Department of Radiology, Landspitali-The National University Hospital of Iceland, Hringbraut, 101 Reykjavik, Iceland.
Icelandic Heart Association, Holtasmari 1, 201 Kopavogur, Iceland.
Europace. 2018 Aug 1;20(8):1252-1258. doi: 10.1093/europace/eux220.
Atrial fibrillation (AF) has been associated with cognitive impairment. Additionally, brain volume may be reduced in individuals with AF. Potential causes may include cerebral micro-embolism or reduced stroke volume due to the beat-to-beat variation in AF. The aims of this study were to measure cerebral blood flow and estimate whole brain perfusion in elderly individuals with and without AF.
Blood flow in the cervical arteries was measured with phase contrast MRI and brain perfusion estimated in a large cohort from the AGES-Reykjavik Study. Individuals were divided into three groups at the time of the MRI: persistent AF, paroxysmal AF, and no history of AF. Of 2291 participants (mean age 79.5 years), 117 had persistent AF and 78 had paroxysmal AF but were in sinus rhythm at the time of imaging AF. Those with persistent AF had lower cholesterol and used more anti-hypertensive medication and warfarin. The three groups were similar with regard to other cardiovascular risk factors. Those in the persistent AF group had significantly lower total cerebral blood flow on average, 472.1 mL/min, both when compared with the paroxysmal AF group, 512.3 mL/min (P < 0.05) and the no AF group, 541.0 mL/min (P < 0.001). Brain perfusion was lowest in the persistent AF group, 46.4 mL/100 g/min compared with the paroxysmal AF group, 50.9 mL/100 g/min in (P < 0.05) and those with no AF, 52.8 mL/100 g/min (P < 0.001).
Persistent AF decreases blood flow to the brain as well as perfusion of brain tissue compared with sinus rhythm.
心房颤动（AF）与认知障碍有关。此外，AF 患者的脑容量可能会减少。潜在的原因可能包括由于 AF 的每搏变化导致的脑微栓塞或每搏输出量减少。本研究的目的是测量老年人伴有和不伴有 AF 的大脑血液流量并估计全脑灌注。
通过相位对比 MRI 测量颈内动脉的血流，并在来自 AGES-Reykjavik 研究的大型队列中估计脑灌注。在 MRI 时，将个体分为三组：持续性 AF、阵发性 AF 和无 AF 史。在 2291 名参与者（平均年龄 79.5 岁）中，117 名患有持续性 AF，78 名患有阵发性 AF，但在成像时处于窦性心律。持续性 AF 患者的胆固醇水平较低，并且使用更多的抗高血压药物和华法林。三组在其他心血管危险因素方面相似。持续性 AF 组的总脑血流量平均显着降低，为 472.1mL/min，与阵发性 AF 组（512.3mL/min，P<0.05）和无 AF 组（541.0mL/min，P<0.001）相比。持续性 AF 组的脑灌注最低，为 46.4mL/100g/min，与阵发性 AF 组（50.9mL/100g/min，P<0.05）和无 AF 组（52.8mL/100g/min，P<0.001）相比。
与窦性心律相比，持续性 AF 会降低大脑的血流量和脑组织的灌注。
