External Counterpulsation Reduces Beat-to-Beat Blood Pressure Variability When Augmenting Blood Pressure and Cerebral Blood Flow in Ischemic Stroke

Abstract

Background and PurposeExternal counterpulsation (ECP) is a noninvasive method used to enhance cerebral perfusion by elevating the blood pressure in ischemic stroke. However, the response of the beat-to-beat blood pressure variability (BPV) in ischemic stroke patients during ECP remains unknown.MethodsWe enrolled recent ischemic stroke patients and healthy controls. Changes in the blood flow velocities in bilateral middle cerebral arteries and the continuous beat-to-beat blood pressure before, during, and after ECP were monitored. Power spectral analysis revealed that the BPV included oscillations at very low frequency (VLF; <0.04 Hz), low frequency (LF; 0.04–0.15 Hz), and high frequency (HF; 0.15–0.40 Hz), and the total power spectral density (TP; <0.40 Hz) and LF/HF ratio were calculated.ResultsWe found that ECP significantly increased the systolic and diastolic blood pressures in both stroke patients and controls. ECP decreased markedly the systolic and diastolic BPVs at VLF and LF and the TP, and the diastolic BPV at HF when compared with baseline. The decreases in diastolic and systolic BPV reached 37.56% and 23.20%, respectively, at VLF, 21.15% and 12.19% at LF, 8.76% and 16.59% at HF, and 31.92% and 23.62% for the total TP in stroke patients, which did not differ from those in healthy controls. The change in flow velocity on the contralateral side was positively correlated with the total TP systolic BPV change induced by ECP (r=0.312, p=0.035).ConclusionsECP reduces the beat-to-beat BPV when increasing the blood pressure and cerebral blood flow velocity in ischemic stroke patients. ECP might be able to improve the clinical outcome by decreasing the beat-to-beat BPV in stroke patients, and this should be explored further in future studies.

Expert consensus on the clinical application of enhanced external counterpulsation in elderly people (2019)

“…32,33 Therefore, currently, for patients with ischemic stroke, a total of >10 hours of EECP treatment with pressure at 150 mmHg is recommended. In addition, these authors found that EECP significantly reduces variability in blood pressure and heart rate, 34,35 which indicated that EECP improved autonomic dysfunction in patients with ischemic stroke. There were few studies of EECP on the posterior circulation.…”

Prefrontal hemodynamic changes measured using near-infrared spectroscopy during the Valsalva maneuver in patients with orthostatic intolerance

“…1,23 (3) Alternative adrenergic barosensitivity (BRSa 1 ) was defined as the sum of the SBP decrement during early phase II and two-thirds of the SBP decrement in phase III divided by PRT. 24,25 (4) BRSv was determined as the regression slope of the R − R interval (milliseconds) over SBP during early phase II. [24][25][26][27] Using the cutoff value for each parameter, patients with an abnormal result in any of the four parameters were placed into the AbVM group.…”

“…Overall hemodynamic autoregulation during VM is a key factor in preventing the development of significant clinical symptoms such as orthostatic intolerance (OI), which is one of the representative manifestations of autonomic dysfunction or syncope. 3,4 However, BP and HR monitoring alone is not enough to detect pathologic dysfunction of the ANS. In addition, the mechanisms behind VM that determine the symptoms caused by autonomic dysfunction are still unclear.…”

<p>Enhanced External Counterpulsation Efficacy on Exercise Endurance in COPD Patients and Healthy Subjects: A Pilot Randomized Clinical Trial</p>

“…Furthermore, the increase of diastolic blood pressure in the process of exercise cardiopulmonary test after EECP treatment was lower than before treatment, and this is probably due to the effect of external counterpulsation in regulating blood pressure and heart rate. 23,24 These changes may be related to the improvement of cardiovascular fitness and cardiac function with EECP therapy. EECP therapy can improve cardiac function and oxygen uptake; 25 moreover, cardiac function is significantly correlated with exercise capacity.…”