The main indications for pacemakers are pathological sinus node syndrome and atrioventricular block. In most cases pacemakers are intended for people whose heart rate is too slow to cause discomfort. Pacemakers should be implanted when the heart stops for more than 3 seconds or when the heart rate frequently falls below 40 beats, especially in patients who experience blackouts and sudden fainting. This is the primary and initial therapeutic category of pacemakers. In addition, pacemakers can treat and prevent many diseases. For example, a heart attack can cause the heart muscle to fail to contract forcefully. The reduced contraction of the heart causes the heart to under-pump, resulting in various symptoms such as dizziness, chest tightness, and weakness. For example, in cases of congestive heart failure and severe hypertrophic obstructive cardiomyopathy where medication has failed, multiple pacing electrodes can be installed in various parts of the heart to synchronize multiple electrical stimulation commands to help the heart muscle contract. Meanwhile, some diseases can trigger cardiac arrest or fatal malignant ventricular arrhythmias (e.g., rapid ventricular tachycardia, ventricular fibrillation), and pacemakers with defibrillator function can be installed, which can restore the regular beating of the heart. In addition to this, pacemakers are also indispensable or the only treatment in the comprehensive treatment of certain heart diseases (carotid sinus hypersensitivity syndrome, vasovagal syncope, idiopathic Q-T prolongation syndrome, prevention of rapid atrial arrhythmias, etc.). Treatment of slow heartbeat If you are easily fatigued, tired, or lethargic, feel uncomfortable with your heartbeat or have dizziness, blackness, or even fainting, you may have a slow heartbeat and should see a cardiologist. Slow heartbeats are usually treated with medication and pacemakers. There are no specific medications for chronic tachycardia. Numerous clinical studies have confirmed that pacemaker implantation is the most effective way to treat slow heartbeat. Cardiac pacing technology has been used for more than half a century and has saved the lives of numerous patients with slow heartbeats. A slow heartbeat can be caused by a lesion in the heart’s command unit (medically known as the sinus node) and/or an obstruction in the conduction of the heartbeat’s commands. Our whole body depends on the contraction of the heart to pump oxygen and nutrients. A slow heartbeat causes low pumping function or a transient stop, which results in a series of symptoms of hypoxia, such as dizziness, vertigo, darkness, syncope, memory loss, fatigue, weakness, activity The symptoms include dizziness, vertigo, black haze, syncope, memory loss, fatigue, weakness, reduced activity endurance, chest tightness, panic, shortness of breath, etc. In severe cases, fainting or death may occur. If the above symptoms are transient, or if the symptoms are not very obvious, but the examination has revealed an objective basis of significant cardiac arrest and atrioventricular block, rapid and slow heartbeat, most patients need pacemaker therapy. In addition, if the patient has to take certain medications that slow down the heart rate and his or her own heartbeat is slow, then a pacemaker may also be needed to protect the heart. Treatment of advanced refractory chronic heart failure With the rapid development of medical technology, pacing technology is changing rapidly and pacing therapy is no longer limited to patients with slow heartbeats. Some pacemakers can also treat refractory chronic heart failure by improving heart function through biventricular synchronous pacing. Biventricular synchronized pacing (abbreviated as CRT) can treat heart failure by restoring the synchronized beating of the right and left ventricles. The prevalence of chronic heart failure in adults in China is about 0.9%, and it is estimated that there are about 5 million patients with heart failure nationwide. Drug therapy has made great progress in recent years and is the basic treatment for heart failure, but there are still poor or ineffective patients, while heart transplant donors are limited and costly. Pacing therapy is developing rapidly and is an effective complementary tool for the treatment of advanced chronic heart failure. CRT-type pacemakers are mainly aimed at patients with chronic heart failure in which the left ventricle is greater than 55, the cardiac output is less than 35%, and the left and right ventricular contractions are not synchronized, allowing the left and right ventricular contractions to be unsynchronized and improving a series of problems with worse cardiac function and less effective blood ejection. Treatment of rapid malignant ventricular arrhythmias Pacemaker technology can save the patient’s life in time in case of severe slow heart rate, and CRT-type pacemakers are an effective treatment for severe refractory chronic heart failure. However, for many heart diseases such as coronary myocardial infarction and dilated cardiomyopathy, patients are not only exposed to the problem of heart failure but also to the risk of sudden onset of rapid ventricular malignant arrhythmias (sustained ventricular tachycardia, ventricular fibrillation), and about 30% of patients with chronic heart failure die from sudden death due to malignant ventricular arrhythmias. Patients with coronary angina pectoris, myocardial infarction, cardiomyopathy, refractory heart failure, and other patients at high risk for malignant tachyarrhythmias, such as ventricular tachycardia or ventricular fibrillation, as well as those with a family history of hereditary malignant arrhythmias and sudden cardiac death, need to be fitted with special pacemakers with resuscitation and defibrillation (ICDs for short) to prevent sudden cardiac death. If better conditions are available, installation of a CRTD is recommended to address both the treatment of heart failure and the prevention of malignant arrhythmias. Pacemaker installers should stay away from strong magnetic fields In daily life, most home appliances, such as electric shavers, TV sets, vacuum cleaners, ovens, etc., do not interfere with the work of pacemakers, and patients can travel safely in cars and airplanes, etc. However, patients should stay away from strong electromagnetic fields, such as radar stations, high-voltage transformers, welding machines, electromagnetic machines, etc. They should not use the side of the ear where the pacemaker is placed to receive cell phones, and should not undergo MRI examinations. At the same time, patients with pacemakers mostly suffer from coronary heart disease, hypertension and other diseases, so the treatment of the original disease should not be neglected after the pacemaker is installed. In fact, patients with pacemakers can also suffer from angina pectoris, myocardial infarction and heart failure. Therefore, it is important not to be paralyzed and to take medication for the primary disease as prescribed by the doctor. It should be reminded that patients who have been discharged from the hospital with a pacemaker should carry with them an emergency card with their name, age, contact address, date and type of pacemaker installation, etc., so that the doctor can be informed of the pacemaker’s condition in case of an emergency.