An abnormal ECG does not necessarily belong to heart disease, but can be altered abnormally by other factors. The most common factor is ionic disorders, for example, when suffering from hypokalemia, hypocalcemia, hypercalcemia, hyponatremia, and hyponatremia, typical ECG-specific changes can occur, and supplementation of ions or correction of ionic disorders can lead to changes in ECG abnormalities. For patients with substantial heart disease, abnormal ECG changes will exist, but patients with cardiac neurosis, such as those with nonfunctional changes in the heart, will also have varying degrees of ECG abnormalities, so ECG abnormalities do not always belong to heart disease.