Effect of Serial Remote Ischemic Conditioning on Dynamic Cerebral Autoregulation in Patients With Intravenous Thrombolysis (SRICDCA-IVT)

Inclusion Criteria: * 1\) Age≥18 years, regardless of sex; * 2\) Patients with clinically definite diagnosis of acute ischemic stroke and undergo intravenous thrombolysis with alteplase in 4.5 hours; * 3\) Baseline mRs 2-5; and Premorbid mRS ≤ 1； * 4\) Baseline NIHSS\>= 4, and \<= 24; * 5\) Signed and dated informed consent is obtained; Exclusion Criteria: * 1\) Patients who have the contraindication of intravenous thrombolysis with alteplase; * 2\) Patients with consciousness disorder or restlessness who cannot cooperate with dynamic cerebral autoregulation; * 3\) Patients whose stable cerebral blood flow velocity envelope cannot be obtained by transcranial Doppler ultrasound or whose cerevral blood vessels have not been detected; * 4\) The patients who have the contraindication of remote ischemic conditioning treatment, such as severe soft tissue injury, fracture or vascular injury in the upper limb. Acute or subacute venous thrombosis, arterial occlusive disease, subclavian steal syndrome, etc; * 5\) Pregnant or lactating women; * 6\) Previous remote ischemic conditioning therapy or similar treatment; * 7\) Laboratory indicators are not qualified: Alanine transaminase (ALT) or glutamic-oxalacetic transaminase (AST) continued to rise more than 3 times the upper limit of normal, Serum creatinine \> 265 umol/l (\> 3.0 mg/dl); * 8\) Previous history of atrial fibrillation or ECG showing atrial fibrillation or arrhythmia; * 9\) Patients with a life expectancy of less than 3 months or patients unable to complete the study for other reasons; * 10\) Unwilling to be followed up or treated for poor compliance; * 11\) He/She is participating in other clinical research or has participated in other clinical research or has participated in this study within 3 months prior to admission; * 12\) Other conditions that the researchers think are not suitable for the group.