Patients may have unexplained recurrent symptoms of dizziness, palpitation or loss of consciousness. There are many causes, such as arrhythmias (abnormal heart rhythm). Sometimes, a definitive diagnosis cannot be made after conventional investigations.
Implantable loop recorder (ILR) is used to check whether the symptoms are due to arrhythmias. It is a small device implanted usually under the skin of the left chest wall. It consists of 2 internal electrodes, through which the heart rhythm can be monitored. The battery can last for >12 months.