"Total anomalous pulmonary venous connection", also known as "total anomalous pulmonary venous drainage" and "total anomalous pulmonary venous return", is a rare cyanotic congenital heart defect in which all four pulmonary veins are malpositioned and make anomalous connections to the systemic venous circulation. (Normally, pulmonary veins return oxygenated blood from the lungs to the left atrium where it can then be pumped to the rest of the body). A patent foramen ovale, patent ductui arteriosa or an atrial septal defect "must" be present, or else the condition is fatal due to a lack of systemic blood flow.

In some cases, it can be detected prenatally.

There are four variants: Supracardiac (50%): blood drains to one of the innominate veins (brachiocephalic veins) or the superior vena cava; Cardiac (20%), where blood drains into coronary sinus or directly into right atrium; Infradiaphragmatic (20%), where blood drains into portal or hepatic veins; and a mixed (10%) variant.

TAPVC can occur with "obstruction", which occurs when the anomalous vein enters a vessel at an acute angle and can cause pulmonary venous hypertension and cyanosis because blood cannot enter the new vein as easily.

Anomalous pulmonary venous connection (or anomalous pulmonary venous drainage or anomalous pulmonary venous return) is a congenital defect of the pulmonary veins.

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.

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.

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.

Symptoms of pulmonary embolism are typically sudden in onset and may include one or many of the following: dyspnea (shortness of breath), tachypnea (rapid breathing), chest pain of a "pleuritic" nature (worsened by breathing), cough and hemoptysis (coughing up blood). More severe cases can include signs such as cyanosis (blue discoloration, usually of the lips and fingers), collapse, and circulatory instability because of decreased blood flow through the lungs and into the left side of the heart. About 15% of all cases of sudden death are attributable to PE.

On physical examination, the lungs are usually normal. Occasionally, a pleural friction rub may be audible over the affected area of the lung (mostly in PE with infarct). A pleural effusion is sometimes present that is exudative, detectable by decreased percussion note, audible breath sounds, and vocal resonance. Strain on the right ventricle may be detected as a left parasternal heave, a loud pulmonary component of the second heart sound, and/or raised jugular venous pressure. A low-grade fever may be present, particularly if there is associated pulmonary hemorrhage or infarction.

As smaller pulmonary emboli tend to lodge in more peripheral areas without collateral circulation they are more likely to cause lung infarction and small effusions (both of which are painful), but not hypoxia, dyspnea or hemodynamic instability such as tachycardia. Larger PEs, which tend to lodge centrally, typically cause dyspnea, hypoxia, low blood pressure, fast heart rate and fainting, but are often painless because there is no lung infarction due to collateral circulation. The classic presentation for PE with pleuritic pain, dyspnea and tachycardia is likely caused by a large fragmented embolism causing both large and small PEs. Thus, small PEs are often missed because they cause pleuritic pain alone without any other findings and large PEs often missed because they are painless and mimic other conditions often causing ECG changes and small rises in troponin and BNP levels.

PEs are sometimes described as massive, submassive and nonmassive depending on the clinical signs and symptoms. Although the exact definitions of these are unclear, an accepted definition of massive PE is one in which there is hemodynamic instability such as sustained low blood pressure, slowed heart rate, or pulselessness.

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)

A paradoxical embolism, also called a crossed embolism, refers to an embolus which is carried from the venous side of circulation to the arterial side, or vice versa. It is a kind of stroke or other form of arterial thrombosis caused by embolism of a thrombus (blood clot), air, tumor, fat, or amniotic fluid of venous origin, which travels to the arterial side through a lateral opening in the heart, such as a patent foramen ovale, or arteriovenous shunts in the lungs.

The opening is typically an atrial septal defect, but can also be a ventricular septal defect.

Paradoxical embolisms represent two percent of arterial emboli.

Passage of a clot (thrombus) from a systemic vein to a systemic artery. When clots in systemic veins break off (embolize), they travel first to the right side of the heart and, normally, then to the lungs where they lodge, causing pulmonary embolism. On the other hand, when there is a hole at the septum, either upper chambers of the heart (an atrial septal defect) or lower chambers of the heart (ventricular septal defects), a clot can cross from the right to the left side of the heart, then pass into the systemic arteries as a paradoxical embolism. Once in the arterial circulation, a clot can travel to the brain, block a vessel there, and cause a stroke (cerebrovascular accident).

Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has traveled from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include shortness of breath, chest pain particularly upon breathing in, and coughing up blood. Symptoms of a blood clot in the leg may also be present such as a red, warm, swollen, and painful leg. Signs of a PE include low blood oxygen levels, rapid breathing, rapid heart rate, and sometimes a mild fever. Severe cases can lead to passing out, abnormally low blood pressure, and sudden death.

PE usually results from a blood clot in the leg that travels to the lung. The risk of blood clots is increased by cancer, prolonged bed rest, smoking, stroke, certain genetic conditions, estrogen-based medication, pregnancy, obesity, and after some types of surgery. A small proportion of cases are due to the embolization of air, fat, or amniotic fluid. Diagnosis is based on signs and symptoms in combination with test results. If the risk is low a blood test known as a D-dimer will rule out the condition. Otherwise a CT pulmonary angiography, lung ventilation/perfusion scan, or ultrasound of the legs may confirm the diagnosis. Together deep vein thrombosis and PE are known as venous thromboembolism (VTE).

Efforts to prevent PE include beginning to move as soon as possible after surgery, lower leg exercises during periods of sitting, and the use of blood thinners after some types of surgery. Treatment is typically with blood thinners such as heparin or warfarin. Often these are recommended for six months or longer. Severe cases may require thrombolysis using medication such as tissue plasminogen activator (tPA), or may require surgery such as a pulmonary thrombectomy. If blood thinners are not appropriate, a vena cava filter may be used.

Pulmonary emboli affect about 430,000 people each year in Europe. In the United States between 300,000 and 600,000 cases occur each year, which results in between 50,000 and 200,000 deaths. Rates are similar in males and females. They become more common as people get older.

Arterial embolism can cause occlusion in any part of the body. It is a major cause of infarction, tissue death due to the blockage of blood supply.

An embolus lodging in the brain from either the heart or a carotid artery will most likely be the cause of a stroke due to ischemia.

An arterial embolus might originate in the heart (from a thrombus in the left atrium, following atrial fibrillation or be a septic embolus resulting from endocarditis). Emboli of cardiac origin are frequently encountered in clinical practice. Thrombus formation within the atrium occurs mainly in patients with mitral valve disease, and especially in those with mitral valve stenosis (narrowing), with atrial fibrillation (AF). In the absence of AF, pure mitral regurgitation has a low incidence of thromboembolism.

The risk of emboli forming in AF depends on other risk factors such as age, hypertension, diabetes, recent heart failure, or previous stroke.

Thrombus formation can also take place within the ventricles, and it occurs in approximately 30% of anterior-wall myocardial infarctions, compared with only 5% of inferior ones. Some other risk factors are poor ejection fraction (<35%), size of infarct, and the presence of AF. In the first three months after infarction, left-ventricle aneurysms have a 10% risk of emboli forming.

Patients with prosthetic valves also carry a significant increase in risk of thromboembolism. Risk varies, based on the valve type (bioprosthetic or mechanical); the position (mitral or aortic); and the presence of other factors such as AF, left-ventricular dysfunction, and previous emboli.

Emboli often have more serious consequences when they occur in the so-called "end circulation": areas of the body that have no redundant blood supply, such as the brain and heart.

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.

When pulmonic stenosis (PS) is present, resistance to blood flow causes right ventricular hypertrophy. If right ventricular failure develops, right atrial pressure will increase, and this may result in a persistent opening of the foramen ovale, shunting of unoxygenated blood from the right atrium into the left atrium, and systemic cyanosis. If pulmonary stenosis is severe, congestive heart failure occurs, and systemic venous engorgement will be noted. An associated defect such as a patent ductus arteriosus partially compensates for the obstruction by shunting blood from the left ventricle to the aorta then back to the pulmonary artery (as a result of the higher pressure in the left ventricle) and back into the lungs.

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:

Embolism can be classified as to where it enters the circulation either in arteries or in veins. Arterial embolism are those that follow and, if not dissolved on the way, lodge in a more distal part of the systemic circulation. Sometimes, multiple classifications apply; for instance a pulmonary embolism is classified as an arterial embolism as well, in the sense that the clot follows the pulmonary artery carrying deoxygenated blood away from the heart. However, pulmonary embolism is generally classified as a form of venous embolism, because the embolus forms in veins, e.g. deep vein thrombosis.

A sinus venosus atrial septal defect is a type of atrial septal defect primarily associated with the sinus venosus.

They represent 5% of atrial septal defects.

They can occur near the superior vena cava or inferior vena cava, but the former are more common.

They can be associated with anomalous pulmonary venous connection.

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.

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

Superficial venous thromboses cause discomfort but generally not serious consequences, as do the deep venous thromboses (DVTs) that form in the deep veins of the legs or in the pelvic veins. Nevertheless, they can progress to the deep veins through the perforator veins or, they can be responsible for a lung embolism mainly if the head of the clot is poorly attached to the vein wall and is situated near the sapheno-femoral junction.

When a blood clot breaks loose and travels in the blood, this is called a venous thromboembolism (VTE). The abbreviation DVT/PE refers to a VTE where a deep vein thrombosis (DVT) has moved to the lungs (PE or pulmonary embolism).

Since the veins return blood to the heart, if a piece of a blood clot formed in a vein breaks off it can be transported to the right side of the heart, and from there into the lungs. A piece of thrombus that is transported in this way is an "embolus": the process of forming a thrombus that becomes embolic is called a "thromboembolism". An embolism that lodges in the lungs is a "pulmonary embolism" (PE). A pulmonary embolism is a very serious condition that can be fatal depending on the dimensions of the embolus. Venous thromboembolism (VTE) refers to both DVTs and PEs.

Systemic embolisms of venous origin can occur in patients with an atrial or ventricular septal defect, through which an embolus may pass into the arterial system. Such an event is termed a paradoxical embolism.

Cavernous sinus thrombosis is a specialised form of cerebral venous sinus thrombosis, where there is thrombosis of the cavernous sinus of the basal skull dura, due to the retrograde spread of infection and endothelial damage from the danger triangle of the face. The facial veins in this area anastomose with the superior and inferior ophthalmic veins of the orbit, which drain directly posteriorly into the cavernous sinus through the superior orbital fissure. Staphyloccoal or Streptococcal infections of the face, for example nasal or upper lip pustules may thus spread directly into the cavernous sinus, causing stroke-like symptoms of double vision, squint, as well as spread of infection to cause meningitis.

Pulmonary heart disease, also known as cor pulmonale is the enlargement and failure of the right ventricle of the heart as a response to increased vascular resistance (such as from pulmonic stenosis) or high blood pressure in the lungs.

Chronic pulmonary heart disease usually results in right ventricular hypertrophy (RVH), whereas acute pulmonary heart disease usually results in dilatation. Hypertrophy is an adaptive response to a long-term increase in pressure. Individual muscle cells grow larger (in thickness) and change to drive the increased contractile force required to move the blood against greater resistance. Dilatation is a stretching (in length) of the ventricle in response to acute increased pressure.

To be classified as pulmonary heart disease, the cause must originate in the pulmonary circulation system. Two causes are vascular changes as a result of tissue damage (e.g. disease, hypoxic injury), and chronic hypoxic pulmonary vasoconstriction. If left untreated, then death may result, RVH due to a defect is not classified as pulmonary heart disease. The heart and lungs are intricately related; whenever the heart is affected by a disease, the lungs risk following and vice versa.

Jugular vein thrombosis is a condition that may occur due to infection, intravenous drug use or malignancy. Jugular vein thrombosis can have a varying list of complications, including: systemic sepsis, pulmonary embolism, and papilledema. Though characterized by a sharp pain at the site of the vein, it can prove difficult to diagnose, because it can occur at random.

Symptoms of arterial gas embolism include:

- Loss of consciousness

- Cessation of breathing

- Vertigo

- Convulsions

- Tremors

- Loss of coordination

- Loss of control of bodily functions

- Numbness

- Paralysis

- Extreme fatigue

- Weakness in the extremities

- Areas of abnormal sensation

- Visual abnormalities

- Hearing abnormalities

- Personality changes

- Cognitive impairment

- Nausea or vomiting

- Bloody sputum

- Symptoms of other consequences of lung overexpansion such as pneumothorax, subcutaneous or mediastinal emphysema may also be present.

Common signs and symptoms of DVT include pain or tenderness, swelling, warmth, redness or discoloration, and distention of surface veins, although about half of those with the condition have no symptoms. Signs and symptoms alone are not sufficiently sensitive or specific to make a diagnosis, but when considered in conjunction with known risk factors, can help determine the likelihood of DVT. In most suspected cases, DVT is ruled out after evaluation, and symptoms are more often due to other causes, such as cellulitis, Baker's cyst, musculoskeletal injury, or lymphedema. Other differential diagnoses include hematoma, tumors, venous or arterial aneurysms, and connective tissue disorders.

Phlegmasia cerulea dolens is a very large and dangerous type of DVT. It is characterized by an acute and almost total venous occlusion of the entire extremity outflow, including the iliac and femoral veins. The leg is usually painful, tinged blue in color, and swollen, which may result in venous gangrene.

A venous thrombus is a blood clot (thrombus) that forms within a vein. "Thrombosis" is a term for a blood clot occurring inside a blood vessel. A common type of venous thrombosis is a deep vein thrombosis (DVT), which is a blood clot in the deep veins of the leg. If the thrombus breaks off (embolizes) and flows towards the lungs, it can become a pulmonary embolism (PE), a blood clot in the lungs.

An inflammatory reaction is usually present, mainly in the superficial veins and, for this reason this pathology is called most of the time thrombophlebitis. The inflammatory reaction and the white blood cells play a role in the resolution of venous clots.

The initial treatment for venous thromboembolism is typically with either low molecular weight heparin (LMWH) or unfractionated heparin. LMWH appears to have lower rates of side effects; however, both result in similar rates of survival.