upright tilt test

The upright tilt test is an auxiliary test method for checking the normality of a venous blood vessel. In patients with vasovagal syncope, when the supine position becomes inclined, the blood flow of the lower part of the body is more prominent than that of healthy people. The blood volume of the heart is suddenly excessively reduced, the left ventricle is strongly contracted, and the left ventricular area is stimulated. The mechanical receptor C fiber, whereby the receptor produces a strong impulse to the brainstem, the reflex causes the sympathetic nerve activity to decrease, the vagus nerve excites hyperthyroidism, resulting in slow heart rate and peripheral vasodilation, decreased cardiac output, decreased blood pressure, and syncope. Through this examination, the corresponding symptoms can be judged. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Tips: Fasting for 4 hours before the test. Normal value Normal reactions in the tilt test include: 1. The heart rate increases by about 10-15 times/min; 2. The diastolic blood pressure is increased by 10 mmHg, and the systolic blood pressure is basically unchanged. When the normal human body changes from supine position to erect, about 300-800 ral blood is transferred from the thoracic cavity to the lower limb, resulting in an increase in venous volume, a decrease in ventricular preload, a decrease in cardiac output, a decrease in arterial pressure, and aortic arch and cervical sinus baroreceptor tension. Attenuated, the vagal nerve afferent tension disappeared, and the sympathetic nerve signal increased, which was compensated by increased heart rate and peripheral vasoconstriction to increase cardiac output. Therefore, the normal physiological response is a slight increase in heart rate, a slight decrease in systolic blood pressure, an increase in diastolic blood pressure, and an average arterial pressure. Clinical significance Abnormal results: There are several types of abnormal reactions: 1. The steric tachycardia syndrome (POTS) heart rate increased by >30 beats / min or the pulse lasted 120 beats / min, many complained of heart palpitations, fatigue, syncope precursors. 2. The hypotensive hypotensive systolic blood pressure is reduced by at least 20 mmHg or the diastolic blood pressure is reduced by at least 10 mmHg. 3. Vasovagal syncope usually manifests as a sudden drop in blood pressure accompanied by symptoms, mostly occurring more than 10 minutes after the start of the tilt test, often accompanied by bradycardia. The decrease in blood pressure and the slowing of the heart rate may not be completely parallel. The heart rate is slowed down as a prominent manifestation of the heart-suppressed type, and the blood pressure is reduced as a prominent manifestation. The heart rate is mildly slowed down to an angiogenesis type, and the heart rate and blood pressure are significantly decreased. type. 4. Autonomic dysfunction Systolic blood pressure and diastolic blood pressure immediately and continuously decreased without a significant increase in heart rate, leading to loss of consciousness, accompanied by hyperhidrosis, constipation, fear of heat and other manifestations of autonomic dysfunction. 5. Psychological factors respond to symptoms without corresponding changes in heart rate and blood pressure. 6. Cerebral syncope In the tilt test, cerebrovascular ultrasonography suggests cerebrovascular contraction without hypotension or bradycardia. Those who need to be examined for vascular abnormalities are used to evaluate syncope. Precautions Contraindications before the test: fasting for 4 hours before the test, with a defibrillator and rescue drugs. Requirements for examination: If it is the first test, it is necessary to stop the cardiovascular active drug for more than 5 half-lives, and inject normal saline before the test. If the efficacy of the drug is evaluated, the test should be placed at the same time to reduce the error caused by the diurnal variation of the autonomic nerve, and try to keep the drug dosage, duration and other test conditions consistent. During the test, heart rate and blood pressure should be continuously monitored and recorded. Inspection process The subjects were placed on a sloping bed, lying in a quiet state for 10 minutes, connected with blood pressure ECG monitoring, open the venous access, and massaged the left carotid sinus for 5-10 seconds under monitoring (patients over 60 years old did not perform this test). If there is no carotid sinus allergy performance, after routine blood pressure measurement, the bed is tilted to 60-80 degrees for 3-5 seconds, lasting 25-45 minutes, and the blood pressure heart rate is measured every 3-5 minutes. Not suitable for the crowd Inappropriate population: 1. Cardio-cerebral vascular disease: aortic stenosis or left ventricular outflow stenosis caused by syncope; severe mitral stenosis with syncope; known syncope with severe proximal coronary stenosis; severe brain Patients with vasopathic syncope; 2. Pregnancy; 3. Patient rejection.

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