Left ventricular thrombus is a blood clot (thrombus) in the left ventricle of the heart. LVT is a common complication of acute myocardial infarction (AMI). Typically the clot is a mural thrombus, meaning it is on the wall of the ventricle. The primary risk of LVT is the occurrence of cardiac embolism, in which the thrombus detaches from the ventricular wall and travels through the circulation and blocks blood vessels. Blockage can be especially damaging in the heart or brain (stroke).

LVT occurs most often during the first 2 weeks following AMI. AMI patients most at risk display the 3 characteristics of Virchow's triad:

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.

Signs and symptoms of ischemic cardiomyopathy include sudden fatigue, shortness of breath, dizziness and palpitations.

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.

Ventricular aneurysms are usually complications resulting from a heart attack. When the heart muscle (cardiac muscle) partially dies during a heart attack, a layer of muscle may survive, and, being severely weakened, start to become an aneurysm. Blood may flow into the surrounding dead muscle and inflate the weakened flap of muscle into a bubble. It may also be congenital.

Ventricular aneurysms are one of the many complications that may occur after a heart attack. The word aneurysm refers to a bulge or ‘pocketing’ of the wall or lining of a vessel commonly occurring in the blood vessels at the base of the septum, or within the aorta. In the heart, they usually arise from a patch of weakened tissue in a ventricular wall, which swells into a bubble filled with blood. This, in turn, may block the passageways leading out of the heart, leading to severely constricted blood flow to the body. Ventricular aneurysms can be fatal. They are usually non-rupturing because they are lined by scar tissue.

A left ventricular aneurysm can be associated with ST elevation.

A myocardial infarction may compromise the function of the heart as a pump for the circulation, a state called heart failure. There are different types of heart failure; left- or right-sided (or bilateral) heart failure may occur depending on the affected part of the heart, and it is a low-output type of failure. If one of the heart valves is affected, this may cause dysfunction, such as mitral regurgitation in the case of left-sided coronary occlusion that disrupts the blood supply of the papillary muscles. The incidence of heart failure is particularly high in patients with diabetes and requires special management strategies.

Ischemic cardiomyopathy is a type of cardiomyopathy caused by a narrowing of the coronary arteries which supply blood to the heart. Typically, patients with ischemic cardiomyopathy have a history of acute myocardial infarction, however, it may occur in patients with coronary artery disease, but without a past history of acute myocardial infarction. This cardiomyopathy is one of the leading causes of sudden cardiac death.

PVF is defined as ventricular fibrillation not preceded by heart failure or shock, in contrast to secondary ventricular fibrillation, which is.

Approximately 10% of all myocardial infarctions lead to PVF. The incidence peaks between 20 and 50 minutes after the start of the MI. 2/3 of events occur before medical attendance, and of these medically unattended events, 2/3 occur after more than 30 minutes of warning symptoms.

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.

Myocardial infarction complications may occur immediately following a heart attack (in the acute phase), or may need time to develop (a chronic problem). After an infarction, an obvious complication is a second infarction, which may occur in the domain of another atherosclerotic coronary artery, or in the same zone if there are any live cells left in the infarct.

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.

Arterial thrombosis is the formation of a thrombus within an artery. In most cases, arterial thrombosis follows rupture of atheroma (a fat-rich deposit in the blood vessel wall), and is therefore referred to as "atherothrombosis". Arterial embolism occurs when clots then migrate downstream, and can affect any organ.

Alternatively, arterial occlusion occurs as a consequence of embolism of blood clots originating from the heart ("cardiogenic" emboli). The most common cause is atrial fibrillation, which causes a blood stasis within the atria with easy thrombus formation, but blood clots can develop inside the heart for other reasons too.

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.

Dressler syndrome was, historically, a phenomenon complicating about 7% of myocardial infarctions; however, in the era of percutaneous coronary intervention, it is very uncommon. The disease consists of a persistent low-grade fever, chest pain (usually pleuritic in nature), pericarditis (usually evidenced by a pericardial friction rub), and/or a pericardial effusion. The symptoms tend to occur 2–3 weeks after myocardial infarction, but can also be delayed for a few months. It tends to subside in a few days, and very rarely leads to pericardial tamponade. An elevated ESR is an objective, yet nonspecific, laboratory finding.

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.

Dressler syndrome needs to be differentiated from pulmonary embolism, another identifiable cause of pleuritic (and non-pleuritic) chest pain in people who have been hospitalized and/or undergone surgical procedures within the preceding weeks.

Symptoms of cerebral infarction are determined by the parts of the brain affected. If the infarct is located in primary motor cortex, contralateral hemiparesis is said to occur. With brainstem localization, brainstem syndromes are typical: Wallenberg's syndrome, Weber's syndrome, Millard-Gubler syndrome, Benedikt syndrome or others.

Infarctions will result in weakness and loss of sensation on the opposite side of the body. Physical examination of the head area will reveal abnormal pupil dilation, light reaction and lack of eye movement on opposite side. If the infarction occurs on the left side brain, speech will be slurred. Reflexes may be aggravated as well.

The typical presentation of takotsubo cardiomyopathy is a sudden onset of chest pain associated with ECG changes mimicking a myocardial infarction of the anterior wall. During the course of evaluation of the patient, a bulging out of the left ventricular apex with a hypercontractile base of the left ventricle is often noted. It is the hallmark bulging out of the apex of the heart with preserved function of the base that earned the syndrome its name "tako tsubo", or octopus pot in Japan, where it was first described.

Stress is the main factor in takotsubo cardiomyopathy, with more than 85% of cases set in motion by either a physically or emotionally stressful event that prefaces the start of symptoms. Examples of emotional stressors include grief from the death of a loved one, fear of public speaking, arguing with a spouse, relationship disagreements, betrayal, and financial problems. Acute asthma, surgery, chemotherapy, and stroke are examples of physical stressors. In a few cases, the stress may be a happy event, such as a wedding, winning a jackpot, a sporting triumph, or a birthday.

Takotsubo cardiomyopathy is more commonly seen in postmenopausal women. Often there is a history of a recent severe (usually negative, sometimes happy) emotional or physical stress.

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.

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.

There are various classification systems for a cerebral infarction.

- The Oxford Community Stroke Project classification (OCSP, also known as the Bamford or Oxford classification) relies primarily on the initial symptoms. Based on the extent of the symptoms, the stroke episode is classified as total anterior circulation infarct (TACI), partial anterior circulation infarct (PACI), lacunar infarct (LACI) or posterior circulation infarct (POCI). These four entities predict the extent of the stroke, the area of the brain affected, the underlying cause, and the prognosis.

- The TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification is based on clinical symptoms as well as results of further investigations; on this basis, a stroke is classified as being due to (1) thrombosis or embolism due to atherosclerosis of a large artery, (2) embolism of cardiac origin, (3) occlusion of a small blood vessel, (4) other determined cause, (5) undetermined cause (two possible causes, no cause identified, or incomplete investigation).

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).