A tiny implantable heart monitor for diagnosing sporadic faintings or palpitations
An implantable loop recorder can help establish whether symptoms such as dizziness, blackouts and palpitations have a cardiac cause. It can be difficult to determine if these symptoms are due to heart rhythm problems if they occur only infrequently. Unlike conventional ECG monitoring (such as 24-hour ECG monitor or event monitors), the loop recorder monitors heart rhythm continuously for up to three years so that the likelihood of capturing ECG during symptoms is greatly increased. ILR works much like a black box in an aeroplane, whereby vital information is recorded during the actual episode and can be played back later for detailed analysis.
Syncope may have many different reasons, and arrhythmic causes (abnormal heart rhythm) are the most serious, with the risk of cardiac arrest and death; therefore, reliable diagnosis is of paramount importance. When heart rhythm is recorded during an actual episode, an analysis will show either normal ECG, which means that the cause is not related to arrhythmia, or the ECG is abnormal, confirming arrhythmic cause. In either case, the diagnosis will have been achieved, and the device can be removed. If an abnormal heart rhythm causes the episodes, treatment options include medication, pacemaker, implantable cardioverter-defibrillator (ICD) or catheter ablation. After these treatments, patients can often resume normal activities without fear of suffering another episode.
The procedure is safe, and the risk of complications (approx. 1%) is offset by the benefit of having a correct diagnosis and subsequent appropriate treatment. Complications include wound infection, wound haematoma (blood collection under the skin) and device migration.
You will need a blood test about a week before the procedure. Anticoagulants, i.e. blood-thinning drugs (warfarin, apixaban, edoxaban, rivaroxaban, dabigatran) and clopidogrel, will need to be stopped before the procedure. You can drink water, clear tea and black coffee (without milk) up to 2 hours before the procedure. Milk, food, sweets, tea or coffee with milk can be consumed up to 6 hours before the procedure. Chewing gum and smoking is not permitted on the day of surgery. Please take all your regular medication (except diabetic medication and insulin) as usual with a sip of water. Please bring the actual list of medication, including dosage with you. Dr Ruzicka will explain the procedure to you, and any questions you may have can be answered at this time before you sign the consent form for the procedure. A small cannula will be inserted into your arm. Your heart rhythm and oxygen saturation (oxygen level in the blood) will be monitored throughout the procedure. Shaving at the implant site may be required.
Implanting the loop recorder takes about 20 minutes and is done under a local anaesthetic and sometimes with a small dose of sedation to help you relax. A small injection will be given to numb the skin, and a short incision about 2 cm on the left side of the chest will be made. A space under the skin will be created to accommodate the loop recorder, which is about the size of a memory stick. The wound will be closed with absorbable suture, and the skin will be closed with special glue. The wound will be covered with a dressing.
After the procedure, you will be able to eat or drink and allowed to leave the hospital after approx. 60 minutes of recovery. You won’t be able to drive and will need to arrange your transport. You can return the following day to your normal work or activity. Fitness to drive will depend on your symptoms and will be discussed with Dr Ruzicka. The wound should be kept dry and covered with a dressing for 7 days; afterwards, the dressing can be removed, and you can take a shower or bath. You will receive a follow-up appointment with one of the physiologists at the Alexandra Hospital.