Critical closing pressure monitoring using diffuse correlation spectroscopy in cardiac ablation patients

Author(s):  
Alec Lafontant ◽  
Karla M. Bergonzi ◽  
Rodrigo Forti ◽  
Ronak Shah ◽  
Lin Wang ◽  
...  
2017 ◽  
Vol 37 (8) ◽  
pp. 2691-2705 ◽  
Author(s):  
Wesley B Baker ◽  
Ashwin B Parthasarathy ◽  
Kimberly P Gannon ◽  
Venkaiah C Kavuri ◽  
David R Busch ◽  
...  

The critical closing pressure ( CrCP) of the cerebral circulation depends on both tissue intracranial pressure and vasomotor tone. CrCP defines the arterial blood pressure ( ABP) at which cerebral blood flow approaches zero, and their difference ( ABP −  CrCP) is an accurate estimate of cerebral perfusion pressure. Here we demonstrate a novel non-invasive technique for continuous monitoring of CrCP at the bedside. The methodology combines optical diffuse correlation spectroscopy (DCS) measurements of pulsatile cerebral blood flow in arterioles with concurrent ABP data during the cardiac cycle. Together, the two waveforms permit calculation of CrCP via the two-compartment Windkessel model for flow in the cerebral arterioles. Measurements of CrCP by optics (DCS) and transcranial Doppler ultrasound (TCD) were carried out in 18 healthy adults; they demonstrated good agreement (R = 0.66, slope = 1.14 ± 0.23) with means of 11.1 ± 5.0 and 13.0 ± 7.5 mmHg, respectively. Additionally, a potentially useful and rarely measured arteriole compliance parameter was derived from the phase difference between ABP and DCS arteriole blood flow waveforms. The measurements provide evidence that DCS signals originate predominantly from arteriole blood flow and are well suited for long-term continuous monitoring of CrCP and assessment of arteriole compliance in the clinic.


1976 ◽  
Vol 40 (3) ◽  
pp. 425-433 ◽  
Author(s):  
M. G. Bottomley ◽  
G. W. Mainwood

A device was designed to provide a “square” pulse of blood flow into the arterial system. Pulses were injected into the carotid artery of the rabbit during transient cardiac arrest. Analysis of pressure response curves generated by the flow provides information as to the state of the arterial tree. With certain assumptions it is possible to estimate from these curves lumped values of peripheral resistance, critical closing pressure, and arterial compliance. In a series of 12 rabbits the mean value of peripheral resistance was found to be 0.21 +/- 0.7 mmHg-ml-1-min and critical closing pressure was estimated to be 23.6 +/- 3.8 mmHg. This method gives two possible values for arterial compliance 0.036 +/- 0.010 and 0.055 +/- 0.010 ml-mm-1 based, respectively, on the rise and decay curves of the pressure response. The theory and limitations of the method are discussed. The use of the method is illustrated in following the response to increased PCO2 and hemorrhage.


2009 ◽  
Author(s):  
Louis Gagnon ◽  
Michèle Desjardins ◽  
Louis Bherer ◽  
Frédéric Lesage

2018 ◽  
Vol 40 (1) ◽  
pp. 187-203 ◽  
Author(s):  
Tiffany S Ko ◽  
Constantine D Mavroudis ◽  
Wesley B Baker ◽  
Vincent C Morano ◽  
Kobina Mensah-Brown ◽  
...  

Management of deep hypothermic (DH) cardiopulmonary bypass (CPB), a critical neuroprotective strategy, currently relies on non-invasive temperature to guide cerebral metabolic suppression during complex cardiac surgery in neonates. Considerable inter-subject variability in temperature response and residual metabolism may contribute to the persisting risk for postoperative neurological injury. To characterize and mitigate this variability, we assess the sufficiency of conventional nasopharyngeal temperature (NPT) guidance, and in the process, validate combined non-invasive frequency-domain diffuse optical spectroscopy (FD-DOS) and diffuse correlation spectroscopy (DCS) for direct measurement of cerebral metabolic rate of oxygen ( CMRO2). During CPB, n = 8 neonatal swine underwent cooling from normothermia to 18℃, sustained DH perfusion for 40 min, and then rewarming to simulate cardiac surgery. Continuous non-invasive and invasive measurements of intracranial temperature (ICT) and CMRO2 were acquired. Significant hysteresis ( p < 0.001) between cooling and rewarming periods in the NPT versus ICT and NPT versus CMRO2 relationships were found. Resolution of this hysteresis in the ICT versus CMRO2 relationship identified a crucial insufficiency of conventional NPT guidance. Non-invasive CMRO2 temperature coefficients with respect to NPT ( Q10 = 2.0) and ICT ( Q10 = 2.5) are consistent with previous reports and provide further validation of FD-DOS/DCS CMRO2 monitoring during DH CPB to optimize management.


Author(s):  
Katarzyna Kaczmarska ◽  
Magdalena Kasprowicz ◽  
Antoni Grzanka ◽  
Wojciech Zabołotny ◽  
Peter Smielewski ◽  
...  

2008 ◽  
Vol 16 (20) ◽  
pp. 15514 ◽  
Author(s):  
Louis Gagnon ◽  
Michèle Desjardins ◽  
Julien Jehanne-Lacasse ◽  
Louis Bherer ◽  
Frédéric Lesage

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