Normal human peak systolic blood flow velocities vary with age, cardiac output, and anatomic site. RVSP basically is the pressure generated by the right side of the heart when it pumps. In contrast, in the SEAS trial [5], the authors considered the discordance between AVA and MPG independently of any flow consideration. Uncommonly, increased peak systolic velocities can be seen in the vertebral artery V2 segment because of extrinsic compression by the spine or osteophytes in segment V2 and occasionally V3 ( Fig. The vertebral artery is readily identified by the prominent anatomic landmarks of the transverse processes of the cervical spine, which appear as bright echogenic lines that obscure imaging of deeper-lying tissues because of acoustic shadowing ( Fig. With the improvement in echocardiographic systems and combined two-dimensional/Doppler probe, the crystal probe tends to be disused and may appear outdated. Peak Velocity is the highest velocity attained during the same concentric lift phase. 7.1 ). This is often associated with changes in head or neck position, frequently referred to as "bow hunter's syndrome." The former study used the traditional method of grading stenosis, whereas the latter used the NASCET/ACAS approach. The higher the pressure in the pulmonary artery, the higher the pressure the right heart has to generate, which basically means the higher the RVSP. In the vast majority (21% of the overall population), the flow was normal, while low flow was observed in only 3% of the total population. It has been shown that peak systolic velocity decreases as the distance from the circle of Willis increases. Tortuosity also may render angle-corrected Doppler velocity measurements unreliable. This artery segment is typically quite straight, with minimal tortuosity and does not have any significant diameter changes. Ability to use duplex US to quantify internal carotid stenoses: fact or fiction? The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) comparing CAS with CEA demonstrated a similar reduction in stroke between the two procedures in symptomatic and asymptomatic patients. In others, magnetic resonance angiography (MRA) or computed tomographic angiography (CTA) may be performed in combination with sonography in cases where significant luminal narrowing is identified on the ultrasound examination or when the sonographic results are equivocal. FESC. Guy Lloyd: speaking engagements and advisory boards, Edwards, Philips, GE. severity based on measurement of peak and mean systolic velocities and shunt , quantification (eg, pulmonary artery flow volume (Qp) to ascending aortic flow volume (systemic flow or Qs) to provide . It is a cylindrical mechanical device which is placed over the penis and pumped; consequently, it creates a negative pressure vacuum to draw blood into the penis. N 26 Vertebral artery dissection is not commonly associated with elevated blood flow velocities in the absence of significant narrowing in either the true or the false lumen ( Fig. Methods Echocardiographic images were collected and post processed in 227 ACS patients. Classification of Patients with an Aortic Valve Area <1 cm (and preserved ejection fraction) into Four Groups according to Mean Pressure Gradient (MPG) and Stroke Volume Index (SVI), Figure 2. In addition, direct . The E-wave becomes smaller and the A-wave becomes larger with age. 9.1 ). The ultrasound criteria for estimating ICA stenosis severity are largely based on the results of the NASCET and ECST. In stenosis, a localized reduction in vascular radius increases resistance, causing increased PSV and EDV distal to the stenosed site 3,4. The SRU panel concluded that elevated PSV in the ICA and the presence of flow-limiting plaque are the primary parameters determining the severity of ICA stenosis. LVOT diameter should be measured in the parasternal long-axis view, using the zoom mode, in mid systole and repeated at least three to five times. That is why centiles are used. Blood flow velocities of the ECA are usually less clinically relevant; however, elevated ECA velocities may account for the presence of a bruit when there is no ICA stenosis. Thus, a woman with a score of 3,000 is very likely to present with severe AS, whereas a man with a score of 700 is very unlikely to present with severe AS. two phases. The ascending aorta has the highest average peak velocities of the major vessels; typical values are 150-175 cm/sec. Considering these technical issues, ultrasound assessment of vertebral artery origin stenosis should also rely on color Doppler and power Doppler imaging and analysis of the distal Doppler waveform alterations. (B) The vertebral artery has four main artery segments: V1, from the origin to entry into the neural foramina usually at cervical body six (in approximately 90% of cases); V2 coursing from C, Normal vertebral artery. Most surgical instrumentation interventions were fraught with high complication rates and minimal improvement in quality of life. The acoustic window between the transverse processes of the vertebral bodies can be used to visualize the vertebral arteries (segment V2) and to acquire color Doppler images and Doppler waveforms. (B) Rounded upstroke and decreased velocities (tardus-parvus) in the mid-upper right vertebral artery. Peak systolic velocity ranged from 1.2 to 3.3 cm/s, and peak diastolic velocity ranged from 1.6 to 4.5 cm/s. Symptoms of posterior circulation ischemia are typically varied, making it difficult to determine the potential contribution of vertebral-basilar insufficiency ( Table 9.1 ). It can identify a significantly elevated velocity in the proximal subclavian artery (i.e., >300 cm/s), as well as a. However, the implications and management of vertebral artery disease are less well studied. The proposed threshold of 35 ml/m is now widely accepted, even if its validation has never been carried out properly. The Velocity is taken with an angle for an accurate measurement.If an accurate angle (<60degrees) cannot be obtained then another measurement is taken with no angle so it can be compared to the renal artery at a stenosis site to do a renal artery:aorta ratio (RAR ratio). Qualitatively, the vertebral artery Doppler waveform should be similar to that of the internal carotid artery (ICA) because both directly supply the low-resistance intracranial vascular system. The E/A ratio is age-dependent. Transversely, the CCA is imaged from its proximal to distal aspects with gray-scale and color Doppler imaging. Although the surgical treatment of vertebral artery disease can be successful and relatively safe, patient selection may require consideration of internal carotid artery disease because symptoms of posterior circulation ischemia frequently improve following carotid artery endarterectomy or reconstruction. The minimum and maximum flow rates for the temporal window of interest were based on the cycle-averaged mean velocity in the Middle Cerebral Artery (MCA), and the peak systolic flow velocity in the MCA as predicted by a 30% damped older-adult flow waveform (Hoi et al. Discordant grading is defined either by an AVA <1 cm while MPG is 40 mmHg/PVel <4 m/sec, or by an AVA 1 cm and an MPG 40 mmHg/PVel 4 m/sec, the first situation being much more common. On the left, there is no elevation of peak systolic velocity with a normal ICA/CCA ratio of 0.84. Mean ratio peak systolic velocity in the DA-to-peak velocity across the pulmonary valve was 1.35 (SD 0.27). PSV is by far the most commonly used parameter because it is easily obtained and highly reproducible. Check for errors and try again. Plaque that contains an anechoic or hypoechoic focus may represent intraplaque hemorrhage or deposits of lipid or cholesterol. Using semi-automatic software, areas that are considered as calcification (defined by a tissue density >130 Hounsfield units) are highlighted in red. Smart NA, Cittadini A, Vigorito C. Exercise Training Modalities in Chronic Heart Failure: Does High Intensity Aerobic Interval Training Make the Difference? Note that peak systole is mildly exaggerated relative to end diastole (compare with, Effect of origin stenosis on distal vertebral artery waveform. S: peak systolic tissue doppler velocity; PECS: peak endocardial circumferential strain; PWWCS: peak whole . B., Egstrup K., Kesaniemi Y. If clinically indicated the waveform changes may be elicited by provocative maneuvers such as ipsilateral arm exercise or blood pressure cuff induced arm hyperemia. In this setting, a significant reduction in post-stenotic flow velocity is termed trickle flow 5. Further cranially, the V4 vertebral artery segment (extending from the point of perforation of the dura to the origin of the basilar artery) may be interrogated using a suboccipital approach and transcranial Doppler techniques (see Chapter 10 ), but segment V3 (the segment that extends from the arterys exit at C 2 to its entrance into the spinal canal) is generally inaccessible to duplex ultrasound during an extracranial cerebrovascular examination. [14] In case of discordant grading, after verification of potential error measurements, calcium scoring should be performed as the first-line test. Arterial duplex is utilized by most centers as a second line of testing. 7.2 ). Ultrasound diagnosis of vertebral artery origin stenosis is complicated by the frequent occurrence of considerable tortuosity in the proximal 1 to 2cm of the vertebral artery ( Fig. If the elevated thoracic pressure is maintained, blood pressure will be insufficient to support . Size-adjusted left ventricular outflow tract diameter reference values: a safeguard for the evaluation of the severity of aortic stenosis. Circ Cardiovasc Imaging. 4,5 In cats, the resultant increase in left ventricular (LV) afterload is associated with enlargement of the cardiac . Subsequent data from the NASCET reported improvement in outcome with CEA in patients with 50% to 69% stenosis, although the amount of improvement was far less than was the case with higher grade stenosis. Our mission: To reduce the burden of cardiovascular disease. In contrast, if positioned too close, within the flow acceleration, it will be responsible for an underestimation of AS severity. Medical Information Search Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Mitral E/A ratio The ratio between the E-wave and the A-wave is the E/A ratio. The left vertebral artery tends to be a dominant artery and would then have: Stenosis of the vertebral arteries produces hemodynamic abnormalities readily detected on Doppler waveforms. If the velocity is not dampened that strengthens the chance that the second finding is real. Low gradient severe aortic stenosis with preserved ejection fraction: reclassification of severity by fusion of Doppler and computed tomographic data. A study by Lee etal. Imaging of segment V2 is most easily accomplished by first obtaining a good longitudinal view of the mid common carotid artery (CCA) at the approximate level of the third through fifth cervical vertebrae. Modified from Grant EG, Benson CB, Moneta GL, etal. During a 2-year follow-up, ipsilateral PSV ECA increased following CAS, while the PSV ECA following CEA remained relatively unchanged ( Table 2; Fig. At the time the article was created Patrick O'Shea had no recorded disclosures. (2013) Interactive cardiovascular and thoracic surgery. In these same studies, after repetitive dosing, the half-life increased to a range from 4.5 to 12.0 hours (after less than 10 consecutive doses given 6 hours apart . Adequate Doppler evaluation of the vertebral artery V1 segment may not be possible due to vessel tortuosity and proximity to the clavicle. Ultrasound is the only imaging technique used in many facilities for selecting patients who might undergo carotid endarterectomy or stenting. Thresholds adjusted to height are currently missing. This can be quantified using the pulmonary velocity acceleration time (PVAT). Measurement of aortic valve calcification using multislice computed tomography: correlation with haemodynamic severity of aortic stenosis and clinical implication for patients with low ejection fraction. The difficulty in estimating the exact location of the plaque-free lumen of the proximal ICA introduced a great degree of interobserver error in estimating the degree of ICA stenosis. Kamperidis V., van Rosendael P. J., Katsanos S., van der Kley F., Regeer M., Al Amri I., Sianos G., Marsan N. A., Delgado V., & Bax J. J. Messika-Zeitoun D., Aubry M. C., Detaint D., Bielak L. F., Peyser P. A., Sheedy P. F., Turner S. T., Breen J. F., Scott C., Tajik A. J., & Enriquez-Sarano M. Cueff C., Serfaty J. M., Cimadevilla C., Laissy J P., Himbert D., Tubach F., Duval X., Lung B., Enriquez-Sarano M., Vahanian A., & Messika-Zeitoun D. Aggarwal S. R., Clavel M. A., Messika-Zeitoun D., Cueff C., Malouf J., Araoz P. A., Mankad R., Michelena H., Vahanian A., & Enriquez-Sarano M. Simard L., Cote N., Dagenais F., Mathieu P., Couture C., Trahan S., Bosse Y., Mohammadi S., Page S., Joubert P., & Clavel M. A. Clavel M. A., Messika-Zeitoun D., Pibarot P., Aggarwal S. R., Malouf J., Araoz P. A., Michelena H. I., Cueff C., Larose E., Capoulade R., Vahanian A., & Enriquez-Sarano M. Baumgartner H., Falk V., Bax J. J., De Bonis M., Hamm C., Holm P. J., Lung B., Lancellotti P., Lansac E., Munoz D. R., Rosenhek R., Sjogren J., Tornos Mas P., Vahanian A., Walther T., Wendler O., Windecker S., & Zamorano J. L. Bichat Hospital and University Paris VII, Paris, France; Barts Heart Centre, St. Bartholomews Hospital, West Smithfield, London,United Kingdom. Its maximum velocity is in the range of 0.8 -1.2 m/sec. Thus, it is expected that the AVA will increase and the number of patients with MPG <40 mmHg and AVA <1 cm will mathematically decrease. 128 (16): 1781-9. The initial screening test for renal artery stenosis is Doppler ultrasonography, and peak systolic velocity in the main renal artery is the best parameter for the detection of significant stenosis. Symptoms associated with atherosclerotic disease of the vertebral-basilar arterial system are diverse and often vague. Subaortic stenosis produces a high-velocity jet and a mean transvalvular pressure gradient (TMPG), and LVOT systolic blood flow disorder forms rich and complex vortex dynamics . The goal of this study is to determine the impact of 12 weeks of Lp299v supplementation (20 million cfu/day vs. placebo) on exercise capacity, circulating biomarkers of cardiac remodeling, quality of life, and vascular endothelial function in humans with heart failure and reduced ejection fraction (HFrEF) who have evidence of residual inflammation based on an elevated C-reactive protein level. The degree of carotid stenosis was characterized by measuring the size of the residual lumen and comparing it with the size of the original vessel lumen ( Fig. [9] The methodology is simple and widely available. MPG and PVel are highly correlated (collinear) and can be used almost interchangeably. Additional intrarenal scanning permits the diagnosis of RAS without direct imaging of the main renal artery. Multivariable linear and logistic regression were used to evaluate the relationship of cognitive function with carotid flow velocities and BP. The ECA waveform has a higher resistance pattern than the ICA. [7] Although attractive, such methodology suffers from important bias. If calcium scoring is below the threshold, AS is more likely to be non-severe and probably conservatively managed, although whether an intervention may provide a benefit still needs to be evaluated. Magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) have shown high accuracy, with duplex ultrasound having moderate accuracy, for the diagnosis of vertebral-basilar disease. The latter group is close to the low flow paradoxical severe AS described by the Quebec team. Elevated velocities can also be found with entities other than significant stenosis such as in young athletes, in high cardiac output states, in vessels supplying arteriovenous fistulas or arterial venous malformations, and in patients with carotid stenting. Mean peak oxygen consumption (VO 2 peak) at baseline was higher in the . (Reprinted with permission from the Radiological Society of North America: Grant EG, Duerinckx AJ, El Saden S, etal. Hypertension Stage 1 The ascending aorta has the highest average peak velocities of the major vessels; typical values are 150-175 cm/sec. Graph demonstrating the relationship between average peak systolic velocity (PSV) (y-axis) and percentage luminal narrowing as determined by contrast angiography using, North American Symptomatic Carotid Endarterectomy Trial (NASCET) method of measurement (x-axis). Discordant grading is defined based upon the observation that one parameter suggests a moderate AS while the other suggests a severe AS. With the use of computed tomography in the workup evaluation before TAVI, the anatomy of the aortic annulus has been well described. Previous studies have shown the importance of internal carotid plaque characterization (see Chapter 6 ). When pulmonary pressure and pulmonary vascular resistance are high the peak will occur earlier. Normal human peak systolic blood flow velocities vary with age, cardiac output, and anatomic site. THere will always be a degree of variation. Up to 20% to 30% of transient ischemic attacks and strokes may be due to disease of the posterior (vertebrobasilar) circulation. It is also possible to collect imaging and Doppler waveforms from the origin of the right vertebral artery in more than 92% to 94% of patients and from the origin of the left vertebral artery in approximately 60% to 86% of patients. 9.5 ). As expected, computed tomography and calcium scoring accurately classified patients with concordant grading, but more importantly 50% of the patients with discordant grading could be considered as having true severe AS, whereas 50% did not fulfil the criteria for severe AS, irrespective of flow calculation. In near occlusion (>99%), flow velocity indices become unreliable (may be high, low or absent) 4. (C) Magnetic resonance angiogram (MRA) shows a high-grade origin stenosis (, Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), on Ultrasound Assessment of the Vertebral Arteries, Ultrasound Assessment of the Vertebral Arteries, Ultrasound Assessment of Lower Extremity Arteries, The Role of Ultrasound in the Management of Cerebrovascular Disease, Anatomy of the Upper and Lower Extremity Arteries, Dizziness or vertigo (accompanied by other symptoms). 9.4 ) and a Doppler waveform is acquired. Cardiomyopathy is associated with structural and functional abnormalities of the ventricular myocardium and can be classified in two major groups: hypertrophic (HCM) and dilated (DCM) cardiomyopathy. The peak systolic velocity (PSV), end diastolic velocity (EDV), and time-averaged mean velocity (TMV) were measured and then corrected with the incident angle. The ACAS (Asymptomatic Carotid Atherosclerosis Study) also showed a reduction in incident stroke for asymptomatic patients with 60% or more stenotic lesions but, like the moderate range of stenoses in the NACSET, there was only a 5.8% reduction over 5 years. The first step is to look for error measurements. Fulfilling the precise and rigorous methodology presented above, the rate of patients with discordant grading is still between 20% and 30%, thus representing a common clinical problem. Peak systolic velocity (PSV)is an index measured in spectral Doppler ultrasound. Low cardiac output, for example, may have lower than expected velocities for a given degree of stenosis, and a ratio may actually be more reflective of the true degree of vessel narrowing. The most common, as mentioned earlier, is a dominant vertebral artery, more likely seen on the left side (see Fig. The ICA Doppler spectrum typically shows a low-resistance pattern. Carotid endarterectomy and stenting are also effective in managing symptomatic patients with high-grade carotid stenosis. Circulation, 2007, June 5. The recommendation is to move the Doppler sample up and down in order to obtain a nice Doppler trace with a closure click (possibly missing in very severe AS) without the opening click. 7.1 ). ADVERTISEMENT: Supporters see fewer/no ads. a. pressure is the highest at the carotid . Circulation, 2013, Oct 13. Proceedings of Ranimation 2017, the French Intensive Care Society International Congress A peak systolic velocity of 2.5 m/s or greater is indicative of a significant stenosis. The second source of error is the measurement of the aortic valve TVI obtained using continuous Doppler. In stepwise selection of polynomial terms, the linear, quadratic, and cubic correlations of .38, .17, and .22 for N and .45, .24, and .03 for C were found to be significant ( P <.02). Thus, among patients with an AVA below 1 cm, four groups can be identified (Figure 1). Thus, in the rest of the article we will use the MPG. Because of tortuosity, nonlaminar blood flow is commonly seen in the proximal vertebral artery, and kinking of the vessel may occur, causing an elevated peak systolic velocity. be assessed by phase-contrast determination of peak systolic velocity combined with the modified Bernoulli equation [85]. Changes that affect blood velocity like hypertension, pregnancy, overactive thyroid, infection etc could affect the results to a certain extent. The large peak velocity is the systolic phase, whereas the tail represents diastolic velocity. B., Edvardsen T., Goldstein S., Lancellotti P., LeFevre M., Miller F. Jr., & Otto C.M. Although the peak systolic velocity in the right ICA is slightly elevated to 130cm per second, there is normal ICA/CCA ratio measuring 0.95. Within the evaluated physiological range, there was no association between peak systolic velocity and fetal heart rate (P 0.64). What does a high peak systolic velocity mean? The mean exercise capacity achieved was 87%22% of predicted. Moderate (50% to 69%) internal carotid artery (, Receiver Operating Characteristic (ROC) curves for three Doppler velocity measurements to detect 70% or greater internal carotid artery (ICA) stenosis: peak systolic velocity (PSV =, Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window), Click to share on Google+ (Opens in new window), on Ultrasound Assessment of Carotid Stenosis, Ultrasound Assessment of Carotid Stenosis, Carotid Sonography: Protocol and Technical Considerations, Normal Findings and Technical Aspects of Carotid Sonography, Ultrasound Assessment of Lower Extremity Arteries, Ultrasound Assessment of the Vertebral Arteries. The fact that discordant grading is common and that low flow is rare but impacts on prognosis is of no help in assessing whether these patients truly presented severe AS. The mean elimination half-life in single-dose studies ranged from 2.8 to 7.4 hours. On a Doppler waveform, the peak systolic velocity corresponds to each tall peak in the spectrum window 1. This study confirms the high prevalence of patients with discordant grading and also shows that most often these patients presented with normal flow. Radiopaedia.org, the wiki-based collaborative Radiology resource SRU Consensus Conference Criteria for the Diagnosis of ICA Stenosis. 2 (H); (2) the use of 2 antihypertensive The right side of the heart has to pump into the lungs through a vessel called the pulmonary artery. To detect 60% reduction in renal artery diameter, a peak systolic velocity cutoff of 180 to 200 cm/s has been proposed. AAPM/RSNA physics tutorial for residents: topics in US: Doppler US techniques: concepts of blood flow detection and flow dynamics. 6), while an end-diastolic velocity greater than 150 cm/s suggests a degree of stenosis greater than 80%. The estimation of the original lumen is further complicated by the presence of a normal, but highly variable, region of dilatation, the carotid bulb. Introduction. All rights reserved. a. potential and kinetic engr. Results: Maximum hemodynamic condition does not necessarily occurred at peak systole . All three parameters are consistent with a 70% or greater stenosis according to the Society of Radiologists in Ultrasound (SRU) consensus criteria. In the coronal plane, a heel-toe maneuver is used to image the CCA from the supraclavicular notch to the angle of the mandible. In addition, the course of the V1 segment of the vertebral artery can be markedly tortuous thereby limiting proper Doppler angle correction and velocity measurements. The SRU consensus conference proposed the following Doppler velocity cut points: An internal to common carotid peak systolic velocity ratio <2.0, 125cm/s but <230cm/s peak systolic velocity of the ICA, An internal to common carotid PSV ratio 2.0 but <4.0, An end-diastolic ICA velocity 40cm/s but <100cm/s. 9.10 ). Leye M., Brochet E., Lepage L., Cueff C., Boutron I., Detaint D., Hyafil F., Lung B., Vahanian A., & Messika-Zeitoun D. de Monchy C. C., Lepage L., Boutron I., Leye M., Detaint D., Hyafil F., Brochet E., Lung B., Vahanian A., & Messika-Zeitoun D. Hachicha Z., Dumesnil J. G., Bogaty P., & Pibarot P. Paradoxical low-flow, low-gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival. The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology. The two values do typically correlate well with each other. Fourier transform and Nyquist sampling theorem. The vertebral artery is typically identified in the longitudinal plane, between the transverse processes of the cervical spine. Although this is an appropriate method in most vessels, there are several unique features of the proximal ICA that render this measurement technique problematic. Recommendations on the Echocardiographic Assessment of Aortic Valve Stenosis: A Focused Update from the European Association of Cardiovascular Imaging and the American Society of Echocardiography. Significantly increased vertebral artery peak systolic velocities can also be seen when one or both vertebral arteries are the compensatory mechanism for occlusive disease elsewhere in the cerebrovascular system ( Fig. CCA , Common carotid artery . 7.4 ). The right kidney is 12.2cm in length, the left kidney is 12.3cm. Sex differences in aortic valve calcification measured by multidetector computed tomography in aortic stenosis. Quantification is performed based on the Agatston score (expressed in arbitrary units [AU]) which rely on the area of calcification and of peak density. Specific cut-points based on the arteriographic correlative studies need to use the NASCET/ACAS measurement approach ( Fig. The ascending aorta has the highest average peak velocities of the major vessels; typical values are 150-175 cm/sec. To begin with, on all conventional angiographic studies, the original lumen is not actually seen. Echocardiographic assessment of the severity of aortic valve stenosis (AS) usually relies on peak velocity, mean pressure gradient (MPG) and aortic valve area (AVA), which should ideally be concordant. . Once this image has been obtained, a slight lateral rocking motion of the probe will bring the vertebral artery into view. The SRU consensus panel concluded that elevated PSV in the ICA and the presence of flow-limiting plaque are the primary parameters determining the severity of ICA stenosis. There is still ongoing debate as to whether the LVOT diameter should be measured at the level of leaflet insertion i.e. In general, for a given diameter of a residual lumen, the calculation of percent stenosis tends to be significantly higher using the pre-NASCET measurement method when compared with the NASCET method ( Fig. revisited an interesting approach to ICA ratio measurements where the ratio of the highest PSV at the site of the stenosis was compared with the normalized velocity in the distal ICA. This vertebral artery segment does not have any adjacent blood vessels except for the vertebral vein ( Fig.
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