I wonder if you have ever wondered why the heart can beat spontaneously so miraculously? In fact, this is related to the electrical conduction of the heart. The beating of the heart is actually the contraction and diastole of the myocardium. The myocardium is tense when contracted and relaxed when it is relaxed. This pushes the blood flow in a “squeeze” process. Myocardial contraction has a lot in common with the contraction of other muscles in the human body. It relies on the weak current stimulation produced by the organism itself. In fact, most heart regions have the ability to generate electrical signals and electrical impulses, but they must all obey a supreme “leadership”-the sinus node.
The sinus node in the upper left corner of the heart produces and emits impulses at the fastest frequency, between 60 and 100 beats/min. This can suppress impulses in other areas of the heart and become the pacemaker of the entire heart. If you see the word “sinus rhythm” on the electrocardiogram, it means that the heart rhythm is sent by the sinus node, and the heart’s command system is not confused.
The conduction of these signals depends on a complete set of cardiac conduction system, and the circuit in this system has a problem, which is called conduction block. For example, sinus block means that after the sinus node sends a signal, the speed of transmission to the surrounding atrial tissue slows down, thus causing a long heartbeat interval. Atrioventricular block is a conduction block between the atrium and the ventricle. The problem may lie in the atrioventricular node or the circuit that conducts from the atrioventricular node to the lower ventricle-left bundle branch, right bundle branch, left anterior branch, left posterior branch Wait.
〇Heart block, a disease in which working cells are reduced
Director Sun told us that heart block is essentially a disease in which working cells are reduced. The sinoatrial node and other conductive tissues are composed of clusters of working cells, and they also rely on these cells to send out and conduct impulses. When these cells die or decrease due to some reasons, and their ability to send out and conduct impulses decreases, conduction block occurs.
The more common cause is aging of the heart, which is more common in elderly patients. “Young people with heart block should first consider whether there is a risk of myocarditis.” There are also some long-term patients with kidney disease and diabetes. Their heart microvessels have disease, which affects the blood supply of tissues, and may also lead to the occurrence of this disease.
“In general, the conduction block that occurs between the sinuses is usually benign, it is not harmful, and the risk of sudden death is small. If an atrioventricular block occurs, the risk of sudden death is relatively high, and it requires strict attention and activeness. Seek medical attention.”
〇 Electrocardiogram-the main inspection method
The incidence of heart block is not high. According to foreign data, Director Sun estimates that the incidence of heart block in my country is 3% to 5%. However, due to the huge population base of our country, the number of patients with heart block and potential patients will be a huge number. This disease is more likely to be caused by the aging of the heart, so the incidence rate in the elderly population will be higher. At the same time, if the condition is not serious, there will often be no obvious symptoms, which makes many people not aware of the existence of the disease.
“Relatively speaking, the discovery of this disease is still not difficult. It can be found mainly through single-shot and dynamic electrocardiogram.” Now the ECG examination is very convenient, and most physical examinations will include ECG items. However, if the condition is not serious, or the ECG did not occur during the ECG examination, the ECG examination for only about 10 seconds may miss the abnormal heart rhythm performance. “Many patients have abnormal heart rhythms during night sleep, often at 2 in the morning, so that a single ECG will definitely not be found. A 24-hour dynamic ECG examination is required.”
〇The only effective treatment-pacemaker implantation
For this type of working cell reduction disease, there is currently no specific drug to treat, and the most effective and only clinical treatment at present is to install a pacemaker. “At present, for severe conduction block, which is generally 2 degrees or above, and clinical symptoms appear, the main treatment method is implantation of a pacemaker. This is currently the only treatment method that has been confirmed to be effective and has good long-term safety for patients. .” Director Sun introduced.
There are two types of pacemakers, temporary and permanent. People rarely come into contact with temporary pacemakers, and they mainly play the role of “escorting”. Director Sun told us that some patients have bradycardia caused by heart block, but they have not yet reached the point where a permanent pacemaker needs to be implanted. Temporary pacemakers are used when patients encounter high-risk scenarios such as anesthesia and surgery. Escort. If the operation is over and the anesthesia is removed, the temporary pacemaker will be taken out.
If the patient meets the indications for permanent pacemaker implantation, then they may need to be accompanied by a permanent pacemaker in the future. Permanent pacemakers are divided into two types: with lead and without lead. At present, pacemakers with lead wires are most commonly used in clinical practice. The technology is very mature, and the material of lead wires and equipment performance are very stable. However, the wires connecting the inside and outside of the human body may increase the risk of infection within 3 to 6 months after implantation.
The leadless pacemaker is a new variety that has emerged in the past 5 years. The biggest advantage is that without that long wire, the life of the patient is more convenient and the risk of infection is relatively small. But it also has certain shortcomings. “This kind of pacemaker is difficult to take out after it is put in, and it must be removed through surgery. At the same time, the service life is not as good as that of a pacemaker with a lead.”
〇Pacemaker implanters must avoid strong magnetism
Patients with pacemakers do not need to worry about the inconvenience of life. Director Sun told us that after the pacemaker is implanted, the life of patients is basically the same as that of ordinary people, and their daily lives will not be affected.
However, for all types of pacemakers, it is necessary to avoid high-intensity electromagnetic interference. This is mainly because electromagnetic interference may affect the performance of the pacemaker. Although the pacemaker will not be directly scrapped, it may affect its working state and cause it to gradually malfunction, causing unnecessary risks. Director Sun told us that the strong magnetic environment that normal people can access is mainly magnetic resonance examination, and patients with pacemaker implants cannot accept magnetic resonance examination in principle unless they have very necessary reasons.
In daily life, the main things to avoid are magnets and security equipment. “The metal detection doors used in airports, high-speed railway stations and some subways are also highly magnetic, which has a certain impact on pacemakers. We will advise patients to bring identification cards with disease certificates. You can show it at time and switch to a manual security check.” Some patients may have the habit of disassembling electronic devices and playing with magnets. If a pacemaker is implanted, it should be avoided.
As for the magnetic fields in life that many patients worry about, such as the magnetic fields of household appliances such as microwave ovens, high-power equipment of high-speed railways and airplanes, and the magnetic fields of communication equipment such as mobile phones and communication base stations, Director Sun believes that there is no need to worry. “The magnetic force of these devices is very weak, and normal use will not affect the pacemaker. There is no problem in taking high-speed trains or airplanes.”
〇Exercise is beneficial but not effective for treatment
We all know that the heart rate can rise during exercise. Can exercise improve this disease characterized by slow heartbeat? actually not. Director Sun emphasized that exercise itself does not have a clear therapeutic effect on organic diseases such as conduction block. On the contrary, excessive and large amounts of exercise will increase the risk of patients.
Regardless of whether a pacemaker is implanted or not, strenuous exercise should be the first thing patients with heart block should avoid, which may increase the risk of cardiac arrest and sudden death. “The main reason is that after the exercise intensity reaches a certain level, especially after the body’s hypoxia reaches its peak, the heart needs high-intensity and violent contractions to cope with it. If the heart has a conduction block problem, it may be in this case. Live, it’s like the engine stalls, which may cause sudden death.” Director Sun introduced.
However, moderate exercise is beneficial for improving cardiopulmonary function and improving the body’s ability to withstand ischemia and hypoxia. It can help the body to better cope and tolerate when the heart rate slows down. It is recommended to perform low- and medium-intensity aerobic exercises, such as swimming, walking, jogging, etc. Strenuous anaerobic exercises, such as high-weight strength training, must be avoided.
〇Learn to take the pulse and monitor in time
In many cases, you don’t need complicated equipment to judge your heart rate, you only need to learn a simple skill-pulse taking. The most commonly used are the radial artery and carotid artery of the wrist. However, it is not recommended for the elderly to use the carotid artery to determine the pulse. There is a carotid sinus near the carotid artery. Pressing stimulation may cause hypotension and syncope. When the patient feels heart discomfort, the first thing is to take the pulse and count his pulse. Of course, it would be better if you use a heart rate wristband to detect it every day. It takes 10 to 15 seconds to feel the pulse, and multiply it by the corresponding number to get the number of heartbeats in one minute.
Director Sun believes that for patients with conduction block, the most important concept in daily life is to pay attention to their own heartbeat, and if there is discomfort or abnormal heart rate, seek medical treatment in time.