The coronary sinus is the largest vein in the heart. It is the least studied compared to its arterial counterpart due to vital interventional approaches through the coronary artery. Most modern procedures in electrophysiology require an in-depth study of the coronary sinus and its tributaries.
Basic Anatomy
This is a wide channel - about 2-5.5 cm long with a hole 5-15 mm in diameter. It has an endocardial fold called the Tibesian valve. It is the caudal part of the right valve of the embryonic sinus opening. Located in the diaphragmatic part of the coronary sulcus.
Physiology
The coronary sinus is formed by the connection of the great cardiac vein and the main posterior lateral vein. The first passes through the interventricular groove, similar to the left anterior descending artery. The other main tributaries entering the coronary sinus are the inferior left ventricular and middle cardiac veins. The atrial myocardium also drains into it through various atrial vessels and the veins of Tibesia.
Embryology
During fetal development solitaryThe heart tube gives rise to the primary atrium and the sinus venus. By the fourth week of pregnancy, the three main pair systems of the embryo - the cardinal, umbilical and ventricular, merge into the sinus venosis. During the fourth week, an invagination occurs between its left stream and the left atrium, eventually separating them. When the transverse segment of the sinus vein shifts to the right, it pulls the left stream along the posterior ventricular groove. Cardiac veins and coronary sinus are formed.
Meaning
There are two separate functions. First, it provides a myocardial drainage route. Secondly, it offers an alternative way to feed it. The role of the coronary sinuses is to collect venous blood from the heart cavities. The coronary sinus collects 60-70% of cardiac blood. It is of great interest in cardiac surgery and is used for:
- retrograde pacing;
- with extra telecirculation;
- radiofrequency ablation of ear tachycordias;
- creating a prosthesis in mitral valve surgery.
Benefit
With the development of new interventional treatments, the coronary sinus has become an important structure. Its benefits are as follows:
- Electrocatheter stimulators are inserted inside the tribal branches to stimulate the left ventricles;
- diagnostic conductors are placed in it for recording electrical potentials during endocavitary electrophysiological examination;
- trans-catheter can be performed in tributary branchesablation of left ventricular tachycardias;
- ablations of auxiliary beams are carried out in it;
- it can accommodate left atrial pacing leads, useful for preventing atrial fibrillation;
- he is an anatomical finding for ventricular septal puncture.
Defects
Within the considerable body of information related to congenital heart disease, anomalies associated with the coronary sinus have received relatively little attention. Although some of them can be of great importance. They may be isolated and harmless, but they can also be a component of various serious malformations. Failure to recognize such defects can lead to serious surgical problems.
The most common anomaly is the expansion of the coronary sinus. It can be divided into two broad groups based on the presence or absence of a bypass in the heart.
The next anomaly is the absence of the coronary sinus. It is always associated with a permanent connection of the left superior vena cava with the left atrium, an atrial septal defect, and other additional disorders. Usually has a right-to-left shunt at the level of the right atrium as part of a complex functional anomaly.
Another defect is atresia or stenosis of the right coronary sinus. In this case, the abnormal venous channels serve as the only route or main collateral outflow of blood.
Aneurysmsinus of Valsava
This abnormal enlargement of the aortic root is also called a coronary sinus aneurysm. Most often found on the right side. Occurs as a result of weak elasticity of the plate at the junction of the aortic medium. The normal sinus diameter is less than 4.0 cm for men and 3.6 cm for women.
Aneurysm of the coronary sinus can be either congenital or acquired. The first may be associated with diseases of the connective tissue. It is associated with bicuspid aortic valves. The acquired form may occur secondary to chronic changes in atherosclerosis and cystic necrosis. Other causes include chest trauma, bacterial endocarditis, tuberculosis.
Sick sinus syndrome
The term was coined in 1962 by American cardiologist Bernard Lown. The diagnosis can be made if at least one of the typical findings on the electrocardiogram has been demonstrated:
- inadequate coronary sinus bradycardia;
- sinus node fading;
- sinoatrial block;
- atrial fibrillation;
- atrial flutter;
- Supraventricular tachycardia.
The most common cause of sick sinus syndrome is arterial hypertension, which leads to chronic stress on the atrium, and then to excessive stretching of the muscle fibers. Long-term ECG is the key examination method.
Pathologies
The coronary sinus can be affected in cardiopathies and diseases,disturbing the functions of the heart. In most cases, these diseases are associated with pathologies of the coronary arteries. The most common ones are:
- Abnormal venous return. This rare pathology corresponds to a congenital malformation affecting the coronary sinus. It causes organ dysfunction that can lead to heart failure.
- Myocardial infarction. Also called a heart attack. It corresponds to the destruction of part of the myocardium. Oxygen-deprived cells collapse and die. This leads to cardiac dysfunction and cardiac arrest. Myocardial infarction is manifested by rhythm disturbance and insufficiency.
- Angina. This pathology corresponds to depressing and deep pain in the chest. Most often this happens during times of stress. The cause of the pain is an improper supply of oxygen to the myocardium, which is often associated with pathologies affecting the coronary sinus.
Coronary sinus examination
For the timely adoption of measures for the treatment of various pathologies of the coronary veins, it is necessary to undergo regular examinations. It goes through several stages:
- Clinical examination. It is performed to study the rhythm of the coronary sinus and evaluate symptoms such as shortness of breath and palpitations.
- Medical examination. A cardiac or Doppler ultrasound may be performed to establish or confirm the diagnosis. They can be supplemented by coronary angiography, CT and MRI.
- Electrocardiogram. This survey allows us to analyzeelectrical activity of the organ.
- Electrocardiogram of stress. Allows you to analyze the electrical activity of the heart during exercise.
