Pulmonary artery sling is a rare condition in which the left pulmonary artery anomalously originates from a normally positioned right pulmonary artery. The left pulmonary artery arises anterior to the right main bronchus near its origin from the trachea, courses between the trachea and the esophagus and enters the left hilum. Symptoms include cyanosis, dyspnoea and apnoeic spells. It almost always requires surgical intervention. Rarely it is asymptomatic and is detected incidentally in asymptomatic adults.

The anomalous venous return forms a curved shadow on chest x-ray such that it resembles a scimitar. This is called the Scimitar Sign. Associated abnormalities include right lung hypoplasia with associated dextroposition of the heart, pulmonary artery hypoplasia and pulmonary sequestration.Incidence is around 1 per 100,000 births.

The symptoms of pulmonary hypertension include the following:

Less common signs/symptoms include non-productive cough and exercise-induced nausea and vomiting. Coughing up of blood may occur in some patients, particularly those with specific subtypes of pulmonary hypertension such as heritable pulmonary arterial hypertension, Eisenmenger syndrome and chronic thromboembolic pulmonary hypertension. Pulmonary venous hypertension typically presents with shortness of breath while lying flat or sleeping (orthopnea or paroxysmal nocturnal dyspnea), while pulmonary arterial hypertension (PAH) typically does not.

Other typical signs of pulmonary hypertension include an accentuated pulmonary component of the second heart sound, a right ventricular third heart sound, and parasternal heave indicating a hypertrophied right atrium. Signs of systemic congestion resulting from right-sided heart failure include jugular venous distension, ascites, and hepatojugular reflux. Evidence of tricuspid insufficiency and pulmonic regurgitation is also sought and, if present, is consistent with the presence of pulmonary hypertension.

Scimitar syndrome, or congenital pulmonary venolobar syndrome, is a rare congenital heart defect characterized by anomalous venous return from the right lung (to the systemic venous drainage, rather than directly to the left atrium). This anomalous pulmonary venous return can be either partial (PAPVR) or total (TAPVR). The syndrome associated with PAPVR is more commonly known as "Scimitar syndrome" after the curvilinear pattern created on a chest radiograph by the pulmonary veins that drain to the inferior vena cava. This radiographic density often has the shape of a scimitar, a type of curved sword. The syndrome was first described by Catherine Neill in 1960.

Clinical symptoms and signs are often non-specific or absent in early CTEPH, with signs of right heart failure only in advanced disease. The main symptom of CTEPH is exertional breathlessness (shortness of breath during exertion such as exercise), which is unspecific and may often be attributed to other, more common, diseases by physicians. When present, the clinical symptoms of CTEPH may resemble those of acute PE, or of idiopathic pulmonary arterial hypertension (iPAH). Leg oedema (swelling) and haemoptysis (blood in mucus) occur more often in CTEPH, while syncope (fainting) is more common in iPAH.

Stenosis of the pulmonary artery is a condition where the pulmonary artery is subject to an abnormal constriction (or stenosis). Peripheral pulmonary artery stenosis may occur as an isolated event or in association with Alagille syndrome, Berardinelli-Seip congenital lipodystrophy type 1, Costello syndrome, Keutel syndrome, nasodigitoacoustic syndrome (Keipert syndrome), Noonan syndrome or Williams syndrome.

It should not be confused with a pulmonary valve stenosis, which is in the heart, but can have similar hemodynamic effects. Both stenosis of the pulmonary artery and pulmonary valve stenosis are causes of pulmonic stenosis.

In some cases it is treated with surgery.

d vessels can present a large variety of , and/or . The effects may range from a change in blood pressure to an interruption in circulation, depending on the nature and degree of the misplacement and which vessels are involved.

Although "transposed" literally means "swapped", many types of TGV involve vessels that are in abnormal positions, while not actually being swapped with each other. The terms TGV and TGA are most commonly used in reference to dextro-TGA – in which the arteries "are" in swapped positions; however, both terms are also commonly used, though to a slightly lesser extent, in reference to levo-TGA – in which both the arteries and the ventricles are swapped; while other defects in this category are almost never referred to by either of these terms.

According to WHO classification there are 5 groups of PH, where Group I (pulmonary arterial hypertension) is further subdivided into Group I' and Group I" classes. The most recent WHO classification system (with adaptations from the more recent ESC/ERS guidelines shown in italics) can be summarized as follows:

WHO Group I – Pulmonary arterial hypertension (PAH)

- Idiopathic

- Heritable (BMPR2, ALK1, SMAD9, caveolin 1, KCNK3 mutations)

- Drug- and toxin-induced (e.g., methamphetamine use)

- Associated conditions:Connective tissue disease, HIV infection, Portal hypertension, Congenital heart diseases, Schistosomiasis

WHO Group I' – Pulmonary veno-occlusive disease (PVOD), pulmonary capillary hemangiomatosis (PCH)

- Idiopathic

- Heritable (EIF2AK4 mutations)

- Drugs, toxins and radiation-induced

- Associated conditions:connective tissue disease, HIV infection

WHO Group I" – Persistent pulmonary hypertension of the newborn

WHO Group II – Pulmonary hypertension secondary to left heart disease

- Left ventricular Systolic dysfunction

- Left ventricular Diastolic dysfunction

- Valvular heart disease

- Congenital/acquired left heart inflow/outflow tract obstruction and congenital cardiomyopathy

- Congenital/acquired pulmonary venous stenosis

WHO Group III – Pulmonary hypertension due to lung disease, chronic hypoxia

- Chronic obstructive pulmonary disease (COPD)

- Interstitial lung disease

- Mixed restrictive and obstructive pattern pulmonary diseases

- Sleep-disordered breathing

- Alveolar hypoventilation disorders

- Chronic exposure to high altitude

- Developmental abnormalities

WHO Group IV – chronic arterial obstruction

- Chronic thromboembolic pulmonary hypertension (CTEPH)

- Other pulmonary artery obstructions

- Angiosarcoma or other tumor within the blood vessels

- Arteritis

- Congenital pulmonary artery stenosis

- Parasitic infection (hydatidosis)

WHO Group V – Pulmonary hypertension with unclear or multifactorial mechanisms

- Hematologic diseases: chronic hemolytic anemia (including sickle cell disease)

- Systemic diseases: sarcoidosis, pulmonary Langerhans cell histiocytosis: lymphangioleiomyomatosis, neurofibromatosis, vasculitis

- Metabolic disorders: glycogen storage disease, Gaucher disease, thyroid diseases

- Others: pulmonary tumoral thrombotic microangiopathy, fibrosing mediastinitis, chronic kidney failure, segmental pulmonary hypertension (pulmonary hypertension restricted to one or more lobes of the lungs)

In dextro-Transposition of the great arteries (dextro-TGA) deoxygenated blood from the right heart is pumped immediately through the aorta and circulated to the body and the heart itself, bypassing the lungs altogether, while the left heart pumps oxygenated blood continuously back into the lungs through the pulmonary artery. In effect, two separate "circular" (parallel) circulatory systems are created. It is called a cyanotic congenital heart defect (CHD) because the newborn infant turns blue from lack of oxygen.

The treatment of choice is percutaneous balloon valvuloplasty and is done when a resting peak gradient is seen to be >60mm Hg or a mean >40mm Hg is observed.

Chronic thromboembolic pulmonary hypertension (CTEPH) is a long-term disease caused by a blockage in the blood vessels that deliver blood from the heart to the lungs (pulmonary arteries), resulting in increased pressure in these arteries (pulmonary hypertension). The blockage either results from a hardened blood clot that is thought to originate from the deep veins of the body (thromboembolism) and remains in the arteries, or from a scar that forms at the site where the clot has damaged the arteries, causing permanent fibrous obstruction (blood flow blockage). Most patients have a combination of microvascular (small vessel) and macrovascular (large vessel) obstruction. Some patients may present with normal or near-normal pulmonary pressures at rest despite symptomatic disease. These patients are labelled as having chronic thromboembolic disease (CTED).

Diagnosis is based on findings obtained after at least 3 months of effective anticoagulation therapy (blood thinners) in order to discriminate this condition from ‘subacute’ pulmonary embolism (blood clot in the lungs, PE). Diagnostic findings for CTEPH are:

1. Invasively (i.e., in the blood) measured mean pulmonary arterial pressure (mPAP) ≥25 mmHg;

2. Mismatched perfusion defects on lung ventilation/perfusion (V/Q) scan and specific diagnostic signs for CTEPH seen by multidetector computed tomography angiography (MDCT), magnetic resonance imaging (MRI) or conventional pulmonary cineangiography (PAG), such as ring-like stenoses, webs/slits, chronic total occlusions (pouch lesions, or tapered lesions) and tortuous lesions.

Pulmonic stenosis, also known as pulmonary stenosis, is a dynamic or fixed obstruction of flow from the right ventricle of the heart to the pulmonary artery. It is usually first diagnosed in childhood.

Pulmonic stenosis is usually due to isolated valvular obstruction (pulmonary valve stenosis), but it may be due to subvalvular or supravalvular obstruction, such as infundibular stenosis. It may occur in association with other congenital heart defects as part of more complicated syndromes (for example, tetralogy of Fallot).

Among some of the symptoms consistent with pulmonary valve stenosis are the following:

- Heart murmur

- Cyanosis

- Dyspnea

- Dizziness

- Upper thorax pain

- Developmental disorders

Because pulmonic regurgitation is the result of other factors in the body, any noticeable symptoms are ultimately caused by an underlying medical condition rather than the regurgitation itself. However, more severe regurgitation may contribute to right ventricular enlargement by dilation, and in later stages, right heart failure. A diastolic decrescendo murmur can sometimes be identified,( heard best) over the left lower sternal border.

The resulting syndrome depends on the structure affected.

Examples of vascular stenotic lesions include:

- Intermittent claudication (peripheral artery stenosis)

- Angina (coronary artery stenosis)

- Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes)

- Renal artery stenosis

The types of stenoses in heart valves are:

- Pulmonary valve stenosis, which is the thickening of the pulmonary valve, therefore causing narrowing

- Mitral valve stenosis, which is the thickening of the mitral valve (of the left heart), therefore causing narrowing

- Tricuspid valve stenosis, which is the thickening of the tricuspid valve (of the right heart), therefore causing narrowing

- Aortic valve stenosis, which is the thickening of the aortic valve, therefore causing narrowing

Stenoses/strictures of other bodily structures/organs include:

- Pyloric stenosis (gastric outflow obstruction)

- Lumbar, cervical or thoracic spinal stenosis

- Subglottic stenosis (SGS)

- Tracheal stenosis

- Obstructive jaundice (biliary tract stenosis)

- Bowel obstruction

- Phimosis

- Non-communicating hydrocephalus

- Stenosing tenosynovitis

- Atherosclerosis

- Esophageal stricture

- Achalasia

- Prinzmetal angina

- Vaginal stenosis

Stenoses of the vascular type are often associated with unusual blood sounds resulting from turbulent flow over the narrowed blood vessel. This sound can be made audible by a stethoscope, but diagnosis is generally made or confirmed with some form of medical imaging.

Persistent truncus arteriosus (or Patent truncus arteriosus or Common arterial trunk), is a rare form of congenital heart disease that presents at birth. In this condition, the embryological structure known as the truncus arteriosus fails to properly divide into the pulmonary trunk and aorta. This results in one arterial trunk arising from the heart and providing mixed blood to the coronary arteries, pulmonary arteries, and systemic circulation.

The most well-known classification was the fourfold system developed by Collett and Edwards in 1949. Collett/Edwards Types I, II, and III are distinguished by the branching pattern of the pulmonary arteries:

- Type I: truncus -> one pulmonary artery -> two lateral pulmonary arteries

- Type II: truncus -> two posterior/posterolateral pulmonary arteries

- Type III: truncus -> two lateral pulmonary arteries

The "Type IV" proposed in 1949 is no longer considered a form of PTA by most modern sources.

Another well-known classification was defined by Van Praaghs in 1965.

Pulmonary insufficiency (or incompetence, or regurgitation) is a condition in which the pulmonary valve is incompetent and allows backflow from the pulmonary artery to the right ventricle of the heart during diastole. While a small amount of backflow may occur ordinarily, it is usually only shown on an echocardiogram and is harmless. More pronounced regurgitation that is noticed through a routine physical examination is a medical sign of disease and warrants further investigation. If it is secondary to pulmonary hypertension it is referred to as a Graham Steell murmur.

Common symptoms include:

- tachycardia (a heart rate exceeding the normal resting rate)

- respiratory problems

- dyspnea (shortness of breath)

- continuous "machine-like" (also described as "rolling-thunder" and "to-and-fro") heart murmur (usually from aorta to pulmonary artery, with higher flow during systole and lower flow during diastole)

- cardiomegaly (enlarged heart, reflecting ventricular dilation and volume overload)

- left subclavicular thrill

- bounding pulse

- widened pulse pressure

- increased cardiac output

- increased systolic pressure

- poor growth

- differential cyanosis, i.e. cyanosis of the lower extremities but not of the upper body.

Patients typically present in good health, with normal respirations and heart rate. If the PDA is moderate or large, widened pulse pressure and bounding peripheral pulses are frequently present, reflecting increased left ventricular stroke volume and diastolic run-off of blood into the (initially lower-resistance) pulmonary vascular bed. Prominent suprasternal and carotid pulsations may be noted secondary to increased left ventricular stroke volume.

Pulmonary atresia is a congenital malformation of the pulmonary valve in which the valve orifice fails to develop. The valve is completely closed thereby obstructing the outflow of blood from the heart to the lungs. The pulmonary valve is located on the right side of the heart between the right ventricle and pulmonary artery. In a normal functioning heart, the opening to the pulmonary valve has three flaps that open and close

In congenital heart defects such as pulmonary atresia, one finds that these structural abnormalities can include the valves of the heart, as well as, the walls and arteries/veins near the heart muscle. Consequently, blood flow due to the aforementioned structural abnormalities, is affected, either by blocking or altering the flow of blood through the human cardiac muscle.

In regards to the cause of pulmonary valve stenosis a very high percentage are congenital, the right ventricular flow is hindered (or obstructed by this). The cause in turn is divided into: valvular, external and intrinsic (when it is acquired).

Symptoms may begin quickly or slowly depending on the size of the embolus and how much it blocks the blood flow. Symptoms of embolisation in an organ vary with the organ involved but commonly include:

- Pain in the involved body part

- Temporarily decreased organ function

Later symptoms are closely related to infarction of the affected tissue. This may cause permanently decreased organ function.

For example, symptoms of myocardial infarction mainly include chest pain, dyspnea, diaphoresis (an excessive form of sweating), weakness, light-headedness, nausea, vomiting, and palpitations.

Symptoms of limb infarction include coldness, decreased or no pulse beyond the site of blockage, pain, muscle spasm, numbness and tingling, pallor and muscle weakness, possibly to the grade of paralysis in the affected limb.

The symptoms/signs of pulmonary atresia that will occur in babies are consistent with cyanosis, some fatigue and some shortness of breath (eating may be a problem as well).

In the case of pulmonary atresia with ventricular septal defect, one finds that decreased pulmonary blood flow may cause associated defects such as:

- Tricuspid atresia

- Tetralogy of Fallot (severe)

- RV w/ double-outlet

The symptoms/signs of pulmonary heart disease (cor pulmonale) can be non-specific and depend on the stage of the disorder, and can include blood backing up into the systemic venous system, including the hepatic vein. As pulmonary heart disease progresses, most individuals will develop symptoms like: