Cardiac resynchronisation therapy

Cardiac resynchronisation is indicated for patients in whom the left and right ventricles no longer contract simultaneously. Through the implantation of a pacemaker or defibrillator with an additional lead to the left ventricle, the right and left halves of the heart can be stimulated simultaneously. Simultaneous stimulations ensures higher muscle strength. This has been demonstrated by echocardiography findings. In the long term, the enlarged heart may even shrink back to its normal dimensions.

People who qualify for resynchronisation therapy are patients with advanced heart failure who, despite optimal pharmacological treatment, have very limited exercise tolerance because of asynchronous contraction of the heart muscle.

The resynchronisation system consists of:

  • a device (a pacemaker or defibrillator with a battery)
  • two or three pacing leads to the heart


You are admitted to the Cardiology Department. You will have to have fasted as the procedure is performed under general anaesthetic. That means at least two hours for clear fluids (only water, tea and coffee), at least six hours for a light meal and dairy products and at least eight hours for a regular meal.

Medication may be taken as agreed with the physician. If no recent laboratory results are available, blood samples may be collected.

You will be given a gown to wear. The nurse will place an IV line in your arm to administer medication later.

The procedure is performed in the cardiac catheterisation room.


You take place on the examination table. Adhesive electrodes are placed to monitor your heart rhythm. Two larger adhesive patches are placed for the conduction of shocks, if necessary. You will be given antibiotics through the IV as protection against infection.

The anaesthetist takes care of the anaesthesia. You will be asleep during the procedure.

An area of skin on the left shoulder measuring 10 by 10 cm is shaved and disinfected, and adhesive sterile sheets are placed around it. A local anaesthetic is injected to numb the skin and the underlying subcutaneous tissue. The physician makes a small incision of 4 mm. A small vein between the muscles is identified that allows for the delivery of one or two electrodes to the heart. For the third pacing lead, the physician pricks a larger vein under the collar bone. Two electrodes are placed in the right heart cavities and the contacts are checked for quality.

A third electrode must stimulate the left chamber of the heart. To reach this, a vein can be used that runs from the right atrium around the heart to the left side. This requires adequate expertise by the physician and may take some time.

Once the pacing leads are secured, a space is created under the skin near the shoulder for the pacemaker or defibrillator. A defibrillator requires additional evaluation of the shock treatment and to that end, a high heart rate is induced. The skin is closed with absorbable sutures and the wound is covered with a plaster. You will wake up in the recovery room. The procedure takes approximately one to two hours.

If all checks of the device are found to be in order the next day, you may go home.


Local bruising is possible but does generally not require much looking after. When opening the deep vein, the lung may be accidentally perforated, resulting in a collapsed lung. Radiography is therefore always performed after the procedure to detect this. In very rare cases, the wound gets infected despite the precautions taken. Sometimes antibiotics must be administered and/or the device must be removed. In the first weeks after the procedure, the electrodes may migrate which will necessitate another intervention. In rare cases, the third pacing lead stimulates not only the heart but also the midriff to contract. You may sense this ‘hiccup’ more in certain positions. This problem usually disappears by reprogramming the device.


Cardiac resynchronisation should ensure smoother breathing, which is beneficial for your exercise tolerance. The risk of future hospitalisation due to ‘fluid in the lungs’ decreases. The number of medications can potentially be reduced, but this may only be done on the advice of your attending physician. A defibrillator also provides optimal protection against the negative effects of the accelerated heart rate. You may still have palpitations or faint, but the device will remedy the rhythm disturbance. Further follow-up is in the outpatients clinic through three to six-monthly consultations. Telemonitoring may also be helpful in the follow-up. Depending on the intensity of use, the pacemaker or defibrillator battery will last up to eight years. The regular follow-up will flag the need for replacement of the device.


To prevent infection the plaster will stay in place for a few days. Do not shower or bathe in the first week. Avoid too much movement of the shoulder girdle. Monitor your weight closely in the first few weeks: resynchronisation will ensure a fair amount of urine production.

Latest publication date: 23/08/2021