Where are the two locations for defibrillation?

In today's society, people face various stress problems in their lives. The body is also prone to different disease symptoms. The defibrillation site is an ill-defined area. But symptoms of illness often occur for a variety of reasons. It is necessary to have a specific understanding of the situation of this area in order to provide targeted treatment. Where are the two defibrillator locations?

1. Asynchronous defibrillator. This type of defibrillator is not synchronized with the patient's own R wave during defibrillation and can be used in ventricular fibrillation and flutter (because there is no R wave with a high enough amplitude and a large enough slope).

2. Synchronous defibrillator. This defibrillator synchronizes the defibrillation with the patient's own R-wave. Generally, an electronic control circuit is used to control the release of current pulses using the R wave so that the electric shock pulse falls exactly on the descending branch of the R wave. This way, the electric shock pulse will not fall during the irritable period, thereby avoiding ventricular fibrillation. It can be used for all rapid arrhythmias except ventricular fibrillation and flutter, such as supraventricular and ventricular tachycardia, atrial fibrillation and flutter, etc.

According to the position of the electrode plate

1. Internal defibrillator. This type of defibrillator places electrodes inside the chest that come into direct contact with the myocardium to perform defibrillation. Early defibrillation was mainly used for direct myocardial electric shock during open-chest heart surgery. This type of internal defibrillator had a simple structure. Modern internal defibrillators are embedded, which is quite different from early internal defibrillators. In addition to automatic defibrillation, they can also automatically monitor the ECG, determine arrhythmias, and select treatments.

2. External defibrillator. This type of defibrillator places electrodes outside the chest and indirectly contacts the myocardium for defibrillation. Most of the defibrillators currently used clinically belong to this type.

Most common cardiac defibrillators use the RLC damping discharge method, and the basic principle of charging and discharging is shown in the figure on the right.

The voltage converter converts low DC voltage into pulsed high voltage, and charges the energy storage capacitor C after high voltage rectification, so that the capacitor can obtain a certain amount of energy storage. During defibrillation treatment, the high-voltage relay J is controlled to operate, so that the charging circuit is cut off, and the energy storage capacitor C, inductor L and the human body (load) are connected in series to form an RLC (R is the sum of the human body resistance, the wire resistance itself, and the contact resistance between the human body and the electrode) series resonant attenuated oscillation circuit, that is, a damped oscillation discharge circuit, which stimulates the myocardium through the current of the human heart to complete the defibrillation function.

1. Ventricular fibrillation is an absolute indication for electrical cardioversion.

2. Chronic atrial fibrillation (history of atrial fibrillation within 1 to 2 years), continuous atrial flutter.

3. Patients with paroxysmal supraventricular tachycardia who are resistant to conventional treatment and have obvious hemodynamic disorders, or patients with preexcitation syndrome and supraventricular tachycardia who have difficulty taking medication.

4. Atrial flutter with 1:1 conduction.

1. Bradyrrhythmias, including sick sinus syndrome.

2. Arrhythmias caused by excessive dose of digitalis (except ventricular fibrillation).

3. Atrial fibrillation, atrial flutter, and atrial tachycardia with high-degree or complete conduction block.

4. Electrical cardioversion is not recommended for severe hypokalemia.

5. Patients with enlarged left atrium, atrial fibrillation lasting for more than one year, and long-term normal ventricular rate.

Procedure/defibrillator

1. Quickly familiarize yourself with and check the defibrillator, and make sure all buttons, knobs, and electrode pads are in good condition and have sufficient power.

2. The patient lies supine, and the operator is on the patient's right side.

3. Quickly turn on the defibrillator, adjust it to the monitoring position, and display the patient's heart rhythm.

4. Quickly wipe the patient's chest skin with a dry cloth and apply special conductive glue to the manual defibrillator electrode pads.

5. Make sure the manual defibrillator electrode pads are correctly placed on the chest, with the front electrode pad placed above the outer edge of the sternum and below the right clavicle. The outer electrode pad was placed on the left lower chest, left side of the nipple, with the center of the electrode pad on the anterior axillary line, and the ECG wave pattern was observed to determine whether it was ventricular fibrillation.

6. Select the defibrillation energy: 200J for the first defibrillation; 200-300J for the second defibrillation; and 360J for the third defibrillation.

7. Press the defibrillator charging button to charge the defibrillator.

8. Place the defibrillator electrode pads close to the chest wall and apply appropriate pressure to ensure that no one around has direct or indirect contact with the patient.

9. When the defibrillator displays a defibrillation signal, use both hands to coordinately press the two discharge buttons of the manual electrodes to deliver an electric shock.

10. Do not remove the electrodes after the discharge is completed, and observe the heart rhythm after defibrillation. If it is still ventricular fibrillation, choose the second and third defibrillation, and repeat steps 4 to 10.