In 1949, Norman Holter, a biophysicist, created a method to monitor cardiac rhythm in those who were at home or other places. This was a wireless system to monitor clinical signs and symptoms as well as disturbances of the heart rhythm. The advantage of this procedure included observation for longer periods of time than with a traditional electrocardiogram. It explored diagnosis, prognosis, and arrhythmia assessment as well [1, 2, 3, 5].
Moreover, it has become possible to collect information about cardiac activity when patients are asleep, having sex, walking, or other activities. Of especial interest is the observation of malignant heart rhythms such as ventricular tachycardia. Others include atrial fibrillation, premature atrial contractions, and atrioventricular heart block. Obviously, the procedure is beneficial in patients who are at risk for sudden cardiac death [1, 2, 3, 4, 5].