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Marek Czosnyka - One of the best experts on this subject based on the ideXlab platform.
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optimal cerebral perfusion pressure via Transcranial Doppler in tbi application of robotic technology
Acta Neurochirurgica, 2018Co-Authors: Frederick A Zeiler, Marek Czosnyka, Peter SmielewskiAbstract:Individualized cerebral perfusion pressure (CPP) targets may be derived via assessing the minimum of the parabolic relationship between an index of cerebrovascular reactivity and CPP. This minimum is termed the optimal CPP (CPPopt), and literature suggests that the further away CPP is from CPPopt, the worse is clinical outcome in adult traumatic brain injury (TBI). Typically, CPPopt estimation is based on intracranial pressure (ICP)-derived cerebrovascular reactivity indices, given ICP is commonly measured and provides continuous long duration data streams. The goal of this study is to describe for the first time the application of robotic Transcranial Doppler (TCD) and the feasibility of determining CPPopt based on TCD autoregulation indices.
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Transcranial Doppler a stethoscope for the brain neurocritical care use
Journal of Neuroscience Research, 2018Co-Authors: Danilo Cardim, Karol P. Budohoski, Chiara Robba, Mypinder S Sekhon, Marek CzosnykaAbstract:Transcranial Doppler (TCD) ultrasonography is a noninvasive bedside monitoring technique that can evaluate cerebral blood flow hemodynamics in the intracranial arterial vasculature. TCD allows assessment of linear cerebral blood flow velocity, with a high temporal resolution and is inexpensive, reproducible, and portable. The aim of this review is to provide an overview of the most commonly used TCD derived signals and measurements used commonly in neurocritical care. We describe both basic (flow velocity, pulsatility index) and advanced concepts, including critical closing pressure, wall tension, autoregulation, noninvasive intracranial pressure, brain compliance, and cerebrovascular time constant; we also describe the clinical applications of TCD to highlight their utility in the diagnosis and monitoring of cerebrovascular diseases as the “stethoscope for the brain.”
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Transcranial Doppler monitoring of intracranial pressure plateau waves
Neurocritical Care, 2017Co-Authors: Danilo Cardim, Marek Czosnyka, Chiara Robba, Bernhard Schmidt, Joseph Donnelly, Corina Puppo, Peter SmielewskiAbstract:Background Transcranial Doppler (TCD) has been used to estimate ICP noninvasively (nICP); however, its accuracy varies depending on different types of intracranial hypertension. Given the high specificity of TCD to detect cerebrovascular events, this study aimed to compare four TCD-based nICP methods during plateau waves of ICP.
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non invasive monitoring of intracranial pressure using Transcranial Doppler ultrasonography is it possible
Neurocritical Care, 2016Co-Authors: Danilo Cardim, Peter Smielewski, Chiara Robba, Bernhard Schmidt, Joseph Donnelly, Brenno Caetano Troca Cabella, Michal Bohdanowicz, Xiuyun Liu, Manuel Cabeleira, Marek CzosnykaAbstract:Although intracranial pressure (ICP) is essential to guide management of patients suffering from acute brain diseases, this signal is often neglected outside the neurocritical care environment. This is mainly attributed to the intrinsic risks of the available invasive techniques, which have prevented ICP monitoring in many conditions affecting the intracranial homeostasis, from mild traumatic brain injury to liver encephalopathy. In such scenario, methods for non-invasive monitoring of ICP (nICP) could improve clinical management of these conditions. A review of the literature was performed on PUBMED using the search keywords ‘Transcranial Doppler non-invasive intracranial pressure.’ Transcranial Doppler (TCD) is a technique primarily aimed at assessing the cerebrovascular dynamics through the cerebral blood flow velocity (FV). Its applicability for nICP assessment emerged from observation that some TCD-derived parameters change during increase of ICP, such as the shape of FV pulse waveform or pulsatility index. Methods were grouped as: based on TCD pulsatility index; aimed at non-invasive estimation of cerebral perfusion pressure and model-based methods. Published studies present with different accuracies, with prediction abilities (AUCs) for detection of ICP ≥20 mmHg ranging from 0.62 to 0.92. This discrepancy could result from inconsistent assessment measures and application in different conditions, from traumatic brain injury to hydrocephalus and stroke. Most of the reports stress a potential advantage of TCD as it provides the possibility to monitor changes of ICP in time. Overall accuracy for TCD-based methods ranges around ±12 mmHg, with a great potential of tracing dynamical changes of ICP in time, particularly those of vasogenic nature.
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non invasive assessment of icp during infusion test using Transcranial Doppler ultrasonography
Fluids and Barriers of the CNS, 2015Co-Authors: Danilo Cardim, John D. Pickard, Marek Czosnyka, Chiara Robba, Joseph Donnelly, Brenno Caetano Troca Cabella, Matthew R Garnett, Zofia CzosnykaAbstract:Background Transcranial Doppler (TCD) based methods have been used to estimate ICP noninvasively (nICP), however their relative accuracy varies between different types of intracranial hypertension: vasogenic, CSF circulatory or secondary to brain volumetric changes (oedema, contusion, hematoma, etc). This study aimed to compare four nICP methods in a prospective cohort of hydrocephalus patients whose CSF dynamics was investigated using infusion tests involving controllable test-rise of ICP.
Peter Smielewski - One of the best experts on this subject based on the ideXlab platform.
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optimal cerebral perfusion pressure via Transcranial Doppler in tbi application of robotic technology
Acta Neurochirurgica, 2018Co-Authors: Frederick A Zeiler, Marek Czosnyka, Peter SmielewskiAbstract:Individualized cerebral perfusion pressure (CPP) targets may be derived via assessing the minimum of the parabolic relationship between an index of cerebrovascular reactivity and CPP. This minimum is termed the optimal CPP (CPPopt), and literature suggests that the further away CPP is from CPPopt, the worse is clinical outcome in adult traumatic brain injury (TBI). Typically, CPPopt estimation is based on intracranial pressure (ICP)-derived cerebrovascular reactivity indices, given ICP is commonly measured and provides continuous long duration data streams. The goal of this study is to describe for the first time the application of robotic Transcranial Doppler (TCD) and the feasibility of determining CPPopt based on TCD autoregulation indices.
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Transcranial Doppler monitoring of intracranial pressure plateau waves
Neurocritical Care, 2017Co-Authors: Danilo Cardim, Marek Czosnyka, Chiara Robba, Bernhard Schmidt, Joseph Donnelly, Corina Puppo, Peter SmielewskiAbstract:Background Transcranial Doppler (TCD) has been used to estimate ICP noninvasively (nICP); however, its accuracy varies depending on different types of intracranial hypertension. Given the high specificity of TCD to detect cerebrovascular events, this study aimed to compare four TCD-based nICP methods during plateau waves of ICP.
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non invasive monitoring of intracranial pressure using Transcranial Doppler ultrasonography is it possible
Neurocritical Care, 2016Co-Authors: Danilo Cardim, Peter Smielewski, Chiara Robba, Bernhard Schmidt, Joseph Donnelly, Brenno Caetano Troca Cabella, Michal Bohdanowicz, Xiuyun Liu, Manuel Cabeleira, Marek CzosnykaAbstract:Although intracranial pressure (ICP) is essential to guide management of patients suffering from acute brain diseases, this signal is often neglected outside the neurocritical care environment. This is mainly attributed to the intrinsic risks of the available invasive techniques, which have prevented ICP monitoring in many conditions affecting the intracranial homeostasis, from mild traumatic brain injury to liver encephalopathy. In such scenario, methods for non-invasive monitoring of ICP (nICP) could improve clinical management of these conditions. A review of the literature was performed on PUBMED using the search keywords ‘Transcranial Doppler non-invasive intracranial pressure.’ Transcranial Doppler (TCD) is a technique primarily aimed at assessing the cerebrovascular dynamics through the cerebral blood flow velocity (FV). Its applicability for nICP assessment emerged from observation that some TCD-derived parameters change during increase of ICP, such as the shape of FV pulse waveform or pulsatility index. Methods were grouped as: based on TCD pulsatility index; aimed at non-invasive estimation of cerebral perfusion pressure and model-based methods. Published studies present with different accuracies, with prediction abilities (AUCs) for detection of ICP ≥20 mmHg ranging from 0.62 to 0.92. This discrepancy could result from inconsistent assessment measures and application in different conditions, from traumatic brain injury to hydrocephalus and stroke. Most of the reports stress a potential advantage of TCD as it provides the possibility to monitor changes of ICP in time. Overall accuracy for TCD-based methods ranges around ±12 mmHg, with a great potential of tracing dynamical changes of ICP in time, particularly those of vasogenic nature.
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monitoring cerebral autoregulation after head injury which component of Transcranial Doppler flow velocity is optimal
Neurocritical Care, 2012Co-Authors: Karol P. Budohoski, Peter J Kirkpatrick, John D. Pickard, Marek Czosnyka, Marcel J.h. Aries, Matthias Reinhard, Peter Smielewski, Zofia CzosnykaAbstract:Background Cerebral autoregulation assessed using Transcranial Doppler (TCD) mean flow velocity (FV) in response to various physiological challenges is predictive of outcome after traumatic brain injury (TBI). Systolic and diastolic FV have been explored in other diseases. This study aims to evaluate the systolic, mean and diastolic FV for monitoring autoregulation and predicting outcome after TBI.
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Transcranial Doppler pulsatility index what it is and what it isn t
Neurocritical Care, 2012Co-Authors: Nicolás De Riva, Karol P. Budohoski, Peter Smielewski, Magdalena Kasprowicz, Christian Zweifel, Luzius A. SteinerAbstract:Background Transcranial Doppler (TCD) pulsatility index (PI) has traditionally been interpreted as a descriptor of distal cerebrovascular resistance (CVR). We sought to evaluate the relationship between PI and CVR in situations, where CVR increases (mild hypocapnia) and decreases (plateau waves of intracranial pressure—ICP).
Karol P. Budohoski - One of the best experts on this subject based on the ideXlab platform.
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Transcranial Doppler a stethoscope for the brain neurocritical care use
Journal of Neuroscience Research, 2018Co-Authors: Danilo Cardim, Karol P. Budohoski, Chiara Robba, Mypinder S Sekhon, Marek CzosnykaAbstract:Transcranial Doppler (TCD) ultrasonography is a noninvasive bedside monitoring technique that can evaluate cerebral blood flow hemodynamics in the intracranial arterial vasculature. TCD allows assessment of linear cerebral blood flow velocity, with a high temporal resolution and is inexpensive, reproducible, and portable. The aim of this review is to provide an overview of the most commonly used TCD derived signals and measurements used commonly in neurocritical care. We describe both basic (flow velocity, pulsatility index) and advanced concepts, including critical closing pressure, wall tension, autoregulation, noninvasive intracranial pressure, brain compliance, and cerebrovascular time constant; we also describe the clinical applications of TCD to highlight their utility in the diagnosis and monitoring of cerebrovascular diseases as the “stethoscope for the brain.”
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monitoring cerebral autoregulation after head injury which component of Transcranial Doppler flow velocity is optimal
Neurocritical Care, 2012Co-Authors: Karol P. Budohoski, Peter J Kirkpatrick, John D. Pickard, Marek Czosnyka, Marcel J.h. Aries, Matthias Reinhard, Peter Smielewski, Zofia CzosnykaAbstract:Background Cerebral autoregulation assessed using Transcranial Doppler (TCD) mean flow velocity (FV) in response to various physiological challenges is predictive of outcome after traumatic brain injury (TBI). Systolic and diastolic FV have been explored in other diseases. This study aims to evaluate the systolic, mean and diastolic FV for monitoring autoregulation and predicting outcome after TBI.
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Transcranial Doppler pulsatility index what it is and what it isn t
Neurocritical Care, 2012Co-Authors: Nicolás De Riva, Karol P. Budohoski, Peter Smielewski, Magdalena Kasprowicz, Christian Zweifel, Luzius A. SteinerAbstract:Background Transcranial Doppler (TCD) pulsatility index (PI) has traditionally been interpreted as a descriptor of distal cerebrovascular resistance (CVR). We sought to evaluate the relationship between PI and CVR in situations, where CVR increases (mild hypocapnia) and decreases (plateau waves of intracranial pressure—ICP).
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Critical Thresholds for Transcranial Doppler Indices of Cerebral Autoregulation in Traumatic Brain Injury
Neurocritical Care, 2011Co-Authors: Enrico Sorrentino, John D. Pickard, Karol P. Budohoski, Peter Smielewski, Magdalena Kasprowicz, Basil Matta, Marek CzosnykaAbstract:Background Transcranial Doppler-derived indices of cerebral autoregulation are related to outcome after TBI. We analyzed our retrospective material to identify thresholds discriminative of outcome for these indices. Methods 248 sedated and ventilated patients after head injury were eligible for the study. The indices of autoregulation derived from Transcranial Doppler were calculated as correlation coefficients of blood flow velocity with cerebral perfusion pressure (index Mx) or arterial blood pressure (index Mxa). 2 × 2 tables were created grouping patients according to survival–death or favorable–unfavorable outcomes and varying thresholds for Mx and Mxa. Pearson’s chi-square was calculated. Thresholds returning the highest chi-square value were assumed to have the best discriminative value between survival–death and favorable–unfavorable outcomes. Results Mx and Mxa demonstrated that worse autoregulation is associated with poorer outcome and greater mortality ( P = 0.0033 for Mx and P = 0.047 for Mxa). Both indices were more effective for prediction of favorable outcome than mortality. Chi-square for Mx showed a double peak with thresholds at 0.05 and 0.3. Mxa had only one peak at 0.3. Peak chi-square for Mx (11.3) was greater than for Mxa (8.7), indicating that Mx was a better discriminant of outcome than Mxa. Conclusions We propose that Mx greater than 0.3 indicates definitely disturbed autoregulation and lower than 0.05 good autoregulation. For values between 0.05 and 0.3 the state of autoregulation is uncertain.
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critical thresholds for Transcranial Doppler indices of cerebral autoregulation in traumatic brain injury
Neurocritical Care, 2011Co-Authors: Enrico Sorrentino, John D. Pickard, Karol P. Budohoski, Peter Smielewski, Magdalena Kasprowicz, Basil F Matta, Marek CzosnykaAbstract:Transcranial Doppler-derived indices of cerebral autoregulation are related to outcome after TBI. We analyzed our retrospective material to identify thresholds discriminative of outcome for these indices. 248 sedated and ventilated patients after head injury were eligible for the study. The indices of autoregulation derived from Transcranial Doppler were calculated as correlation coefficients of blood flow velocity with cerebral perfusion pressure (index Mx) or arterial blood pressure (index Mxa). 2 × 2 tables were created grouping patients according to survival–death or favorable–unfavorable outcomes and varying thresholds for Mx and Mxa. Pearson’s chi-square was calculated. Thresholds returning the highest chi-square value were assumed to have the best discriminative value between survival–death and favorable–unfavorable outcomes. Mx and Mxa demonstrated that worse autoregulation is associated with poorer outcome and greater mortality (P = 0.0033 for Mx and P = 0.047 for Mxa). Both indices were more effective for prediction of favorable outcome than mortality. Chi-square for Mx showed a double peak with thresholds at 0.05 and 0.3. Mxa had only one peak at 0.3. Peak chi-square for Mx (11.3) was greater than for Mxa (8.7), indicating that Mx was a better discriminant of outcome than Mxa. We propose that Mx greater than 0.3 indicates definitely disturbed autoregulation and lower than 0.05 good autoregulation. For values between 0.05 and 0.3 the state of autoregulation is uncertain.
John D. Pickard - One of the best experts on this subject based on the ideXlab platform.
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non invasive assessment of icp during infusion test using Transcranial Doppler ultrasonography
Fluids and Barriers of the CNS, 2015Co-Authors: Danilo Cardim, John D. Pickard, Marek Czosnyka, Chiara Robba, Joseph Donnelly, Brenno Caetano Troca Cabella, Matthew R Garnett, Zofia CzosnykaAbstract:Background Transcranial Doppler (TCD) based methods have been used to estimate ICP noninvasively (nICP), however their relative accuracy varies between different types of intracranial hypertension: vasogenic, CSF circulatory or secondary to brain volumetric changes (oedema, contusion, hematoma, etc). This study aimed to compare four nICP methods in a prospective cohort of hydrocephalus patients whose CSF dynamics was investigated using infusion tests involving controllable test-rise of ICP.
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monitoring cerebral autoregulation after head injury which component of Transcranial Doppler flow velocity is optimal
Neurocritical Care, 2012Co-Authors: Karol P. Budohoski, Peter J Kirkpatrick, John D. Pickard, Marek Czosnyka, Marcel J.h. Aries, Matthias Reinhard, Peter Smielewski, Zofia CzosnykaAbstract:Background Cerebral autoregulation assessed using Transcranial Doppler (TCD) mean flow velocity (FV) in response to various physiological challenges is predictive of outcome after traumatic brain injury (TBI). Systolic and diastolic FV have been explored in other diseases. This study aims to evaluate the systolic, mean and diastolic FV for monitoring autoregulation and predicting outcome after TBI.
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Critical Thresholds for Transcranial Doppler Indices of Cerebral Autoregulation in Traumatic Brain Injury
Neurocritical Care, 2011Co-Authors: Enrico Sorrentino, John D. Pickard, Karol P. Budohoski, Peter Smielewski, Magdalena Kasprowicz, Basil Matta, Marek CzosnykaAbstract:Background Transcranial Doppler-derived indices of cerebral autoregulation are related to outcome after TBI. We analyzed our retrospective material to identify thresholds discriminative of outcome for these indices. Methods 248 sedated and ventilated patients after head injury were eligible for the study. The indices of autoregulation derived from Transcranial Doppler were calculated as correlation coefficients of blood flow velocity with cerebral perfusion pressure (index Mx) or arterial blood pressure (index Mxa). 2 × 2 tables were created grouping patients according to survival–death or favorable–unfavorable outcomes and varying thresholds for Mx and Mxa. Pearson’s chi-square was calculated. Thresholds returning the highest chi-square value were assumed to have the best discriminative value between survival–death and favorable–unfavorable outcomes. Results Mx and Mxa demonstrated that worse autoregulation is associated with poorer outcome and greater mortality ( P = 0.0033 for Mx and P = 0.047 for Mxa). Both indices were more effective for prediction of favorable outcome than mortality. Chi-square for Mx showed a double peak with thresholds at 0.05 and 0.3. Mxa had only one peak at 0.3. Peak chi-square for Mx (11.3) was greater than for Mxa (8.7), indicating that Mx was a better discriminant of outcome than Mxa. Conclusions We propose that Mx greater than 0.3 indicates definitely disturbed autoregulation and lower than 0.05 good autoregulation. For values between 0.05 and 0.3 the state of autoregulation is uncertain.
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critical thresholds for Transcranial Doppler indices of cerebral autoregulation in traumatic brain injury
Neurocritical Care, 2011Co-Authors: Enrico Sorrentino, John D. Pickard, Karol P. Budohoski, Peter Smielewski, Magdalena Kasprowicz, Basil F Matta, Marek CzosnykaAbstract:Transcranial Doppler-derived indices of cerebral autoregulation are related to outcome after TBI. We analyzed our retrospective material to identify thresholds discriminative of outcome for these indices. 248 sedated and ventilated patients after head injury were eligible for the study. The indices of autoregulation derived from Transcranial Doppler were calculated as correlation coefficients of blood flow velocity with cerebral perfusion pressure (index Mx) or arterial blood pressure (index Mxa). 2 × 2 tables were created grouping patients according to survival–death or favorable–unfavorable outcomes and varying thresholds for Mx and Mxa. Pearson’s chi-square was calculated. Thresholds returning the highest chi-square value were assumed to have the best discriminative value between survival–death and favorable–unfavorable outcomes. Mx and Mxa demonstrated that worse autoregulation is associated with poorer outcome and greater mortality (P = 0.0033 for Mx and P = 0.047 for Mxa). Both indices were more effective for prediction of favorable outcome than mortality. Chi-square for Mx showed a double peak with thresholds at 0.05 and 0.3. Mxa had only one peak at 0.3. Peak chi-square for Mx (11.3) was greater than for Mxa (8.7), indicating that Mx was a better discriminant of outcome than Mxa. We propose that Mx greater than 0.3 indicates definitely disturbed autoregulation and lower than 0.05 good autoregulation. For values between 0.05 and 0.3 the state of autoregulation is uncertain.
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relationship between Transcranial Doppler determined pulsatility index and cerebrovascular resistance an experimental study
Journal of Neurosurgery, 1996Co-Authors: Marek Czosnyka, Hugh K Richards, H Whitehouse, John D. PickardAbstract:✓ Clinical studies with Transcranial Doppler suggest that the pulsatility of the flow velocity (FV) waveform increases when the distal cerebrovascular resistance (CVR) increases. To clarify this relationship, the authors studied animal models in which the resistance may be decreased in a controlled manner by an increase in arterial CO2 tension, or by a decrease in cerebral perfusion pressure (CPP) in autoregulating animals. Twelve New Zealand white rabbits were anesthetized, paralyzed, and ventilated. Transcranial Doppler basilar artery FV, laser Doppler cortical blood flow, arterial pressure, intracranial pressure, and end-tidal CO2 concentration were measured continuously. Cerebrovascular resistance (CPP divided by laser Doppler cortical flux) and Gosling Pulsatility Index (PI, defined as an FV pulse amplitude divided by a timed average FV) were calculated as time-dependent variables for each animal. Four groups of animals undergoing controlled manipulations of CVR were analyzed. In Group I, arterial CO...
Jonathan M Tobis - One of the best experts on this subject based on the ideXlab platform.
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identification and quantification of patent foramen ovale mediated shunts echocardiography and Transcranial Doppler
Interventional cardiology clinics, 2017Co-Authors: Ahmed N Mahmoud, Jonathan M Tobis, Islam Y Elgendy, Nayan Agarwal, Mohammad K MojadidiAbstract:Once deemed benign, patent foramen ovale (PFO)-mediated right-to-left shunting has now been linked to stroke, migraine, and hypoxemia. Contrast transesophageal echocardiography is considered the standard technique for identifying a PFO, allowing visualization of the atrial septal anatomy and differentiation from non-PFO right-to-left shunts. Transthoracic echocardiography is the most common method for PFO imaging, being cost-effective, but has the lowest sensitivity. Transcranial Doppler is highly sensitive but is unable to differentiate cardiac from pulmonary shunts; it is the best method to quantitate shunt severity, being more sensitive than transthoracic or transesophageal echocardiography so is our preferred screening method for PFO.
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sensitivity of Transcranial Doppler versus intracardiac echocardiography in the detection of right to left shunt
Jacc-cardiovascular Imaging, 2010Co-Authors: Paul Poommipanit, Mostafa Helmy Shalaby, Rubine Gevorgyan, Chi Hong Tseng, Jonathan M TobisAbstract:OBJECTIVES: The purpose of this study was to understand the reason for variation in the sensitivity of different methods of detecting right-to-left shunts (RLS). BACKGROUND: Patent foramen ovale (PFO) is implicated in the pathogenesis of cryptogenic stroke, decompression illness, and migraine headaches. Intravenous agitated saline injections with tomographic imaging (transthoracic, transesophageal, and intracardiac echocardiography) has been used for detecting intracardiac shunts. Some patients with a high clinical suspicion of PFO have inconclusive echocardiographic study results. Transcranial Doppler (TCD) is an alternative method for detecting RLS that is not dependent on tomographic imaging. METHODS: Thirty-eight consecutive patients who were undergoing PFO closure had simultaneous Transcranial Doppler and intracardiac echocardiography performed. Agitated saline injections were performed at rest, with Valsalva maneuver, and with forced expiration into a manometer to 40 mm Hg before and after closure, as well as 3 or more months after closure. Right atrial pressures were measured in the periprocedural period, and RLS were graded according to standard methods during these maneuvers. RESULTS: Right atrial pressures were significantly higher with Valsalva maneuver compared with rest (before closure 21.6 +/- 11.9 mm Hg vs. 6.6 +/- 2.6 mm Hg, p < 0.001; after closure 28.4 +/- 13.9 mm Hg vs. 6.8 +/- 2.6 mm Hg, p < 0.001) and with manometer compared with Valsalva maneuver (before closure 38.7 +/- 6.6 mm Hg vs. 21.6 +/- 11.9 mm Hg, p < 0.001; after closure 44.0 +/- 9.5 mm Hg vs. 28.4 +/- 13.9 mm Hg, p < 0.001). Intracardiac echocardiography underestimated shunting in 34% of patients with Valsalva maneuver or manometer after closure compared with TCD. CONCLUSIONS: Transcranial Doppler with immediate feedback provided by forced expiration against a manometer to 40 mm Hg is more sensitive than echocardiographic imaging for the detection of RLS. These observations have significant implications for determining the incidence of RLS in patients with stroke or migraine.
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sensitivity of Transcranial Doppler versus intracardiac echocardiography in the detection of right to left shunt
Jacc-cardiovascular Imaging, 2010Co-Authors: Hohai Van, Paul Poommipanit, Mostafa Helmy Shalaby, Rubine Gevorgyan, Chi Hong Tseng, Jonathan M TobisAbstract:Objectives The purpose of this study was to understand the reason for variation in the sensitivity of different methods of detecting right-to-left shunts (RLS). Background Patent foramen ovale (PFO) is implicated in the pathogenesis of cryptogenic stroke, decompression illness, and migraine headaches. Intravenous agitated saline injections with tomographic imaging (transthoracic, transesophageal, and intracardiac echocardiography) has been used for detecting intracardiac shunts. Some patients with a high clinical suspicion of PFO have inconclusive echocardiographic study results. Transcranial Doppler (TCD) is an alternative method for detecting RLS that is not dependent on tomographic imaging. Methods Thirty-eight consecutive patients who were undergoing PFO closure had simultaneous Transcranial Doppler and intracardiac echocardiography performed. Agitated saline injections were performed at rest, with Valsalva maneuver, and with forced expiration into a manometer to 40 mm Hg before and after closure, as well as 3 or more months after closure. Right atrial pressures were measured in the periprocedural period, and RLS were graded according to standard methods during these maneuvers. Results Right atrial pressures were significantly higher with Valsalva maneuver compared with rest (before closure 21.6 ± 11.9 mm Hg vs. 6.6 ± 2.6 mm Hg, p Conclusions Transcranial Doppler with immediate feedback provided by forced expiration against a manometer to 40 mm Hg is more sensitive than echocardiographic imaging for the detection of RLS. These observations have significant implications for determining the incidence of RLS in patients with stroke or migraine.
