How I do it: direct pressure measurement in moyamoya bypass.

BACKGROUND: The direct quantitative measurement of donor and recipient pressures in patients with moyamoya vasculopathy (MMV) during superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery has yet to be reported in academic literature. METHOD: Using a wireless pressure wire, we describe our approach to measuring seven pressure parameters in MMV patients step-by-step. CONCLUSION: Direct intraluminal pressure measurement of donor and recipient arteries provides a practical and accurate means to quantify cerebral hemodynamic parameters in MMV patients, enhancing understanding of individualized hemodynamic changes pre- and post-surgery.

[Myocardial revascularization : Controversy over noninvasive and invasive detection of ischemia]. / Myokardiale Revaskularisation : Kontroverse um den nicht-invasiven und den invasiven Ischämienachweis.

With some exceptions, myocardial revascularization in patients with chronic coronary syndrome (CCS) is generally decided on the basis of the extent of myocardial ischemia. Current data indicate that a patient will benefit from revascularization if ischemia is present in more than 10% of the myocardium. Accordingly, all patients presenting with CCS should undergo a noninvasive ischemia test that can answer this question before diagnostic coronary angiography. In order to be able to make a recommendation for revascularization based on scientific data even in those patients who previously had no clear evidence of ischemia, e.g., because of discrepant findings, measurement of the hemodynamic significance of coronary stenoses with a lumen diameter reduction ≥ 50% should be performed during coronary angiography. A decision to revascularize based on hemodynamic significance was shown to be beneficial to patients in several studies.

Determination of the Optimal Measurement Point for Fractional Flow Reserve Derived From CTA Using Pressure Wire Assessment as Reference.

BACKGROUND. For clinical decision making, it was recently recommended that values of fractional flow reserve (FFR) derived from coronary CTA (FFRCT) be measured 1-2 cm distal to the stenosis, given the potential for overestimation of ischemia when FFRCT values at far distal segments are used. Supporting data are, however, lacking. OBJECTIVE. The purpose of the present study was to evaluate the diagnostic performance of FFRCT values measured 1-2 cm distal to the stenosis and at more distal locations relative to invasive FFR values. METHODS. FFRCT and invasive FFR values for 365 vessels in 253 patients identified from the Assessing Diagnostic Value of Noninvasive FFRCT in Coronary Care (ADVANCE) registry were prospectively assessed. FFRCT values were measured 1-2 cm distal to the stenosis and at the pressure wire position and far distal segments. The diagnostic accuracy of FFRCT was assessed on the basis of the ROC AUC. The AUC of FFRCT was calculated using FFRCT as an explanatory variable and an invasive FFR of 0.80 or less as the dichotomous dependent variable. RESULTS. The AUC of FFRCT values measured 1-2 cm distal to the stenosis (0.85; 95% CI, 0.80-0.88) was higher (p = .002) than that of FFRCT values measured at far distal segments (0.80; 95% CI, 0.76-0.84) and similar (p = .16) to that of FFRCT values measured at the pressure wire position (0.86; 95% CI, 0.81-0.89). FFRCT values measured 1-2 cm distal to the stenosis and at far distal segments had sensitivity of 87% versus 92% (p = .003), specificity of 73% versus 42% (p < .001), PPV of 75% versus 59% (p < .001), and NPV of 86% versus 85% (p = .72), respectively. Subgroup analyses of lesions of the left anterior descending coronary artery, left circumflex coronary artery, and right coronary artery all showed improved specificity and PPV (all p < .005) for FFRCT values measured 1-2 cm distal to the stenosis compared with values measured at the pressure wire position. However, the AUC was higher for measurements obtained 1-2 cm distal to the stenosis versus those obtained at far distal segments, for left anterior descending coronary artery lesions (p < .001) but not for left circumflex coronary artery lesions (p = .27) or right coronary artery lesions (p = .91). CONCLUSION. The diagnostic performance of FFRCT values measured 1-2 cm distal to the stenosis was higher than that of FFRCT values measured at far distal segments and was similar to that of FFRCT values measured at the pressure wire position in evaluating ischemic status, particularly for left anterior descending coronary artery lesions. CLINICAL IMPACT. The present study supports recent recommendations from experts to use FFRCT measured 1-2 cm distal to the stenosis, rather than measurements obtained at far distal segments, in clinical decision making.

In-flight angina pectoris; an unusual presentation.

BACKGROUND: An unusual case of typical angina which occurred on a long haul flight is presented. This case is notable as this was the index presentation, with no previous symptoms prior to this. Physiological changes at altitude can be marked, and include hypoxia, tachycardia and an increase in cardiac output. These changes were enough to expose underlying angina in our patient. CASE PRESENTATION: A 68 year old man presented with typical cardiac chest pain on a long haul flight. His symptoms first started 10-15 min after take-off and resolved on landing. This was his index presentation, and there were no similar symptoms in the past. Background history included hypercholesterolaemia and benign prostatic hypertrophy only. He led a rather sedentary lifestyle. A CT coronary angiogram showed significant disease in the proximal left anterior descending artery and proximal right coronary artery. He went on to have a coronary angiogram with invasive physiological measurements, which determined both lesions were physiologically significant. Both arteries were treated with drug eluting stents. Since treatment, he once again embarked on a long haul flight, and was completely asymptomatic. CONCLUSION: The presentation of symptoms in this individual was rather unusual, but clearly caused by significant coronary artery disease. Potentially his sedentary lifestyle was not enough in day-to-day activities to promote anginal symptoms. When his cardiovascular system was physiologically stressed during flight, brought about by hypoxia, raised sympathetic tone and increased cardiac output, symptoms emerged. In turn, when landing, with atmospheric conditions normalised, physiological stress was removed, and symptoms resolved. Clinically therefore, one should not exclude symptoms that occur with differing physiological states, such as stress and altitude, as they are also potential triggers for myocardial ischaemia, despite absence of day-to-day symptoms.

The relationship between the basal coronary translesional pressure ratio and fractional flow reserve.

AIM: Fractional flow reserve (FFR) allows for physiological definition of coronary lesion severity but requires induction of maximal coronary circulation hyperemia with administration of adenosine leading to coronary resistive vessel vasodilatation. However, the hyperemic response to adenosine, and therefore the calculation of FFR, may be affected by dysfunction of the coronary microvasculature. The aim was to define the relationship between basal Pd /Pa and FFR and identify lesion-independent predictors of the change in Pd /Pa with hyperemia. METHODS AND RESULTS: One hundred and sixty-six consecutive patients undergoing FFR measurement were prospectively enrolled (mean age 62.6 ± 10.3 years, 27% females). Basal Pd /Pa , FFR, and delta Pd /Pa (difference between basal Pd /Pa and FFR) were recorded. Independent predictors of delta Pd /Pa included angiographic lesion severity, lesion length, gender, body mass index, and total cholesterol:HDL cholesterol ratio. The best basal Pd /Pa cutoff value to predict lesion physiological significance was 0.87 (positive predictive value of 100% for an FFR value ≤0.80) and the best cutoff for nonsignificance was 0.93 (negative predictive value of 98% for an FFR value >0.80). CONCLUSION: The delta Pd /Pa may be affected by patient gender, body mass index, and cholesterol profile. A basal Pd /Pa value of ≥0.93 is highly predictive of an FFR >0.80. Conversely, a basal Pd /Pa value of ≤0.87 is highly predictive of an FFR ≤0.80. © 2017 Wiley Periodicals, Inc.

Fractional flow reserve and resting indices for coronary physiologic assessment: Practical guide, tips, and tricks.

Physiologic assessment using fractional flow reserve (FFR) to guide percutaneous coronary interventions (PCI) has been demonstrated to improve clinical outcomes, compared to angiography-guided PCI. Recently, resting indices such as resting Pd/Pa, "instantaneous wave-free ratio", and contrast medium induced FFR have been evaluated for the assessment of the functional consequences of coronary lesions. Herein, we review and discuss the use of FFR and other indices for the functional assessment of coronary lesions. This review will cover theoretical aspects, as well as practical points and common pitfalls related to coronary physiological assessment. © 2017 Wiley Periodicals, Inc.

Diagnostic accuracy of instantaneous wave free-ratio in clinical practice.

AIMS: To evaluate the correlation between iFR and FFR in real-world clinical practice. METHODS AND RESULTS: Retrospective, single-centre study of 229 consecutive pressure-wire studies (np = 158). Real-time iFR and FFR measurements were performed for angiographically borderline stenoses. Functionally significant stenoses were defined as iFR <0.86 or FFR ≤0.80. An iFR between 0.86 and 0.93 was considered within the grey zone (Hybrid approach). Median iFR and FFR (IQR) were 0.92 (0.87-0.95) and 0.83 (0.76-0.89), respectively. Pearson's correlation coefficient was 0.75 (P < 0.001). Bland-Altman plot showed a mean difference between iFR and FFR that remained consistent throughout the range of values. The optimal iFR cutoff was 0.91-sensitivity 80%, specificity 82% with ROC area under curve of 89%. Using the Hybrid iFR-FFR strategy, we demonstrated high accuracy of iFR results-sensitivity 95%, specificity 96%, PPV 95%, and NPV 96%. In addition, this method would have avoided adenosine in 56% of patients. Mean follow-up period was 17.2 (±3.4) months. All-cause mortality was 3.2% (np = 5) and repeat intervention was required in six lesions (2.6%). CONCLUSIONS: This study demonstrates that iFR is a valuable adjunct to FFR using the Hybrid iFR-FFR strategy in a real-world population. The use of adenosine may be avoided in about half the cases.

The use of the acute Pd/Pa drop after intracoronary nitroglycerin infusion to rule out significant FFR: CANICA (Can intracoronary nitroglycerin predict fractional flow reserve without adenosine?) multicenter study.

OBJECTIVE: Functional assessment of coronary artery stenosis is performed by measuring the fractional flow reserve (FFR) under hyperemic conditions (Adenosine). However, the use of adenosine portends limitations. OBJECTIVE: We sought to investigate the relationship and correlation between FFR and the Pd/Pa value obtained just after the intracoronary infusion (acute drop) of nitroglycerin (Pd/Pa-NTG) and if this parameter enhances diagnostic accuracy for FFR prediction compared to the resting baseline Pd/Pa. METHODS: We conducted a multicenter study including prospectively patients presenting intermediate coronary artery stenosis (30-70%) evaluated with pressure wire. Resting baseline Pd/Pa, Pd/Pa-NTG and FFR were measured. RESULTS: 283 patients (335 lesions) were included. Resting baseline Pd/Pa value was 0.72 to 1.0 (0.93 ± 0.04), Pd/Pa-NTG was 0.60 to 1.0 (0.87 ± 0.07) and FFR 0.55 to 1.0 (0.83 ± 0.08). The ROC curves for resting baseline Pd/Pa and for Pd/Pa-NTG, using a FFR ≤ 0.80 showed an AUC of 0.88 (95% CI: 0.84-0.92, P < 0.001) and 0.94 (95% CI: 0.92-0.96, P < 0.001) respectively. The optimal cutoff values of resting baseline Pd/Pa and Pd/Pa-NTG for an FFR > 0.80, were >0.96 and >0.88, respectively. These values were present in a 29.8% (n = 100) and a 47.1% (n = 158), of the total lesions. Scatter plots showed a better correlation and agreement points with Pd/Pa-NTG than resting baseline Pd/Pa. The cutoff value of Pd/Pa-NTG > 0.88 showed an excellent NPV (96.2% for FFR > 0.8 and 100% for FFR > 0.75) and sensitivity (95% for FFR > 0.8 and 100% for FFR > 0.75) which were consistently high across all the subgroups analysis. CONCLUSION: The cutoff value of acute Pd/Pa-NTG > 0.88 has a high NPV meaning adenosine-FFR can be avoided in almost half of lesions.

Assessment of recurrent mesenteric ischemia after stenting with a pressure wire.

Chronic mesenteric artery ischemia can be difficult to evaluate after stent placement. This case describes the use of a pressure wire to demonstrate the hemodynamic significance of in-stent restenosis. Papaverine was used to vasodilate the mesenteric bed, mimicking the post-prandial state. The study (arteriography with pressure wire) and retreatment (covered balloon-expandable stent) was driven by recurrent symptoms avoiding unnecessary ancillary testing.

Functional assessment of coronary stenoses: can we live without it?

When selecting coronary stenoses for interventional treatment, assessment of reversible ischaemia is paramount from a symptomatic as well as prognostic point of view. Fractional flow reserve (FFR) is now considered the gold standard for invasive assessment of ischaemia. By measuring FFR in the catheterization laboratory, one can accurately identify which lesions should be stented resulting in improved patient outcome in most elective clinical and angiographic conditions. Recently, in the European Society of Cardiology guidelines on coronary revascularization, FFR was upgraded to an IA classification in multivessel percutaneous coronary intervention. In this review paper, the rationale for routine measurement of FFR will be reviewed and studies supporting its integration into everyday practice will be highlighted.

Influence of the pressure wire on the fractional flow reserve calculation: CFD analysis of an ideal vessel and clinical patients with stenosis.

BACKGROUND AND OBJECTIVE: Fractional Flow Reserve (FFR) is generally considered the gold standard in hemodynamics to assess the impact of a stenosis on the blood flow. The standard procedure to measure involves the displacement of a pressure guide along the circulatory system until it is placed next to the lesion to be analyzed. The main objective of the present study is to analyze the influence of the pressure guide on the invasive FFR measurements and its implications in clinical practice. METHODS: We studied the influence of pressure wires on the measurement of Fractional Flow Reserve (FFR) through a combination of Computational Fluid Dynamics (CFD) simulations using 45 clinical patient data with 58 lesions and ideal geometries. The analysis is conducted considering patients that were subjected to a computer tomography and also have direct measurements using a pressure guide. Influence of the stenosis severity, degree of occlusion and blood viscosity has also been studied. RESULTS: The influence of pressure wires specifically affects severe stenosis with a lumen diameter reduction of 50 % or greater. This type of stenosis leads to reduced hyperemic flow and increased coronary pressure drop. Thus, we identified that the placement of wires during FFR measurements results in partial obstruction of the coronary artery lumen, leading to increased pressure drop and subsequent reduction in blood flow. The severity of low FFR values associated with severe stenosis may be prone to overestimation when compared to stenosis without severe narrowing. These results have practical implications, particularly in the interpretation of lesions falling within the "gray zone" (0,75-0,80). CONCLUSIONS: The pressure wire's presence significantly alters the flow on severe lesions, which has an impact on the FFR calculation. In contrast, the impact of the pressure wire appears to be reduced when the FFR is larger than 0.8. The findings provide critical information for physicians, emphasizing the need for cautious interpretation of FFR values, particularly in severe stenosis. It also offers insights into improving the correlation between FFRct models and invasive measurements by incorporating the influence of pressure wires.

Coronary protection using a pressure wire during transcatheter aortic valve implantation.

Coronary obstruction is a rare but life-threatening complication of transcatheter aortic valve implantation (TAVI). This article describes the case of a patient with severe aortic valve stenosis treated with TAVI, during which preventive coronary wiring using a pressure wire was performed for coronary protection. After the deployment of the transcatheter heart valve (THV), the values of the fractional flow reserve (FFR) and resting full-cycle ratio (RFR) remarkably decreased, although the findings of transesophageal echocardiography and coronary angiography did not suggest coronary obstruction. Intravascular ultrasound revealed severe stenosis in the left main trunk due to the displacement of the calcified native leaflets. The decrease in the FFR and RFR values after THV deployment led to a diagnosis of partial coronary obstruction, and percutaneous coronary intervention was successfully performed. In patients at a high risk for coronary obstruction, coronary protection with a pressure wire is useful for the diagnosis and prevention of coronary flow deterioration during TAVI. Functional assessment using a pressure wire before and after TAVI may contribute to the accurate diagnosis of coronary obstruction. Learning objective: Accurate diagnosis of coronary obstruction during transcatheter aortic valve implantation (TAVI) is important for successful management. In patients at a high risk for coronary obstruction, coronary protection with a pressure wire is useful for the diagnosis and prevention of coronary flow deterioration during TAVI. The remarkable decrease in the fractional flow reserve and resting full-cycle ratio values after the deployment of the transcatheter heart valve may suggest coronary obstruction.

Do changes in intracoronary pressure aid coronary spasm diagnosis using the spasm provocation test?

BACKGROUND: Although the spasm provocation test (SPT) can diagnose coronary spasms, it would be helpful if it could also predict their occurrence. AIM: To investigate whether coronary spasms can be predicted using changes in intracoronary artery pressure measured using a pressure wire during the SPT. METHODS: Seventy patients underwent SPTs with pressure-wire measurement of intracoronary artery pressure. During each SPT, the pressure wire was advanced into the distal portion of the right coronary artery (RCA) and left anterior descending coronary artery, and the ratio of intracoronary pressure to aortic pressure (Pd/Pa) was monitored. Coronary spasm was defined as an arterial narrowing of > 90% in response to the administration of acetylcholine (ACh), with chest symptoms and/or ischemic electrocardiographic changes. ACh was administered to the RCA at low, moderate, or high doses of 20, 50, or 80 µg, respectively, and to the left coronary artery (LCA) at low, moderate, or high doses of 50, 100, or 200 µg, respectively. Coronary arteries with coronary spasms at low doses of ACh were defined as group L, and those with coronary spasms at moderate or high doses were defined as group MH. Those who did not occur coronary spasms at any ACh dose were designated as group N. RESULTS: Among the 132 coronary arteries assessed using a pressure wire, there were 49 in group N, 25 in group L, and 58 in group MH. Baseline Pd/Pa was the lowest in group L (P = 0.001). The decrease in the Pd/Pa between baseline to low doses of ACh was lower in group MH than in group N (P < 0.001). A receiver-operating characteristics analysis showed that the cutoff baseline Pd/Pa value for predicting group L was 0.95, with a sensitivity of 0.600 (15/25) and a specificity of 0.713 (76/107) and that the cutoff value of Pd/Pa from baseline to low doses of ACh for predicting group MH was -0.04, with a sensitivity of 0.741 (43/58) and a specificity of 0.694 (34/49). CONCLUSION: These findings suggest that indices of intracoronary pressure during SPT may be useful means for predicting the occurrence of coronary spasms.

Pullback Pressure Gradient-An Emerging Concept in Patients with Coronary Artery Disease.

Fractional flow reserve fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) is currently recommended in the management of patients with stable coronary artery disease (CAD). Pullback pressure gradient (PPG) index is an emerging concept that provides a fully quantitative measure of the longitudinal distribution of CAD. It can be derived from FFR, as well as other non-hyperemic indices, and is a novel metric of assessing the focality or diffuseness of CAD. PPG adds a second domain to the assessment of CAD, beyond ischemia as measured by FFR, and may enable clinicians to better inform their patients about the status of their CAD but may also predict potential outcomes before revascularization. In this article, we will provide an in-depth review on the concept of PPG index and its correlation to pre and post revascularization ischemia. We will assess the relationship between PPG index and plaque characteristics and how this is translated into any difference in procedural and long-term clinical outcomes.

Use of a Pressure Wire for Automatically Correcting Artifacts in Phasic Pressure Tracings From a Fluid-Filled Catheter.

BACKGROUND/PURPOSE: Matching phasic pressure tracings between a fluid-filled catheter and high-fidelity pressure wire has received limited attention, although each part contributes half of the information to clinical decisions. We aimed to study the impact of a novel and automated method for improving the phasic calibration of a fluid-filled catheter by accounting for its oscillatory behavior. METHODS/MATERIALS: Retrospective analysis of drift check tracings was performed using our algorithm that corrects for mean difference (offset), temporal delays (timing), differential sensitivity of the manifold transducer and pressure wire sensor (gain), and the oscillatory behavior of the fluid-filled catheter described by its resonant frequency and damping factor (how quickly oscillations disappear after a change in pressure). RESULTS: Among 2886 cases, correcting for oscillations showed a large improvement in 28 % and a medium improvement in 41 % (decrease in root mean square error >0.5 mmHg to <1 or 1-2 mmHg, respectively). 96 % of oscillators were underdamped with median damping factor 0.27 and frequency 10.6 Hz. Fractional flow reserve or baseline Pd/Pa demonstrated no clinically important bias when ignoring oscillations. However, uncorrected subcycle non-hyperemic pressure ratios (NHPR) displayed both bias and scatter. CONCLUSIONS: By automatically accounting for the oscillatory behavior of a fluid-filled catheter system, phasic matching against a high-fidelity pressure wire can be improved compared to standard equalization methods. The majority of tracings contain artifacts, mainly due to underdamped oscillations, and neglecting them leads to biased estimates of equalization parameters. No clinically important bias exists for whole-cycle metrics, in contrast to significant effects on subcycle NHPR.

Using Physiology Pullback for Percutaneous Coronary Intervention Guidance: Is this the Future?

Modern coronary intervention requires integration of angiographic, physiologic, and intravascular imaging. This article describes the use and techniques needed to understand coronary physiology pullback data and how use it to make revascularization decisions. The article describes instantaneous wave-free ratio, fractional flow reserve, and the data that support their use and how they differ when used in tandem disease. Common practical mistakes and errors are discussed together with a brief review of the limited published research data.

A novel computational fluid dynamic method and validation for assessing distal cerebrovascular microcirculatory resistance.

BACKGROUND AND OBJECTIVE: The non-invasive assessment of microcirculatory resistance could improve the treatment of cerebrovascular stenosis. This study aimed to validate a novel computational strategy for determining the reference value of microcirculatory resistance in patients with cerebrovascular stenosis. METHODS: We reconstructed a patient-specific 3-dimensional model of the extracranial-intracranial arteries. A computational strategy incorporating patient-specific pressure-wire measurements was developed to estimate the blood flow rate and microcirculatory resistance. Throughout the computational fluid dynamics (CFD) simulation, the boundary conditions were adjusted according to the developed algorithm. Pearson correlation and Bland-Altman analyses were used to quantify the correlation and agreement between CFD calculations and transcranial Doppler (TCD) assessment. RESULTS: A strong correlation was found between the CFD-based and invasive distal pressure measurements (P<0.0001). Meanwhile, the CFD and TCD-based flow measurements were highly correlated (r = 0.853; P = 0.001). Furthermore, there was a correlation between the mean velocity measured by CFD and the mean velocity measured by TCD (r = 0.777; P<0.001). Good agreement was observed between the mass flow by CFD simulation and volumetric flow by TCD (P = 0.0266, mean difference: -0.7814 mmHg, limits of agreement, -4.0905 - 2.5276). However, the mean velocities from CFD simulation were in less agreement with those from the TCD assessment (P = 0.3992, mean difference, -0.0485; limits of agreement, -0.6141 - 0.5170). Results of the CFD simulation indicate that the flow resistance varies greatly between individuals. CONCLUSIONS: The computational strategy of incorporating patient-specific pressure-wire measurements may serve as an effective approach to evaluate the actual reference values of microcirculatory resistance. In addition, an individualized assessment of non-invasive flow resistance is necessary for the accurate determination of non-invasive cerebrovascular pressure.

Changes in the Treatment Strategy Following Intracoronary Pressure Wire in a Contemporaneous Real-Life Cohort of Patients With Intermediate Coronary Stenosis. Results From a Nationwide Registry.

BACKGROUND: Intracoronary pressure wire is useful to guide revascularization in patients with coronary artery disease. AIMS: To evaluate changes in diagnosis (coronary artery disease extent), treatment strategy and clinical results after intracoronary pressure wire study in real-life patients with intermediate coronary artery stenosis. METHODS: Observational, prospective and multicenter registry of patients in whom pressure wire was performed. The extent of coronary artery disease and the treatment strategy based on clinical and angiographic criteria were recorded before and after intracoronary pressure wire guidance. 12-month incidence of MACE (cardiovascular death, non-fatal myocardial infarction or new revascularization of the target lesion) was assessed. RESULTS: 1414 patients with 1781 lesions were included. Complications related to the procedure were reported in 42 patients (3.0 %). The extent of coronary artery disease changed in 771 patients (54.5 %). There was a change in treatment strategy in 779 patients (55.1 %) (18.0 % if medical treatment; 68.8 % if PCI; 58.9 % if surgery (p < 0.001 for PCI vs medical treatment; p = 0.041 for PCI vs CABG; p < 0.001 for medical treatment vs CABG)). In patients with PCI as the initial strategy, the change in strategy was associated with a lower rate of MACE (4.6 % vs 8.2 %, p = 0.034). CONCLUSIONS: The use of intracoronary pressure wire was safe and led to the reclassification of the extent of coronary disease and change in the treatment strategy in more than half of the cases, especially in patients with PCI as initial treatment.

Comparison of microcatheter and pressure wire for venous sinus manometric evaluation of patients with idiopathic intracranial hypertension.

BACKGROUND: Venous sinus manometry performed by microcatheter to assess candidacy for venous sinus stenting in patients with idiopathic cranial pressure (IIH) can be tiring, time-consuming and unreliable. Pressure wire is widely used to measure coronary pressure and evaluate coronary stenosis severity, but venous sinus manometry using the pressure guide wire has only been reported in one case, and few studies have examined the accuracy of this approach. OBJECTIVE: To compare venous manometry performed by microcatheter with by pressure wire under awake setting in patients with IIH. METHODS: The manometry results of 30 patients with IIH were recorded by Rebar-27 microcatheter and a pressure wire under awake setting. The mean venous pressures (MVPs) and trans-stenosis pressure gradients were obtained and compared between microcatheter and pressure wire. Paired t-test) were used to evaluate the data between the two groups. RESULTS: MVPs in superior sagittal sinus (SSS) and torcula were slightly higher with microcatheter, though without statistically significant differences (p > 0.05). MVPs in transverse sinus (TS) and sigmoid sinus (SS) were significantly higher with microcatheter (p < 0.05). Trans-stenotic pressure gradient with microcatheter was significantly higher than with pressure wire (p＜0.001). CONCLUSIONS: Intracranial venous pressure measured with the microcatheter and pressure wire showed a moderate difference. Compared with the traditional microcatheter method，the pressure wire is safe, fast and effective method to identify the patient needing intervention.

Unmasking the severity of aortic stenosis by pharmacological elimination of left ventricular outflow tract obstruction: a case report.

Background: Left ventricular outflow tract (LVOT) obstruction may occur with aortic stenosis (AS). However, the severity of AS is difficult to determine in this condition because the dynamic pressure gradient in LVOT obstruction influences the blood flow across the aortic valve. Case summary: A 74-year-old woman was referred to our hospital having complaints of exertional dyspnoea and chest pain. Transthoracic echocardiography demonstrated LVOT obstruction with peak pressure gradient of 93 mmHg and 'moderate' AS with 3.9 m/s peak velocity and mean pressure gradient of 26 mmHg. Coronary angiography did not indicate any significant coronary artery disease. The pressure gradients at LVOT and aortic valve were measured as 34 mmHg and 76 mmHg via a pressure wire-pullback analysis, respectively. Intravenous 2 mg propranolol and 70 mg cibenzoline were administered to minimize the LVOT obstruction. Subsequently, these pressure gradients changed to 2 mmHg and 96 mmHg, respectively. The patient was finally diagnosed with 'severe' AS concomitant with LVOT obstruction. Therefore, surgical aortic valve replacement and myectomy were performed to remove the double obstruction. Discussion: Herein, we present a case of 'double' LVOT obstruction due to dynamic myocardial component and fixed aortic component. Although the severity of AS is known to be influenced by LVOT obstruction, the present case is novel to demonstrate the phenomenon by using a pressure wire during pharmacological intervention. An accurate evaluation of the AS severity is important to provide adequate treatment. Therefore, the severity of AS should be evaluated while minimizing the LVOT obstruction.