner layer of the artery, the tunica intimaTunica intima
The tunica intima is the innermost layer of an artery or vein. It is made up of one layer of endothelial cells and is supported by an internal elastic lamina...
. This allows blood to penetrate and cause an intramural hematoma
Hematoma
A hematoma, or haematoma, is a localized collection of blood outside the blood vessels, usually in liquid form within the tissue. This distinguishes it from an ecchymosis, which is the spread of blood under the skin in a thin layer, commonly called a bruise...
in the central layer, the tunica media
Tunica media
The tunica media is the middle layer of an artery or vein.-Artery:It is made up of smooth muscle cells and elastic tissue...
, and a restriction in the size of the lumen
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
, resulting in reduced blood flow which in turn causes myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
and can later cause sudden cardiac death
Sudden Cardiac Death
Sudden cardiac death is natural death from cardiac causes, heralded by abrupt loss of consciousness within one hour of the onset of acute symptoms. Other forms of sudden death may be noncardiac in origin...
.
Diagnosis
A selective coronary angioplastyAngioplasty
Angioplasty is the technique of mechanically widening a narrowed or obstructed blood vessel, the latter typically being a result of atherosclerosis. An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed locations and then inflated to a fixed size...
is the most common method to diagnose the condition, although it is sometimes not recognised until after death. Intravascular ultrasound (IVUS) is also used as it is able to more easily differentiate the condition from atherosclerotic disease
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
.
Treatment
Treatment is varied depending upon the nature of the case. In severe cases, coronary artery bypass surgeryCoronary artery bypass surgery
Coronary artery bypass surgery, also coronary artery bypass graft surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease...
is performed to redirect blood flow around the affected area. Drug-eluting stent
Drug-eluting stent
A drug-eluting stent ' is a peripheral or coronary stent placed into narrowed, diseased peripheral or coronary arteries that slowly releases a drug to block cell proliferation. This prevents fibrosis that, together with clots , could otherwise block the stented artery, a process called restenosis...
s and thrombolytic drug
Thrombolytic drug
Thrombolytic drugs are used in medicine to dissolve blood clots in a procedure termed thrombolysis. They limit the damage caused by the blockage of the blood vessel.-Uses:...
therapy are less invasive options for less severe cases.
Epidemiology
Eighty percent of cases are in women, and a third late in pregnancy or shortly after.See also
- Dissection (medical)Dissection (medical)In medical pathology, dissection refers to a tear within the wall of a blood vessel, which allows blood to separate the wall layers, creating a pseudoaneurysm.- Types :Examples include:*Aortic dissection...
- Aortic dissectionAortic dissectionAortic dissection occurs when a tear in the inner wall of the aorta causes blood to flow between the layers of the wall of the aorta and force the layers apart. The dissection typically extends anterograde, but can extend retrograde from the site of the intimal tear. Aortic dissection is a medical...
, a similar condition affecting a different artery