Hermosillo Antonio G, Jordan José Luis, Vallejo Maite, Kostine Andrei, Márquez Manlio F, Cárdenas Manuel
Department of Electrocardiology, Instituto Nacional de Cardiología Ignacio Chávez, Juan Badiano #1, Sección XVI Tlalpan CP 14080, México DF.
Europace. 2006 Mar;8(3):199-203. doi: 10.1093/europace/eul001. Epub 2006 Feb 10.
This study analyses the changes in cerebral blood flow (CBF) velocity occurring in the near syncopal phase of head-up tilt test (HUT) to determine whether their appearance during the premonitory symptoms permits the differentiation of the different types of haemodynamic response.
Six hundred and nineteen patients aged 35.9 +/- 16.4 with a prior history of syncope (55%) or presyncope (45%) were studied. Head-up tilt test was positive in 585 patients. The test was interrupted before syncope, once hypotension was evident and CBF changed. A vasovagal reaction (VVR) was observed in 245 patients. They had a 59% fall in diastolic CBF velocity, whereas systolic CBF velocity decreased by 12%. Postural orthostatic tachycardia syndrome (POTS) was observed in 82, systolic and diastolic CBF velocity decreased 44 and 60%, respectively. A similar response was observed in 258 patients with the orthostatic intolerance (OI) pattern. No significant changes were observed in the negative group.
Patients with VVR had changes in CBF velocity, which are different from those presented by patients with POTS and OI pattern. Cerebral blood flow monitoring is useful to increase the yield of HUT and may allow early interruption before syncope occurs, reducing patient discomfort.
本研究分析头高位倾斜试验（HUT）接近晕厥阶段脑血流（CBF）速度的变化，以确定在前驱症状出现时这些变化是否有助于区分不同类型的血流动力学反应。
对619例年龄为35.9±16.4岁、有晕厥史（55%）或晕厥前症状史（45%）的患者进行了研究。585例患者头高位倾斜试验呈阳性。一旦出现明显低血压且CBF发生变化，就在晕厥前中断试验。观察到245例患者出现血管迷走反应（VVR）。他们的舒张期CBF速度下降了59%，而收缩期CBF速度下降了12%。观察到82例患者出现体位性直立性心动过速综合征（POTS），收缩期和舒张期CBF速度分别下降44%和60%。在258例具有直立不耐受（OI）模式 的患者中观察到类似反应。阴性组未观察到显著变化。
VVR患者的CBF速度变化与POTS和OI模式患者不同。脑血流监测有助于提高HUT的诊断率，并可能在晕厥发生前提前中断试验，减轻患者不适。
