Right-sided aortic arch is rare, with a prevalence among adults of about 0.01%.

Establishing the incidence of aortic dissection has been difficult because many cases are only diagnosed after death (which may have been attributed to another cause), and is often initially misdiagnosed. Aortic dissection affects an estimated 2.0–3.5 people per every 100,000 every year. Studies from Sweden suggest that the incidence of aortic dissection may be rising. Men are more commonly affected than women: 65% of all people with aortic dissection are male. The mean age at diagnosis is 63 years. In females before the age of 40, half of all aortic dissections occur during pregnancy (typically in the third trimester or early postpartum period).

Aortic dissection is associated with hypertension (high blood pressure) and many connective tissue disorders. Vasculitis (inflammation of an artery) is rarely associated with aortic dissection. It can also be the result of chest trauma. About 72 to 80% of individuals who present with an aortic dissection have a previous history of hypertension. Illicit drug use with stimulants such as cocaine and methamphetamine is also a modifiable risk factor for AD.

A bicuspid aortic valve (a type of congenital heart disease involving the aortic valve) is found in 7–14% of individuals who have an aortic dissection. These individuals are prone to dissection in the ascending aorta. The risk of dissection in individuals with bicuspid aortic valve is not associated with the degree of stenosis of the valve.

Connective tissue disorders such as Marfan syndrome, Ehlers-Danlos syndrome, and Loeys–Dietz syndrome increase the risk of aortic dissection. Similarly, vasculitides such as Takayasu's arteritis, giant cell arteritis, polyarteritis nodosa, and Behcet's disease have been associated with a subsequent aortic dissection. Marfan's syndrome is found in 5-9% of individuals who suffer from an aortic dissection. In this subset, the incidence in young individuals is increased. Individuals with Marfan syndrome tend to have aneurysms of the aorta and are more prone to proximal dissections of the aorta.

Turner syndrome also increases the risk of aortic dissection, by aortic root dilatation.

Chest trauma leading to aortic dissection can be divided into two groups based on cause: blunt chest trauma (commonly seen in car accidents) and iatrogenic. Iatrogenic causes include trauma during cardiac catheterization or due to an intra-aortic balloon pump.

Aortic dissection may be a late sequela of heart surgery. About 18% of individuals who present with an acute aortic dissection have a history of open-heart surgery. Individuals who have undergone aortic valve replacement for aortic insufficiency are at particularly high risk because aortic insufficiency causes increased blood flow in the ascending aorta. This can cause dilatation and weakening of the walls of the ascending aorta.

Syphilis only potentially causes aortic dissection in its tertiary stage.

Hypertension and cigarette smoking are the most important risk factors, though the importance of genetic factors has been increasingly recognized. Approximately 10% of patients may have other family members who have aortic aneurysms. It is also important to note that individuals with a history of aneurysms in other parts of the body have a higher chance of developing a thoracic aortic aneurysm.

Quadricuspid aortic valves are very rare cardiac valvular anomalies with a prevalence of 0.013% to 0.043% of cardiac cases and a prevalence of 1 in 6000 patients that undertake aortic valve surgery. There is a slight male predominance in all of the cases, and the mean age is 50.7.

The causes of right-sided aortic arch are still unknown. 22q11 deletions have been found in some patients.

Mortality from aortic rupture is up to 90%. 65–75% of patients die before they arrive at hospital and up to 90% die before they reach the operating room.

In Heyde's syndrome, aortic stenosis is associated with gastrointestinal bleeding due to angiodysplasia of the colon. Recent research has shown that the stenosis causes a form of von Willebrand disease by breaking down its associated coagulation factor (factor VIII-associated antigen, also called von Willebrand factor), due to increased turbulence around the stenotic valve.

Bicuspid aortic valves are the most common cardiac valvular anomaly, occurring in 1–2% of the general population. It is twice as common in males as in females.

Bicuspid aortic valve is a heritable condition, with a demonstrated association with mutations in the NOTCH1 gene. Its heritability (formula_1) is as high as 89%. Both familial clustering and isolated valve defects have been documented. The incidence of bicuspid aortic valve can be as high as 10% in families affected with the valve problem..Recent studies suggest that BAV is an autosomal dominant condition with incomplete penetrance. Other congenital heart defects are associated with bicuspid aortic valve at various frequencies, including coarctation of the aorta.

Little is known regarding the exact causes of aortic arch anomalies. However, the association with chromosome 22q11 deletion (CATCH 22) implies that a genetic component is likely in certain cases. Esophageal atresia also occurs in some patients with double aortic arch.

Each year in the United States, some 45,000 people die from diseases of the aorta and its branches. Acute aortic dissection, a life-threatening event due to a tear in the aortic wall, affects 5 to 10 patients per million population each year, most often men between the ages of 50 and 70; of those that occur in women younger than 40, nearly half arise during pregnancy. The majority of these deaths occur as a result of complications of thoracic aneurysmal disease.

If untreated, severe symptomatic aortic stenosis carries a poor prognosis with a 2-year mortality rate of 50-60% and a 3-year survival rate of less than 30%. Prognosis after aortic valve replacement for people who are younger than 65 is about five years less than that of the general population; for people older than 65 it is about the same.

An aortic aneurysm can occur as a result of trauma, infection, or, most commonly, from an intrinsic abnormality in the elastin and collagen components of the aortic wall. While definite genetic abnormalities were identified in true genetic syndromes (Marfan, Elher-Danlos and others) associated with aortic aneurysms, both thoracic and abdominal aortic aneurysms demonstrate a strong genetic component in their aetiology.

Complete vascular rings represent about 0.5-1% of all congenital cardiovascular malformations. The majority of these are double aortic arches.

There is no known gender preference, i.e. males and females are about equally affected. There is also no known ethnic or geographic disposition.

Associated cardiovascular anomalies are found in 10-15% of patients. These include:

- Atrial septal defect (ASD)

- Ventricular septal defect (VSD)

- Patent ductus arteriosus (PDA)

- Tetralogy of Fallot (ToF)

- Transposition of the great arteries (D-TGA)

Inheritance is thought to be rather complex. There is a good amount of evidence that shows the disease is autosomal dominant, with some penetrance. There is also the possibility of age related dependence. It is known that Marfan’s Syndrome and Ehler-Danlos Syndrome lead to an increased risk for development of FAD. Marfan’s Syndrome is not required to have an aortic dissection. One study suggests that the chromosomal locus for the gene is 5q13-14. The same study found that other genes may be linked, and include loci for Marfan and Ehler-Danlos Syndromes, genes for metalloproteinase 3 and 9, and tissue inhibitor of malloproteinase 2 as well as two loci on chromosomes 5q13-14 and lq23.2-24. Still other studies show that mutations in smooth muscle cell-specific isoforms of alpha actin and beta myosin heavy chain may cause FAD. Mutations in the genes TGFBR 1 and 2 are known to cause dissections in aortas with normal diameter size (>4.3 cm) and gene "FPN1" mutations typically affect aortas with larger diameters (<4.4 cm).

There are several hypotheses which attempt to explain how the dissection physically occurs. The first states that a tear develops in the intima layer of the aorta which allows blood to flow from the lumen of the aorta into the intima. This event creates a dissection and essentially two lumens. The second hypothesis suggests that the vasa vasorum ruptures and causes a hemorrhage in the wall of the aorta. The hemorrhaging promotes tearing of the intima and eventually aortic dissection.

The major risk factors for FAD include high blood pressure, old age, haematoma, genetic weakening of aortic wall, cocaine use, pregnancy and diseases causing abnormal connective tissue. One study found that the average age(s) for the occurrence of dissection caused by degenerative aneurysm is 65 years and up. Dissections thought to be the result of genetic mutations appear to be more likely to occur between the ages of 40 and 60. Another study found that 20% of patients with FAD have a close relative with a history of thoracic aortic aneurysm or dissection which suggests yet another major risk factor.

The risk of aneurysm enlargement may be diminished with attention to the patient's blood pressure, smoking and cholesterol levels. There have been proposals to introduce ultrasound scans as a screening tool for those most at risk: men over the age of 65. The tetracycline antibiotic doxycycline is currently being investigated for use as a potential drug in the prevention of aortic aneurysm due to its metalloproteinase inhibitor and collagen stabilizing properties. In contrast, fluoroquinolones antibiotics are being investigated as a potential contributor to aortic aneurysms, given their tendency to break down collagen fibrils.

Anacetrapib is a cholesteryl ester transfer protein inhibitor that raises high-density lipoprotein (HDL) cholesterol and reduces low-density lipoprotein (LDL) cholesterol.

Anacetrapib reduces progression of atherosclerosis, mainly by reducing non-HDL-cholesterol, improves lesion stability and adds to the beneficial effects of atorvastatin

Elevating the amount of HDL cholesterol in the abdominal area of the aortic artery in mice both reduced the size of aneurysms that had already grown and prevented abdominal aortic aneurysms from forming at all. In short, raising HDL cholesterol is beneficial because it induces programmed cell death. The walls of a failing aorta are replaced and strengthened. New lesions should not form at all when using this drug.

Treatment consists of open heart surgery soon after birth. Awaiting surgery, prostaglandin can be administered to keep the ductus arteriosus open, thereby allowing blood flow to the lower body. Failure to treat the condition yields a mortality rate of 90% at a median age of 4 days.

Familial aortic dissection or FAD refers to the splitting of the wall of the aorta in either the arch, ascending or descending portions. FAD is thought to be passed down as an autosomal dominant disease and once inherited will result in dissection of the aorta, and dissecting aneurysm of the aorta, or rarely aortic or arterial dilation at a young age. Dissection refers to the actual tearing open of the aorta. However, the exact gene(s) involved has not yet been identified. It can occur in the absence of clinical features of Marfan syndrome and of systemic hypertension. Over time this weakness, along with systolic pressure, results in a tear in the aortic intima layer thus allowing blood to enter between the layers of tissue and cause further tearing. Eventually complete rupture of the aorta occurs and the pleural cavity fills with blood. Warning signs include chest pain, ischemia, and hemorrhaging in the chest cavity. This condition, unless found and treated early, usually results in death. Immediate surgery is the best prognosis in most cases. FAD is not to be confused with PAU (penetrating atherosclerotic ulcers) and IMH (intramural hematoma), both of which present in ways similar to that of familial aortic dissection.

Hypertension is defined when a patient's blood pressure in the arm exceeds 140/90 mmHg under normal conditions. This is a severe problem for the heart and can cause many other complications. In a study of 120 coarctation repair recipients done in Groningen, The Netherlands, twenty-nine patients (25%) experienced hypertension in the later years of life due to the repair. While hypertension has many different factors that lead to this stage of blood pressure, people who have had a coarctation repair — regardless of the age at which the operation was performed — are at much higher risk than the general public of hypertension later in life. Undetected chronic hypertension can lead to sudden death among coarctation repair patients, at higher rates as time progresses.

Angioplasty is a procedure done to dilate an abnormally narrow section of a blood vessel to allow better blood flow. This is done in a cardiac catheterization laboratory. Typically taking two to three hours, the procedure may take longer but usually patients are able to leave the hospital the same day. After a coarctation repair 20-60% of infant patients may experience reoccurring stenosis at the site of the original operation. This can be fixed by either another coarctectomy.

Coronary artery disease (CAD) is a major issue for patients who have undergone a coarctation repair. Many years after the procedure is done, heart disease not only has an increased chance of affecting coarctation patients, but also progresses through the levels of severity at an alarmingly increased rate. In a study conducted by Mare Cohen, MD, et al., one fourth of the patients who experienced a coarctation died of heart disease, some at a relatively young age.

Clinical criteria are used in most studies when defining recurrence of coarctation (recoarctation) when blood pressure is at a difference of >20 mmHg between the lower and upper limbs. This procedure is most common in infant patients and is uncommon in adult patients. In a study conducted by Koller et al., 10.8% of infant patients underwent recoarctations at less than two years of age while another 3.1% of older children received a recoarctation.

People who have had a coarctation of the aorta are likely to have bicuspid aortic valve disease. Between 20% and 85% of patients are affected with this disease. Bicuspid aortic valve disease is a big contributor to cardiac failure, which in turn makes up roughly 20% of late deaths to coarctation patients.

The risk of death in individuals with aortic insufficiency, dilated ventricle, normal ejection fraction who are asymptomatic is about 0.2 percent per year. Risk increases if the ejection fraction decreases or if the individual develops symptoms.

Individuals with chronic (severe) aortic regurgitation follow a course that once symptoms appear, surgical intervention is needed. AI is fatal in 10 to 20% of individuals who do not undergo surgery for this condition. Left ventricle dysfunction determines to an extent the outlook for severity of aortic regurgitation cases.

Supravalvular aortic stenosis is associated with genetic damage at the Elastin gene locus on chromosome 7q11.23. Fluorescent in situ hybridisation techniques have revealed that 96% of patients with Williams syndrome, where supravalvular aortic stenosis is characteristic, have a hemizygous deletion of the Elastin gene. Further studies have shown that patients with less extensive deletions featuring the Elastin gene also tend to develop supravalvular aortic stenosis

Annuloaortic ectasia is a dilation of the proximal ascending aorta and aortic annulus. It may cause aortic regurgitation, thoracic aortic dissection, aneurysm and rupture. It is often associated with connective tissue diseases like Marfan syndrome and Ehlers Danlos Syndrome. It can also be a complication due to tertiary syphilis. In tertiary syphilis the aortic root becomes so dilated that the aortic valve becomes incompetent and cor bovinum results.

The term was first coined by the American heart surgeon Denton Cooley in 1961.

Bicuspid aortic valve abnormality is seen in 1 to 2 percent of all live births. It is associated with a number of mutations affecting Notch signalling pathway.

Unfortunately, coarctations can not be prevented because they are usually present at birth. The best thing for patients who are affected by coarctations is early detection. Some signs that can lead to a coarctation have been linked to pathologies such as Turner syndrome, bicuspid aortic valve, and other family heart conditions.

The most common cause of aortic rupture is a ruptured aortic aneurysm. Other causes include trauma and iatrogenic (procedure-related) causes.