What Is Interventricular Septum?
Most are composed of the myocardium, called the muscle; the upper part is followed by an irregular membrane tissue, called the membrane, which is the most common site of ventricular septal defect.
- Chinese name
- Ventricular septum
- Foreign name
- Interventricular septum
- Department
- Cardiology
- Most are composed of the myocardium, called the muscle; the upper part is followed by an irregular membrane tissue, called the membrane, which is the most common site of ventricular septal defect.
Anatomy of a ventricular septum
- The common inner wall of the left and right ventricles, or the ventricular septum. Most are made up of the heart muscle, called pars muscu-laris septi interventricularis. Both sides of the ventricular septum are covered by the endocardium. The interventricular septum is about 2 to 8 mm thick, and the thicker it is near the apex. However, there is a small oval-shaped area in the upper part, which is very thin and lacks muscle mass. It is called parsmembranacea septi interventricularis. The left side of the membrane is located below the right aortic valve and the posterior valve, and the right side is often divided into upper and lower parts by the attachment edge of the tricuspid valve. The upper part divides the right atrium and the left ventricle, called the pars interventricularis; the lower part divides the left and right ventricles, called the pars interventricularis. The ventricular septal membrane is a common site of ventricular septal defect. The ventricular septum is triangular in shape, with the bottom located above and the top corresponding to the apex of the heart. It is marked on the surface of the heart as anterior and posterior ventricular grooves. The ventricular septum is also in a frontal position, and then twists downward in a clockwise direction to the apex of the heart. The anterior part is more curved and the posterior part is more straight. This twist causes the ventricular septum to form a large convex surface in the right ventricle, convex toward the right ventricle, and concave toward the left. The upper two sides of the ventricular septum are smooth, but the sides near the apex of the heart are not smooth, especially the right side, which is approximately sponge-like.
Ventricular septal defect
- Ventricular septal defect is a common congenital heart disease caused by ventricular septal hypoplasia. It can exist alone or form part of a congenital compound heart malformation such as tetralogy of Fallot. According to its pathological anatomy, it can be divided into supractistal ventricular septal defect; in-fracristal ventricular septal defect; inflow tract-type ventricular septal defect (ventricalar septal defect of inflow tract); ventricular septal defect of AV commontract (4 types). The defect diameters ranged from 0.2 to 3.0 cm. If the diameter of the defect is greater than 3.0cm, it is called a giant ventricular septal defect. In ventricular septal defect, the left ventricular pressure is higher than the right ventricle during ventricular systole, so blood flows from the left ventricle to the right ventricle. The amount of shunt depends on the size of the defect, compliance of the right ventricle, and resistance to the pulmonary circulation. With the worsening of the condition, if the pulmonary circulation resistance increases to equal to or higher than the systemic circulation, a bidirectional or right-to-left shunt appears and cyanosis appears. The patient's symptoms depend on the size of the defect and may be asymptomatic or palpitations, asthma, cough, fatigue, etc. after exertion. Late course may have heart failure, cyanosis and cardiac block. Signs are mainly 3 to 5/6 intercostal murmurs of the left margin of the sternum. Levels 3 to 5/6 are loud and rough systolic murmurs, which are often accompanied by tremors, and P2 are mostly hyperthyroidism; those with pulmonary hypertension, systolic murmur Reduced, but P2 hyperthyroidism was more pronounced. X-ray examination mostly showed thickening of pulmonary blood vessels, pulmonary congestion, and increased heart shadow. ECG manifestations can be left ventricular hypertrophy, right ventricular hypertrophy, or hypertrophy in the right ventricle, or normal ECG. Echocardiography showed interrupted ventricular septal echo, and Doppler showed shunting. Examination of the right heart catheter showed that the blood oxygen content of the right ventricle was higher than that of the right atrium by 0.9 vol / dl or more. Selective left ventricular angiography shows simultaneous visualization of left and right ventricles. Common complications of this disease include infective endocarditis, pulmonary hypertension, heart failure, and arrhythmia. Patients with surgical indications for this disease need timely repair of the defect under extracorporeal circulation. Patients with mild ventricular defects can also postpone surgery. Patients with severe pulmonary hypertension should not be treated surgically. The appropriate age for surgery is 2 to 14 years. Medical treatment is mainly to follow up the changes of the disease and prevent complications. Those with small defects naturally have a good prognosis, and may be closed before school age; those with large defects can develop heart failure in infancy; those with pulmonary hypertension have a poor prognosis; those with surgical correction can have improved prognosis.