Arrhythmia refers to abnormal rhythms of the heart which in turn causes the heart to pump blood less effectively. The common symptoms of cardiac arrhythmia are dizziness, shortness of breath, lightheadedness, rapid heartbeat, heart palpitations, chest pain, blackouts, visual problems, and fainting. Since different patients suffer from these symptoms at different frequencies; they are unlikely to be diagnosed by the conventional Holter monitoring that monitors the heart for 24-48 hours, or an ECG. The above mentioned tests allow the doctor to look at the hearts activity at rest and at one point in time. But abnormal heart rhythms and cardiac symptoms may come and go. So to record your heart rate and rhythm during a symptom there is a device called as the External Loop Recorder (ELR). An ELR has capability to monitor a patients heart for a long duration (7-30 days), and hence has a higher chance of providing a diagnosis to patients with infrequent symptoms.