title: Increasing pressure of external counterpulsation augments blood pressure but not cerebral blood flow velocity in ischemic stroke.
abstract: External counterpulsation (ECP) is a noninvasive method used to augment cerebral perfusion but the optimal use of ECP in ischemic stroke has not been well documented. We aimed to investigate the effects of ECP treatment pressure on cerebral blood flow and blood pressure (BP). We recruited 38 ischemic stroke patients with large artery occlusive disease and 20 elderly controls. We commenced ECP treatment pressure at 150 mmHg and gradually increased to 187.5, 225 and 262.5 mmHg. Mean cerebral blood flow velocities (CBFV) of bilateral middle cerebral arteries and continuous beat-to-beat BP were recorded before ECP and during each pressure increment for 3 minutes. Patient CBFV data was analyzed based on whether it was ipsilateral or contralateral to the infarct. Mean BP significantly increased from baseline in both stroke and control groups after ECP commenced. BP increased in both groups following raised ECP pressure and reached maximum at 262.5 mmHg (patients 16.9% increase versus controls 16.52%). The ipsilateral CBFV of patients increased 5.15%, 4.35%, 4.55% and 3.52% from baseline under the four pressures, respectively. All were significantly higher than baseline but did not differ among different ECP pressures; contralateral CBFV changed likewise. Control CBFV did not increase under variable pressures of ECP. ECP did increase CBFV of our patients to a roughly equal degree regardless of ECP pressure. Among the four ECP pressures tested, we recommend 150 mmHg as the optimal treatment pressure for ischemic stroke due to higher risks of hypertension-related complications with higher pressures.
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region.
authors: Wenhua
authors: W
authors: Lin
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region.
authors: Li
authors: L
authors: Xiong
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region.
authors: Jinghao
authors: J
authors: Han
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region.
authors: Howan
authors: H
authors: Leung
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region.
authors: Thomas
authors: T
authors: Leung
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region.
authors: Yannie
authors: Y
authors: Soo
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region.
authors: Xiangyan
authors: X
authors: Chen
authors: Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Sha Tin, Hong Kong Special Administrative Region. Electronic address: ks-wong@cuhk.edu.hk.
authors: Ka Sing Lawrence
authors: KS
authors: Wong
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D002545:Brain Ischemia / Q000150:complications* / Q000000981:diagnostic imaging / Q000532:radiotherapy; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015908:Counterpulsation / Q000379:methods; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000503:physiopathology; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology*; D015898:Tomography Scanners, X-Ray Computed; D017585:Ultrasonography, Doppler, Transcranial
keywords: Blood pressure; Cerebral blood flow; Cuff pressure; External counterpulsation; Hemodynamics; Ischemic stroke; Transcranial Doppler