Which of the following is the most likely etiology of unexplained syncope in a young person without
concurrent cardiovascular disease?
. Vasovagal reflex
Which of the following characteristics are typical for spontaneous vasovagal reflex during head-up tilt
test (i.e. obtained without pharmacological provocation):
. Younger patient with lower blood pressure, and more syncopal spells in past history.
Which of the following statements is true in regard to resting neuroendocrine profile among patients
diagnosed with vasovagal reflex using a head-up tilt test?
. Both groups share similar resting neuroendocrine profile.
Which of the cardio- and vasoactive neurohormones increase before and during spontaneous
syncope during head-up tilt test?
. Epinephrine and vasopressin.
5 The vasovagal reflex is traditionally divided into three types of responses: cardioinhibitory (pause >
3 seconds or bradycardia <40/min over a period > 10 seconds), vasodepressor type (without
pronounced heart rate reduction during syncope), and a mixed type (both heart rate reduction and
hypotension are present). Which of the following is true in regard to spontaneous vasovagal reflex
during head-up tilt test (i.e. obtained without pharmacological provocation):
B. Cardioinhibitory type is more common in spontaneous reflex.