Aires Ana, Andrade António, Azevedo Elsa, Gomes Filipa, Araújo José Paulo, Castro Pedro
Department of Neurology, Centro Hospitalar Universitário São João, Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
Department of Clinical Neurosciences and Mental Health, Faculty of Medicine of University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.
Brain Sci. 2020 Oct 7;10(10):714. doi: 10.3390/brainsci10100714.
The hemodynamic consequences of a persistent reduced ejection fraction and unknown cardiac output on the brain have not been thoroughly studied. We sought to explore the status of the mechanisms of cerebrovascular regulation in patients with heart failure with reduced (HFrEF) and recovered (HFrecEF) ejection fraction. We monitored cerebral blood flow velocity (CBFV) with transcranial Doppler and blood pressure. Cerebral autoregulation, assessed by transfer function from the spontaneous oscillations of blood pressure to CBFV and neurovascular coupling (NVC) with visual stimulation were compared between groups of HFrEF, HFrecEF and healthy controls. NVC was significantly impaired in HFrEF patients with reduced augmentation of CBFV during stimulation (overshoot systolic CBFV 19.11 ± 6.92 vs. 22.61 ± 7.78 vs. 27.92 ± 6.84, = 0.04), slower upright of CBFV (rate time to overshoot: 1.19 ± 3.0 vs. 3.06 (4.30) vs. 2.90 ± 3.84, = 0.02); = 0.023) and reduced arterial oscillatory properties (natural frequency 0.17 ± 0.06 vs. 0.20 ± 0.09 vs. 0.24 ± 0.07, = 0.03; attenuation 0.34 ±0.24vs 0.48 ± 0.35 vs. 0.50 ± 0.23, = 0.05). Cerebral autoregulation was preserved. The neurovascular unit of subjects with chronically reduced heart pumping capability is severely dysfunctional. Dynamic testing with transcranial Doppler could be useful in these patients, but whether it helps in predicting cognitive impairment must be addressed in future prospective studies.
射血分数持续降低及心输出量不明对大脑血流动力学的影响尚未得到充分研究。我们试图探讨射血分数降低（HFrEF）和射血分数恢复（HFrecEF）的心力衰竭患者脑血管调节机制的状况。我们用经颅多普勒和血压监测脑血流速度（CBFV）。比较了HFrEF组、HFrecEF组和健康对照组之间通过从血压的自发振荡到CBFV的传递函数评估的脑自动调节以及视觉刺激下的神经血管耦合（NVC）。HFrEF患者的NVC明显受损，刺激期间CBFV增加减少（收缩期CBFV峰值：19.11±6.92 vs. 22.61±7.78 vs. 27.92±6.84，P = 0.04），CBFV直立较慢（达到峰值的时间：1.19±3.0 vs. 3.06（4.30）vs. 2.90±3.84，P = 0.02；P = 0.023），动脉振荡特性降低（固有频率0.17±0.06 vs. 0.20±0.09 vs. 0.24±0.07，P = 0.03；衰减0.34±0.24 vs 0.48±0.35 vs. 0.50±0.23，P = 0.05）。脑自动调节功能得以保留。长期心脏泵血能力降低的受试者的神经血管单元严重功能失调。经颅多普勒动态测试对这些患者可能有用，但它是否有助于预测认知障碍必须在未来的前瞻性研究中加以探讨。
