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Updated: Aug 20, 2026

Assessing Cerebral Autoregulation via Oscillatory Lower Body Negative Pressure and Projection Pursuit Regression
Published on: December 10, 2014
Enhanced external counterpulsation does not compromise cerebral autoregulation
H Marthol1, D Werner, C M Brown
1Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany.
Objectives:
Enhanced external counterpulsation (EECP) rhythmically augments blood pressure (BP) by diastolic lower-body compression. Recently, we showed decreased mean cerebral blood flow velocity (CBFVmean) in young healthy persons during EECP, but unchanged CBFVmean in atherosclerotic patients. In this study, we assessed EECP effects on dynamic cerebral autoregulation (CA).
Material & Methods:
In 23 healthy persons and 15 atherosclerotic patients we monitored heart rate (HR), mean BP (BPmean) and CBFVmean before and during 5 min EECP. We analyzed spectral powers of HR, BPmean and CBFVmean in the low (LF: 0.04-0.15 Hz) and high (HF: 0.15-0.5 Hz) frequency ranges to determine CA from the LF-transfer function gain and phase shift between BPmean and CBFVmean oscillations.
Results:
EECP increased HR and BPmean, while transfer function gain and phase shift remained stable.
Conclusions:
Stable gain and phase values suggest that EECP does not compromise CA and, therefore, does not seem to bear cerebrovascular risks.
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Measurement of Blood Pressure
Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
Equipments Used To Measure Blood Pressure
This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive...

