In the physiological state, blood vessels can be closed, reduction of blood pressure and blood supply needs to adjust, this contraction is necessary.
In some blood vessels, such as coronary heart with stenosis (thrombus) that, if the recurrence of vasospasm, and so on, can lead to myocardial ischemia, and even sudden death and other critical incidents.
In some blood vessels, such as coronary heart with stenosis (thrombus) that, if the recurrence of vasospasm, and so on, can lead to myocardial ischemia, and even sudden death and other critical incidents.
