Is vasovagal syncope considered a heart disease?

　　Vasovagal syncope generally refers to vasovagal syncope, which is not a type of heart disease but may cause symptoms resembling cardiac discomfort. The detailed analysis is as follows:

　　Vasovagal syncope is a condition triggered by various stimuli—such as excessive mental stress, emotional tension, pain, or extreme fatigue—that activate a vagus nerve-mediated reflex. This leads to widespread blood vessel dilation, reduced venous return to the heart, resulting in bradycardia (slowed heart rate), hypotension (low blood pressure), cerebral hypoxia (insufficient oxygen to the brain), and ultimately syncope. In contrast, heart diseases are primarily caused by congenital or acquired structural or functional abnormalities in the myocardium, blood vessels, heart valves, or cardiac conduction system. Therefore, vasovagal syncope does not fall under the category of heart disease.

　　After an episode of vasovagal syncope, physical examination, electrocardiogram (ECG), and other tests can be used to differentiate it from heart disease.