Cerebral Blood Flow, Heart Rate, and Blood Pressure Patterns during the Tilt Test in Common Orthostatic Syndromes

Figure 3

Comparisons of three main types of neurally mediated syncope. Syncope is associated with profound decline in BP and in diastolic CBFv. HR and BP responses differentiate each type of syncope while CBFv responses are similar among all syncope types. HR declines before BP in cardiovagal syncope. HR decline is absent in the vasodepressor syncope. HR and BP decline simultaneously in mixed syncope. CBFv shows typical vasodilation pattern in all types of syncope that is characterized by a decline in diastolic and increase in systolic CBFv. The diastolic CBFv is equal or close to zero during syncope.