Cardiac Pacemakers are electronic devices placed in the body to correct the rhythm and conduction system disorders of the heart.
What are the Functions of the Heart?
The heart is a very important organ for our life. The circulation of the blood in our body and the nutrition of the tissues depend on the regular functioning of our heart. The heart consists of muscle tissue, about the size of a person's fist, and weighing half a kilo. It has four spaces. The two chambers at the top are called the right and left atrium (auricle), and the two chambers below are called the right and left ventricles. Between the right atrium and the right ventricle is the tricuspid valve. Superior and inferior main veins (Vena cava) open into the right atrium. Pulmonary artery emerges from the right ventricle.
Pulmonary valve is located at the mouth of the pulmonary artery. Between the left atrium and the left ventricle is the Mitral valve. Four veins (pulmonary veins) coming from the lungs open into the left atrium. The main artery arises from the left ventricle, the aorta. Between the left ventricle and the main artery is the aortic valve. Arteries carry oxygenated clean blood to our body. The pulmonary artery carries the dirty blood returning from the body to the lungs to be cleaned. The blood cleaned in the lungs returns to the left atrium and left ventricle via the pulmonary veins. The blood thrown from the left ventricle to the aorta and its branches reaches the whole body and our tissues are nourished in this way.
Blood circulates in our body with regular contraction and relaxation of the heart. During the contraction of the heart (systole), the blood in the heart is pumped into the arteries. During the relaxation and expansion of the heart (diastole) after the contraction, the blood returns to the heart through the veins. The pumping of the blood to the vessels by the contraction of the heart is called the heartbeat (pulse). Circulation rate is also provided by the heart according to the needs of our body.
Pacemakers (Cardiac Pacemakers)
Correction of conduction system disorders and especially bradycardia is vital. In order to correct bradycardia and perform daily activities better, instruments called pacemakers are attached to the body. pacemaker These are electronic devices consisting of two parts.
PULSE GENERATOR The part that generates a warning
LEAD or ELECTRODE The part that provides the message
Pulse generator consists of a battery and an electronic circuit. The battery is usually lithium. The electronic circuit is a small miniature computer. Various programs are installed. If desired, program changes can be made with the help of magnets. The energy from the battery turns into small electronic pulses and reaches the heart through the lead. The electronic circuit controls the timing and intensity of the electrical impulses transmitted to the heart.
Lead (=Electrode) provides the transmission between the heart and the Pulse generator. It is an insulated wire, usually made of polyurethane.
Pacemaker performs two important functions.
A - Stimulation To give a warning at the desired rate when there is no stimulation in the heart or when it is slow, B - PERCEPTION or FEELING Sensing the natural activity of the heart, monitoring it, and outputting a warning depending on the situation. . In other words, if the heart has its own rhythm, the pulse generator does not generate a warning. These conditions correct themselves. It is inserted to maintain the rhythm of the patient and to continue his life until it is healed.
It consists of a pacemaker box and a special lead. The lead is placed into the heart through a vein (from the neck, arm or groin). The other end of the wire is connected from the outside to the Pacemaker box. This type of temporarily placed pacemakers can be easily removed when the patient's condition improves.
2- Permanent Pacemaker: These pacemakers are permanently placed in the body.
Pacemaker is applied in two ways.
A - Endocardial route: Here, the electrode is passed through a vein. is placed in the heart. The procedure is performed with local anesthesia. B - Epicardial route: The electrode is attached directly to the heart muscle by suturing. This application is done with general anesthesia. It is rarely preferred in some cases where endocardial application cannot be performed. Local anesthesia is applied under completely sterile conditions. During the procedure, the doctor and assistant personnel should be kept sterile, as in the operating room conditions. They have a cap on their heads and a mask on their mouths. The anterior surface of the chest is cleaned with special solutions and sterile drapes are covered. The pacemaker is usually placed under the collarbone in the left chest (may be on the right side). By making measurements called threshold measurement, the state of the lead perceiving the stimulus and outputting the stimulus is checked. If appropriate, the leads are connected to the tissues and vein at the incision site. The other end of the lead is connected to the pulse generator, the generator is placed in a specially prepared pocket under the skin and the skin is closed. . Only one lead is used.
Two or Dual Chamber Stimulation: Both the right atrium and the right ventricle of the heart are stimulated. Two leads are placed in the right atrium and right ventricle.
Three-Chamber Bi-Ventricular Stimulation: It is a special form of stimulation used in Heart Failure. Three leads are placed in the right atrium, right ventricle and coronary sinus. In this case, the right atrium, right ventricle and left ventricle are stimulated.
Permanent pacemaker operation time is usually 1-2 hours. In some cases, the placement of the coronary sinus and the placement of the lead may take 3-4 hours in the insertion of three-chamber pacemakers.
What are the problems that may occur during permanent pacemaker insertion and what are the risks of the procedure?
It is a surgical procedure. During this application, there may be some undesirable situations, which we call some complications. Our hospital has a high experience in this field. Since 1989, more than 5000 patients have been successfully implanted with pacemakers. Complication rate is almost non-existent.
The rate of major vital complications is low in these interventions. 1-5%. This type of complications; Pericardial tamponade is pneumothorax and vascular injury.
Pericardial tamponade: lead placement is especially seen during the placement of twisted leads. The electrode enters between the heart's membrane, injuring and perforating the heart tissue. At this time, blood is collected between the pericardium leaves. According to the amount of fluid collected, the heart's function house is destroyed. The blood in the pericardium must be drained by puncture or surgically. Cardiac puncture during electrode placement is a very rare condition and usually occurs in heart failures where the heart tissue is very thin.
Pneumothorax: It is the puncture of the lung tissue during the search for the vein for the electrode to enter the heart. In this case, air fills into the pleura. It may be necessary to evacuate the air by attaching a tube from the outside. Sometimes, in minor injuries, the amount of air filled into the pleura is very small and is absorbed spontaneously without any intervention. Pneumothorax is generally seen in diseases such as COPD and emphysema, and in chest deformities. Sometimes the coronary sinus or its branches may be punctured, and in this case, blood collects around the heart and pericardial tamponade may develop. if there is no vein to pass through; (the vessel may be occluded or very thin or congenitally absent) the procedure can be repeated on the other side.
If no vessel is found, the electrode is surgically placed via the epicardial route.
In the first 1-3 months, the electrode may come out of the place where it was inserted in the heart. It needs to be corrected again.
What is a Shock Device (ICD=Implantable Cardiac Defibrillator)?
Abnormal rhythms arise from the heart, especially in vascular diseases and heart muscle diseases. These rhythms are very rapid and can be fatal if left uncorrected. These life-threatening rhythms are called Ventricular Tachycardia and Ventricular Fibrillation. During these rapid rhythms, the heart muscle cannot contract and relax.
These rhythms, especially Ventricular Fibrillation, can only be corrected with electric shock. This is why devices called ICD loyalty defibrillators are placed in the heart. Generators are a bit more complex due to their duties and their electrodes are specially made. These devices, which are slightly larger than normal pacemakers, are placed in the body like permanent pacemakers. These tools are also They also act as pacemakers.
What is Cardiac Resynchronization (CRT)?
Delays in electrical propagation in the heart are seen in Heart Failure Left Branch Block. Due to this electrical delay measured in seconds, the right and left ventricles of the heart cannot work in coordination and synchrony at the same time. The heart gradually deteriorates and heart failure worsens. To correct this situation, electrodes are placed in both the right and left ventricles of the heart. By means of these electrodes, the two sides of the heart work synchronously.
More information about these devices can be found in the Heart Failure section.
Caring for the patient with a pacemaker
After the pacemaker is inserted The wound site is closed and the patient is taken to the bed. Bed rest is required for the first 12 hours. The following days, wound care and chest radiography are taken and the location of the electrodes placed in the heart and the data of the pacemaker are checked.
According to the patient's condition; Usually, the patient is sent home in 2-3 days.
The shoulder on the side of the wound at home should not move much for 1 month. Except for the shoulder, the forearm and hand can be moved. It is not correct to attach the arm to the fixed body. The arm should be free and only shoulder movements should be restricted. Wound care should be done by your doctor in the first 1 week follow-up. The patient's identification information and pacemaker information are written on this card. This information is recorded and monitored by both the Social Security department and the main unit of the Pacemaker company. Patients are required to carry this card with them at all times.
Pacemakers are electronic devices. There is an electromagnetic field around the tools that contain magnets that work with electricity. These areas are usually weak and do not affect your pacemaker. However, strong electromagnetic fields cause electromagnetic interference. This may temporarily impair the function of your pacemaker. It can put you in a difficult situation, albeit temporarily.
Especially at the airport and some buildings.
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