What diseases can a dynamic electrocardiogram (Holter monitoring) detect?

　　In general, ambulatory electrocardiography (Holter monitoring) may detect conditions such as atrial premature beats, sinus bradycardia, atrial fibrillation, paroxysmal supraventricular tachycardia, and myocardial ischemia. If experiencing any discomfort, timely medical consultation is recommended. Detailed explanations are as follows:

　　1. Atrial Premature Beats

　　Atrial premature beats may be caused by various factors including heart disease, medication effects, electrolyte disturbances, and psychological factors. Ambulatory electrocardiography can record premature atrial P waves, which differ in morphology from sinus P waves. These are often not followed by a QRS complex or are followed by an abnormal QRS morphology. These characteristic changes aid in the diagnosis of atrial premature beats.

　　2. Sinus Bradycardia

　　Sinus bradycardia may be caused by increased vagal tone, sinoatrial node dysfunction, medication effects, or systemic diseases. Ambulatory electrocardiography can record sinus P waves with a frequency below 60 beats per minute, with normal P wave morphology and no prolongation of the PR interval.

　　3. Atrial Fibrillation

　　Atrial fibrillation may be triggered by various factors such as organic heart disease, hyperthyroidism, alcohol consumption, and electrolyte disturbances. Ambulatory electrocardiography can record the disappearance of P waves, replaced by small, irregular baseline fluctuations known as f waves, with an extremely irregular ventricular rate.

　　4. Paroxysmal Supraventricular Tachycardia

　　Paroxysmal supraventricular tachycardia may be caused by abnormalities in the cardiac conduction system, heart disease, or electrolyte disturbances. Ambulatory electrocardiography can record sudden episodes of tachycardia, with a ventricular rate typically between 150 and 250 beats per minute, normal QRS morphology, and regular RR intervals.

　　5. Myocardial Ischemia

　　Myocardial ischemia may be caused by factors such as coronary atherosclerosis, coronary artery spasm, and myocardial bridging. Ambulatory electrocardiography can record electrocardiographic changes associated with myocardial ischemia, such as ST-segment depression and T-wave inversion, which are particularly evident during episodes of ischemia.

　　In daily life, it is advisable to maintain a light diet, reduce intake of salt, fat, and cholesterol, and increase consumption of vegetables, fruits, and fiber-rich foods to help maintain heart health.