Intracardiac thrombus

Definition

Intracardiac thrombosis is the presence of a thrombus in one of the heart chambers. Left heart thrombosis develops in atrial fibrillation, congenital and acquired cardiac malformations, and myocardial infarction. Lesion of the right heart chambers occurs as a component of pulmonary embolism (PE). With the intracardiac location of the thrombus, specific symptomatology is absent; clinical manifestations occur only when other cardiac pathologies complicate thrombosis. Classical and transesophageal echocardiography, cardiac MRI, and ventriculography are appointed for diagnosis. Treatment includes complex anticoagulant therapy and cardiac surgery.

General information

Intracardiac localization of blood clots is observed in 1-15.2% of people with cardiac diseases. This difference in statistics is due to the long asymptomatic course of the pathology and the difficulties of its instrumental diagnosis. Up to 90% of all cases are thrombi of the left auricle and atrium; less frequently, blood clots are in the left ventricle, right atrium, and ventricle. Intracardiac thromboses do not lose relevance in practical cardiology, as they are associated with life-threatening thromboembolic complications.

Causes

The development of intracardiac thrombosis is associated with the combined effect of two factors: a pathological increase in blood coagulation and the presence of structural and functional changes in cardiac cavities. Most cases of the disease occur in patients who suffer from other cardiac pathologies, which complicates the timely diagnosis. The main causes of intracardiac thrombus formation are:

• Arrhythmias. The leading provoking factor is atrial fibrillation (atrial fibrillation), in which the heart rate increases to 400-500 per minute. In fibrillation, there is stasis of blood in the left atrium, especially in its auricle, where most intracardiac blood clots are located.
• Acute coronary syndrome. The appearance of thrombi inside the heart chambers is characteristic of patients with myocardial infarction. The probability of pathology increases with anterior wall ischemia, a fall in the ejection fraction of blood less than 50%. The cause of intracardiac thrombosis is also postinfarction ventricular aneurysm.
• Heart defects. Structural anomalies of the heart chambers disturb the normal blood flow in the great and small circles, which becomes a trigger factor for thrombosis. Most often, pathology develops against the background of mitral valve stenosis, a typical complication of rheumatism.
• PE. The pathology is recognized as the leading cause of thrombosis in the right heart chambers. Intracardiac thrombi act as components of the systemic thromboembolic process. The risk of thrombosis is 4% in patients with non-massive PE and increases to 18% in the massive form of pulmonary embolism.
• Implantable devices. An increased risk of thrombosis is present in patients with a pacemaker, artificial valve, or central catheter. The probability of pathology increases with inadequately selected anticoagulant therapy and the presence of abnormalities in the results of coagulogram.

Symptoms of intracardiac thrombosis

Cardiac thrombi do not manifest themselves for a long time. Deterioration of health is associated with the underlying cardiovascular disease. Patients complain of heart palpitations, compression, pain in the left side of the chest, and dyspnea on exercise and at rest. Episodes of dizziness and fainting spells are possible. Blood flow disorders lead to hypoxia, which is manifested by weakness, headaches, and cognitive decline.

Complications

The main danger of intracardiac thrombosis is the spread of clots along the main vessels to the internal organs. If the clot is transported through the great circle of blood circulation, there is a risk of ischemic stroke, which occurs when one of the arteries supplying blood to the brain is blocked. Complications of intracardiac thrombosis of the left side of the heart include critical ischemia of the intestine, kidney, and lower extremities.

The involvement of the right chambers is associated with massive pulmonary thromboembolism. Critical blood flow disorders in the vessels of the bronchopulmonary system change the ventilation-perfusion ratio, cause arterial hypoxemia, and cause respiratory failure. At the same time, bronchospasm is formed, associated with increased synthesis of biologically active substances and aggravating respiratory disorders. PE may lead to the development of pulmonary infarction.

Diagnosis

A patient is examined by a cardiologist when referred for concomitant cardiac pathologies or thromboembolic complications. During the initial examination, attention is paid to the cardiac history, data from physical examination of the heart, and the presence of risk factors for cardiovascular crises. The following methods are used to diagnose intracardiac thrombus:

• Echocardiography. Classical transthoracic ultrasound of the heart has limited effectiveness. However, it allows you to detect signs of other pathologies and hemodynamic disorders. For accurate visualization of thrombus, transesophageal echocardiography is indicated. This gives the doctor information about the location, size, and attachment of the blood clot.
• Heart MRI. Magnetic resonance imaging is performed as an alternative to transesophageal ultrasound if the patient has contraindications to its performance. MRI provides clear and detailed images of all cardiac chambers, which is necessary to confirm intracardiac thrombosis and identify the preconditions for its development.
• ECG. Electrocardiography is necessary to identify signs of atrial fibrillation or other arrhythmia variants that act as a predisposing factor for thrombosis. The study is informative for rapid diagnosis of coronary syndrome and other complications of thromboembolism.
• Ventriculography. Examination of the heart cavities with contrast is an auxiliary invasive method necessary to visualize the contractile activity of the myocardium, the state of the heart valves, and structural anomalies of the heart. It is prescribed under strict indications, as it increases the risk of thromboembolism and arrhythmias.
• Blood tests. An expanded coagulogram is indicated to assess the blood system’s coagulation activity, including indicators of D-dimer and antithrombin III. In acute cardiovascular symptoms, myocardial markers and acute-phase indices are analyzed. Clinical and biochemical blood tests are performed to assess the patient’s general condition.

Differential diagnosis

Volumetric masses in the heart cavities detected by instrumental imaging should be distinguished from tumors. Differential diagnosis is performed with benign neoplasms – myxoma, rhabdomyoma, lipoma, papillary fibroelastoma, malignant processes – sarcoma, and metastases of breast, lung, and stomach cancer. It is also necessary to differentiate intracardiac thrombi from valve vegetations in infective endocarditis.

Treatment of intracardiac thrombosis

Conservative therapy

All patients are prescribed a program of anticoagulant and antiplatelet therapy, which is aimed at stabilizing the rheological properties of blood and preventing the progression and detachment of thrombus. Drugs are taken for life; their names and doses depend on the specific clinical situation. Vitamin K antagonists are used for the lysis of intracardiac thrombi, which contribute to the reduction or complete dissolution of the clot in 46-83% of patients.

Surgical treatment

Surgical intervention in cardiac surgery is justified when the course of intracardiac thrombosis is complicated or when the clots are significant, and there is a high probability of cardiovascular crises. The surgical tactics are selected individually, taking into account the location of the thrombus. To prevent intraoperative thromboembolism, the intervention is performed under cardiopulmonary bypass. In the case of thrombus detachment and vascular lesions, thrombectomy is indicated.

All these treatment options are available in more than 740 hospitals worldwide (https://doctor.global/results/diseases/intracardiac-thrombus). For example, Surgical ventricular restoration (SVR) can be done in these countries for following approximate prices:

Turkey $12.3 K in 26 clinics

Germany $46.8 K in 26 clinics

China $49.4 K in 4 clinics

Israel $67.6 K in 13 clinics

United States $74.0 K in 15 clinics.

Prognosis and prevention

Intracardiac thrombosis is a prognostic unfavorable factor, especially when combined with dangerous forms of arrhythmias and prosthetic valves. To prevent life-threatening complications, patients should be monitored by a cardiologist and have cardiac ultrasound controlled. Nonspecific prophylaxis aims to reduce the cardiovascular risk index and normalize lifestyle.