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Cardiac Resynchronization


Heart failure is a syndrome generally caused by a decrease in the ability of the ventricles to contract. However, in some patients with heart failure, the ventricles not only contract slightly, but also in a disorderly (desynchronized) way. It is easy to imagine that if, in addition to contracting little, they contract out of sync, the performance of cardiac function is further impoverished, making heart failure worse.


Cardiac resynchronization therapy seeks to solve intraventricular and interventricular desynchronization problems by means of pacemakers that stimulate both the right and left ventricles (biventricular pacemakers) so that both contract simultaneously, thus solving the problem. In this way, the biventricular pacemaker improves the symptoms of heart failure.

DAI en las manos.jpg

What is a cardiac resynchronizer?


A cardiac resynchronizer is a pacemaker that has one lead located in the right ventricle and one in the left ventricle. In this way, we can program that both electrodes receive a synchronized impulse, with which we achieve a synchronous movement of both ventricles.


In addition, we can implant an electrode in the right atrium to achieve synchronization of atrial and ventricular movement. This is called a triple chamber pacemaker.


For whom is Cardiac Resynchronization Therapy indicated?


Candidates for this therapy are patients with severe heart failure who also show signs of intraventricular dyssynchrony. These signs can be suspected simply by a simple electrocardiogram, in the presence of intraventricular conduction disorders such as left bundle branch block, and are confirmed by cardiac ultrasound.


What does the intervention consist of?


The procedure for implanting a resynchronizer is very similar to that of a conventional pacemaker , with the exception that an electrode must be accommodated in one of the cardiac veins that surround the left ventricle. This is achieved by means of guides and catheters after puncturing a vein that runs close to the clavicular region.

Tomar el pulso de un paciente de edad av

What does the intervention consist of?

Depending on the preferences of the patient and the surgeon, the ICD is implanted close to the deltopectoral groove, close to the clavicle and the right or left pectoral muscle.

The surgeon will locate a vein through which to insert the electrode (s) to be implanted. Using X-rays, he will place the tip of the electrode in close contact with the heart muscle at the tip of the right ventricle or with the outflow tract of the right ventricle. If a second electrode is required, the tip of the latter will be in close contact with the wall of the right atrium. Subsequently, with a specific device, it will measure whether the electrodes are in the correct location and perform an electrophysiological study to verify the correct functioning of the ICD. If so, it will connect the proximal end of the electrodes to the generator, which will be housed in an infrapectoral bag made for this purpose.

Your DAI will be ready to go. In the event of an event (need for overstimulation, shock ...) it is recorded with the date and time of the event.

Before the intervention

Except in urgent cases, the intervention will be carried out on a date suitable for you and with the availability of an operating room by the surgeon. You should inform him of your recent health status including if you have had a cold, tooth decay, or fever. Remember to bring the medications you are taking or have taken in recent days to the Hospital. You will probably enter the day before or the morning of the intervention.

The area near the surgical field will be shaved. With this we avoid future infections. After admission, an electrocardiogram, a blood test and a chest X-ray will be performed (if not already done).

As part of your pre-anesthetic medication, you will likely be given a sedative to help you relax before going to the operating room. Once in the operating room, a route will be taken to administer an antibiotic to prevent infections.

During the intervention

The intervention is carried out in the operating room with local, local plus sedation or general anesthesia.

The operation can last between half and 2 hours on average.

After the intervention

Generally it only needs to be cured with a local antiseptic until the wound is completely healed. The next day you will be discharged after checking the correct functioning of the pacemaker.

You should not do rough exercises with your arm on that side for 1 month.

You should not drive for at least 3 months.

If you have ventricular tachycardia, you will probably notice palpitations from overstimulation. If you have ventricular fibrillation, your chest may jerk or pass out during fibrillation and feel nothing. Contact your doctor in the event of two or more electrical shocks within 24 hours.

Cirujanos durante la operación
Esquema DAI.jpg

How often should the ICD be checked?

You must go to periodic annual controls to review the operation of the DAI. ICDs are checked with a device called a "programmer." When the programmer is placed on top of the DAI, information on its operation can be obtained. The programmer can also be used to change DAI controls.

The ICD battery typically lasts 4 to 8 years. When the battery runs out, a new pacemaker must be implanted. The procedure to remove the old ICD and place a new one typically requires local anesthesia. In most cases it is not necessary to change the original electrodes.

Doctor con archivos

Do electronic devices affect the operation of the ICD?

The devices below do not affect or damage ICDs. Most of the people can have contact with these devices without needing to worry.

  • Civil band radios

  • Electric Drills

  • Electric blankets

  • Electric shavers

  • Amateur radios

  • Electric pads

  • Metal detectors

  • Microwaves

  • Television transmitters

  • TV remote controls

  • X-ray machines

  • Airport security equipment

The devices below do affect ICDs. Pacemakers may not function properly when in contact with these devices.

  • Generator sets

  • Welding equipment

  • Some appliances used by dentists

  • MRI machines

  • Radiation therapy machines for cancer treatment

  • Heavy equipment or motors with strong magnets

Can I use cell phones if I have an ICD implanted?

It is convenient to carry the mobile phone more than 15 cm away from the ICD. In addition, you should speak with the hand opposite to the place where the ICD is implanted. Although interference with current mobile phones has not been demonstrated, increasing the number of frequencies in use could change this.

Hombre sonriente con un teléfono intelig
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