1.How is the contraction of the heart accomplished?
In a normal heart, the highest “command” that controls the contraction of the heart is called the sinus node, which sends electrical impulses at a certain frequency and rhythm according to the needs of the body. The electrical impulses from the sinoatrial node are then transmitted to the left and right atria along a specific pathway (called the conduction pathway in medical terms). The electrical impulse then travels to the atrioventricular node, which is the hub and only pathway for the conduction of electrical impulses between the atria and ventricles. The atrioventricular node is the “relay station” for the conduction of electrical impulses between the atria and ventricles. After the electrical impulse passes through the atrioventricular node, it then causes the left and right ventricles to contract almost simultaneously through the left and right bundle branches and the terminal pathway, thus completing a cardiac ejection.
2. What are the conditions for pacemaker installation?
Abnormal electrical activity of the heart, i.e. too little electrical activity or poor conduction lines can cause the heart to beat too slowly. Poor conduction between the two atria can produce atrial conduction block, and poor conduction between the two ventricles can lead to asynchronous contraction of the two ventricles. Simply put, the heart beats faster when there is more electrical activity and slower when there is less electrical activity. Faster does not work, and slower does not work either.
A common condition that requires a pacemaker is a slow heartbeat that causes severe symptoms in the brain, heart and other vital organs, such as dizziness, weakness, memory loss, blackness in front of the eyes when walking or moving, and in severe cases, sudden confusion. The most common diseases that cause these conditions are: atrioventricular block and sick sinus node syndrome (sick sinus syndrome for short).
3. What is the structure of a pacemaker?
The pacemaker consists of two parts: the simple pacemaker (pulse generator) and the electrode lead. According to the designed procedure, the pacemaker is responsible for issuing electrical signals, which pass through the electrode leads and stimulate the myocardium, which generates mechanical activity (heart contraction and diastole) according to the signals transmitted by the electrode leads. The pacemaker emits an electrical signal and is a life-saving device that triggers the heart to beat.
4. How is a pacemaker installed?
Generally, the pacemaker is buried under the skin in the anterior chest, and the electrode leads connecting the pacemaker to the heart muscle travel through the blood vessels. With the development of electronic computer technology, various intelligent pacemakers with high-tech performance have been used in clinical practice. The pacemakers used in recent years tend to be more miniaturized and physiological.
5.What are the types of pacemakers?
Artificial pacemakers are divided into atrial and ventricular pacemakers according to whether the electrode leads are placed in the atria or the ventricles; physiological and non-physiological pacemakers according to the effect on heart function; and single-chamber and dual-chamber pacemakers according to the number of electrode leads implanted in the heart chambers. There are also triple-chamber pacemakers for patients with severe heart failure. In addition, there are also pacemakers with special functions and roles, such as the in vivo buried automatic defibrillator (ICD) for the treatment of ventricular fibrillation.
6. What should I pay attention to before the pacemaker procedure?
Go to the hospital for relevant preoperative examinations. These include: routine blood tests, coagulation function, liver and kidney function, and other routine tests. In addition, there are other tests related to this procedure, including echocardiography, chest x-ray, and electrocardiogram. Patients with pacemakers in particular should have an ambulatory electrocardiogram (Holter), which is an important guide to evaluate whether a pacemaker is needed and what type of pacemaker to install. After admission, local skin preparation and antibiotic skin testing should also be done before surgery. The doctor will talk in advance before the procedure, and must get the consent form for the interventional procedure signed by the patient and the family, and explain in detail to the family the necessity and possible risks of the procedure, and answer questions from the family and the patient.
If you are taking drugs that have an effect on coagulation and hemostasis, such as aspirin, it is best to stop using these drugs 3-5 days before the procedure, otherwise it may increase the risk of bleeding and infection in the pacemaker capsule after the procedure.
7. Is the implantation of a pacemaker dangerous?
The pacemaker installation (implantation) procedure is a minor surgery and risks exist, but the procedure itself is safe and is performed with the patient fully awake. In most cases, the pacemaker is mounted on the left or right anterior chest.
8. What is the pacemaker implantation procedure?
Once the patient enters the catheterization room, he or she removes the shirt and lies down on the surgical bed, and the surgeon begins disinfecting the anterior chest and placing the surgical towel (sheet). The procedure is usually performed under local anesthesia and the skin is incised, with an incision usually about 4 to 6 cm long. The surgeon then makes the capsular bag into which the pacemaker pulse generator will be placed. The pacemaker electrode leads are inserted into the intended cardiac chambers by puncturing the subclavian vein or by incising the cephalic vein to find a suitable electrode placement site. After a suitable pacing position is found, the electrode lead is fixed and the desired electrophysiological parameters are measured. The electrode lead is then connected to the pulse generator and buried in the capsule that has been created. After determining the appropriate position of the electrode lead in the heart, the skin is sutured and the wound is dressed.
9. What are the precautions after pacemaker implantation?
After pacemaker implantation, the patient should generally be placed in a flat position with minimal activity in the early post-operative period (within 24 hours), and can get out of bed after 24 hours. During this period, you should avoid drastic and strenuous activities on the side of the implanted limb and eat a diet based on easily digestible food.
Because most pacemakers are installed in the right upper chest wall, near the right upper limb, many patients are afraid to move around, and some even suffer from frozen shoulder and shoulder joint adhesions as a result. The correct method is: when you can sit up or can move around after surgery, especially after the removal of stitches, you can perform light and appropriate upper limb and shoulder joint activities. After discharge from the hospital, you can perform physical exercise according to your physical strength, as long as you do not feel excessively fatigued or short of breath, and avoid strenuous right upper limb activities. In addition, cardiac monitoring is often required for at least 24 hours after returning to the ward after pacemaker implantation.
After pacemaker implantation, patients should not come into contact with leaking electrical appliances, electromagnetic fields near extremely high-voltage transmission lines, or high-powered electrical equipment. Do not move the pacemaker’s limb excessively, and do not use heavy objects to compress the pacemaker wires. Do not touch or massage the pacemaker site frequently.
10. Can I use my cell phone after the pacemaker is installed?
After the pacemaker is installed, please keep the cell phone at a distance of 22 cm or more from the pacemaker implantation site. It is recommended to answer the cell phone with the ear on the side without the pacemaker; it is better to carry it in your lower jacket pocket or at your waist.
11. What are the follow-up visits after pacemaker installation?
Patients with heart disease should not think that everything is fine after the pacemaker is installed. Because the patient may experience one or another discomfort in the early stages of pacemaker installation, it is usually a good idea to see the doctor for a follow-up visit once every three months within a year of the pacemaker installation. The doctor will adjust the pacemaker parameters according to the adaptation of the patient’s heart. After that, the patient should be followed up once a year. When the warranty period of the pacemaker is about to expire, the patient should visit the hospital more often to find out if the pacemaker’s battery power has decreased in time to determine when the pacemaker should be replaced. In addition, treatment of the underlying heart disease should be maintained.