Cardioverter-defibrillator

The implantation of a cardioverter-defibrillator (ICD) is a medical procedure that allows to control cardiac arrhythmias (the formation and conductivity of electrical impulses). These abnormalities cannot be managed through pharmacological treatment, or can be treated this way to a very limited degree. The implantation of a cardioverter-defibrillator is a treatment subjected to choice.

In the case of severe heart conditions, the implantation of the cardioverter-defibrillator (ICD) is essential before performing the procedure of ablation (i.e. the obliteration) of these parts of the heart that are responsible for the formation of life-threatening and health-threatening arrhythmias.

The implantation of the cardioverter-defibrillator is performed in the operating room. The patient should present a set of basic medical test results, i.e. the ECG, the complete blood count, the blood type, the level of electrolytes, urea, and creatinine in blood, TSH, the coagulation parameters (the INR, the prothrombin time, the activated partial thromboplastin time (APTT), and fibrinogen), and the blood type.

The patient has to be on an empty stomach before the procedure.

The procedure is carried out under a local anaesthetic in the subclavian area. After anesthetizing the patient, an incision is performed in the subclavian area, the tissues are dissected in order to expose the cephalic vein or a puncture of the subclavian vein is performed (the area of the shoulder and clavicle). The access to these vessels may cause unpleasant sensations; however, the patient, who is fully conscious during the procedure, can report these discomforts to the surgeon, which will allow to remove them. Then, an electrode or electrodes are introduced to the heart through the vessels mentioned above, and the cardioverter-defibrillator is placed in the bed between the subcutaneous tissue and the muscles below the clavicle.

Then the patient is put into a deep sleep (under general anaesthesia) in order to check how the device works after inducing ventricular fibrillation.

After the procedure, the patient has to be immobilised in bed for a period of time in order to prevent the displacement of the implanted electrode or electrodes.

Possible complications related to the implantation of the cardioverter-defibrillator:

• Complications related to the implantation of the electrode: the perforation of the heart chambers, an infection, a pneumothorax, a damage/fracture to the electrode, displacement of the electrode, venous embolism and thrombosis.Complications related to the implantation of the cardioverter-defibrillator:

a hematoma of the bed, an infection, displacement of the cardioverter-defibrillator, pain and damage to the skin.

• Possible malfunction of the cardioverter-defibrillator that may lead to death, myocardial infarction, embolism and thrombosis, angina pectoris, and circulatory failure.
• Inadequate therapy, which may lead to serious arrhythmias such as ventricular fibrillation and/ or ventricular tachycardia.
• Inadequate therapy of ventricular tachycardia, which may lead to ventricular fibrillation and atrial fibrillation.
• There is a possibility of extending the stay in hospital, a surgical intervention, replacing the implanted device, increase in the stimulation/ defibrillation threshold, sensing disorders, increase in the stimulation level, ineffective stimulation and the stimulation of the thoracic diaphragm.