The coronary sinus is the largest vein of 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 a thorough study of the coronary sinus and its tributaries.
Basic anatomy
This is a wide channel - about 2-5.5 cm long with a hole of 5-15 mm in diameter. It has an endocardial fold, which is called the Tibesia flap. It is the tail of the right flap of the embryonic sinus opening. Located in the diaphragmatic part of the coronary groove.
Physiology
The coronary sinus is formed by connecting the large cardiac vein and the main posterior lateral vein. The first passes through the interventricular groove similarly to the left anterior descending artery. Other main tributaries of the coronary sinus are the lower left ventricular and middle cardiac veins. The atrial myocardium also flows into it through various atrial vessels and veins of Tibesia.
Embryology
During intrauterine development, a single tube of the heart gives rise to the primary atrium and sinus venosis. By the fourth week of pregnancy, the three main paired systems of the embryo - cardinal, umbilical and ventricular, merge into sinus venosis. During the fourth week, intussusception occurs between its left flow and the left atrium, ultimately separating them. When the transverse segment of the sinus venosis shifts to the right, it pulls the left flow along the posterior ventricular groove. Cardiac veins and coronary sinus form.
Value
There are two separate functions. First, it provides a myocardial drainage route. Secondly, it offers an alternative way of eating it. The role of the coronary sinuses is to collect venous blood from the cardiac cavities. The coronary sinus collects 60-70% of cardiac blood. It is of great interest in cardiac surgery and is used for:
- retrograde pacemaker;
- with extra-telecirculation;
- radiofrequency ablation of ear tachycordia;
- 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 stimulants are introduced inside the tribal branches to stimulate the left ventricles;
- diagnostic conductors are placed in it for recording electric potentials during endocavitary electrophysiological research;
- in tributary branches, trans-catheter ablation of the left ventricular tachycardia can be performed;
- ablation of auxiliary beams is carried out in it;
- it may contain conductors for stimulation of the left atrium, useful for the prevention of atrial fibrillation;
- it is an anatomical find for puncture of the interventricular septum.
Defects
Within a significant amount of information related to congenital heart defects, abnormalities associated with the coronary sinus received relatively little attention. Although some of them can be of great importance. They can 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 abnormality is the expansion of the coronary sinus. It can be divided into two broad groups based on the presence or absence of a shunt in the heart.
The next anomaly is the absence of a coronary sinus. It is always associated with a permanent connection of the left superior vena cava with the left atrium, atrial septal defect, and other additional disorders. It usually has a shunt from right to left at the level of the right atrium as part of a complex functional abnormality.
Another defect is atresia or stenosis of the right coronary sinus. In this case, abnormal venous channels serve as the only route or main collateral outflow of blood.
Valsava sinus aneurysm
This pathological extension of the aortic root is also called a coronary sinus aneurysm. Most often found on the right side. It 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 connective tissue diseases. It is associated with bicuspid aortic valves. The acquired form can occur a second time with chronic changes in atherosclerosis and cystic necrosis. Also, causes may be a chest injury, bacterial endocarditis, tuberculosis.
Sinus node weakness syndrome
The term was coined in 1962 by American cardiologist Bernard Lown. A diagnosis can be made if at least one of the typical results on an electrocardiogram has been demonstrated:
- inadequate bradycardia of the coronary sinus;
- fading of the sinus node;
- sinoatrial block;
- atrial fibrillation;
- atrial flutter;
- supraventricular tachycardia.
The most common cause of sick sinus syndrome is arterial hypertension, which leads to a chronic load on the atrium, and then to excessive stretching of the muscle fibers. The key examination method is a long-term ECG.
Pathology
The coronary sinus can be affected by cardiopathies and diseases that violate 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 that affects the coronary sinus. It causes organ dysfunction, which 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 are destroyed and die. This leads to cardiac dysfunction and cardiac arrest. Myocardial infarction is manifested by rhythm disturbance and insufficiency.
- Angina pectoris. This pathology corresponds to depressing and deep pain in the chest. Most often this happens during stress. The cause of pain is the improper supply of oxygen to the myocardium, which is often associated with pathologies that affect 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 examination. It takes place in several stages:
- Clinical examination. It is performed to study the rhythm of the coronary sinus and to evaluate symptoms such as shortness of breath and rapid heartbeat.
- Medical checkup. To establish or confirm a diagnosis, cardiac or Doppler ultrasound can be performed. They can be supplemented with coronary angiography, CT and MRI.
- Electrocardiogram. This examination allows you to analyze the electrical activity of the body.
- Electrocardiogram stress. Allows you to analyze the electrical activity of the heart during physical exertion.