Upright tilt test

The upright tilt test is an auxiliary examination method used to check whether the veins are normal. In patients with vasovagal syncope, when the supine position changes to the inclined position, the degree of blood flow stasis in the veins of the lower part of the body is more significant than that of healthy people. The amount of blood returned to the heart suddenly decreases, the left ventricle contracts strongly, and the lower left ventricle is stimulated. The mechanoreceptor C fiber, which has a strong impulse, is transmitted to the brain stem. The reflex causes a decrease in sympathetic nerve activity and hyperstimulation of the vagus nerve, which leads to slow heart rate and peripheral vasodilation, decreased cardiac output, decreased blood pressure, and syncope. Through this examination, the corresponding symptoms can be judged.