The solution - The second lesion should be sought. The carotid bulb and bifurcation should be imaged with gray scale and color Doppler. There is no need for contrast injection. In this setting, a significant reduction in post-stenotic flow velocity is termed trickle flow 5. PVel and MPG are obtained on the same image acquisition. In addition, ulcerated plaque that demonstrates a focal depression or break within the plaque is also more prone to plaque rupture and subsequent embolic event ( Fig. Spectral Doppler image confirms marked velocity elevation: PSV = 581 cm/s, end diastolic velocity ( EDV ) = 181 cm/s, and the PSV ratio is 8.2. In contrast, high resistance vessels (e.g. Peak systolic velocity (PSV) of the basal segments of the left ventricle from TDI is a robust and user independent parameter. Collateral c. A vessel that parallels another vessel; a vessel that 6. In diseased arteries, PSV increased proportionally with increasing stenosis and decreased to 0 cm/s at occlusion. It should be noted that the ECST continued to rely on the conventional method of stenosis measurement, and, although both the original NASCET and ECST confirmed the effectiveness of CEA, their methods of measuring ICA stenosis were quite different. All rights reserved. Most of the large carotid stenosis studies compared ultrasound with angiography as the gold standard while using the traditional non-NASCET method of grading carotid stenosis. A., Malbecq W., Nienaber C. A., Ray S., Rossebo A., Pedersen T. R., Skjaerpe T., Willenheimer R., Wachtell K., Neumann F. J., & Gohlke-Barwolf C. Outcome of patients with low-gradient 'severe' aortic stenosis and preserved ejection fraction. Visible narrowing on a color Doppler image accompanied by high-velocity color Doppler aliasing and poststenotic flow patterns are indicative of vertebral artery stenosis. 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. Up to 60% of patients have a dominant vertebral artery (i.e., with a larger diameter and higher blood flow velocity than the contralateral side [see Fig. The arteries of the hand have many anatomic variants and their evaluation may require a high level of technical expertise. The SRU consensus conference provided reasonable values that can be easily applied ( Table 7.1 ) and have been adopted by a large number of laboratories. Post date: March 22, 2013 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. In 20%-30% of patients, these parameters are discordant (usually AVA <1 cm and MPG <40 mmHg). Plaque with strong echolucent elements is generally termed heterogeneous plaque, which is considered unstable and more prone to embolize. The resistive indexes calculated from the peak-systolic and end- Carotid artery stenting (CAS) is the alternative treatment for stenosis that became widely available after the year 2000. If the velocity is not dampened that strengthens the chance that the second finding is real. Our mission: To reduce the burden of cardiovascular disease. Its a single point and will always be a much higher number then the mean. 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. Vasospasm systolic velocity minus end-diastolic velocity divided by the time-averaged peak velocity) 5. This is probably related to both a true increase in velocity as blood accelerates around a curve and difficulty in assigning a correct Doppler angle. Circulation, 2013, Oct 13. -
4. Review of Arterial Vascular Ultrasound. Echocardiography is the main method to assess AS severity. 15,
In the 1990s, many large, well-controlled, multicenter trials both in North America and Europe confirmed the effectiveness of CEA in preventing stroke in patients with ICA stenoses as compared with optimized medical therapy. Finally, the origin and proximal segment of the vertebral artery may be confused with other large branches arising from the proximal subclavian artery, such as the thyrocervical trunk. Secondary parameters such as elevated EDV in the ICA and elevated ICA/CCA PSV ratios further support the diagnosis of ICA stenosis if present. Systolic BP of 180 or higher means that you're in hypertensive crisis and should call your healthcare provider right away. ESC/EACTS guidelines for the management of valvular heart disease. In addition, direct . [2] The standard deviation was 1 mm, meaning that 50% of the patients were 1 mm above or below this theoretical value and that 95% of patients were 2 mm above or below. Measurement of LVOT diameter is probably the main source of error for the calculation of the AVA. 2. Boote EJ. These few published studies reported on the potential source for errors when using the standard ultrasound criteria after carotid stenting since the reduced compliance of stented carotid arteries. We excluded velocity peaks from the isovolumetric phases with end systole defined by the closing of the aortic valve in the three chamber projection. The current management of carotid atherosclerotic disease: who, when and how?. 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. What are the symptoms of a blocked renal artery? This should be less than 3.5:1. Most surgical instrumentation interventions were fraught with high complication rates and minimal improvement in quality of life. The ascending aorta has the highest average peak velocities of the major vessels; typical values are 150-175 cm/sec. Peak systolic velocity ( PSV ) exceeds 317 cm/s. A tardus-parvus waveform is indicative of a significant proximal vertebral artery stenosis. Positioning for the carotid examination. 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. The complex nature of discordant severe calcified aortic valve disease grading: new insights from combined Doppler echocardiographic and computed tomographic study. 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. Peak systolic velocity of 269 cm/s detected with an angle of 53 indicates moderate renal artery stenosis. Finally, an AVA below 1 cm may also be observed in small-sized patients. No external carotid artery stenosis is demonstrated. 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.
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.
9.1 ). Our understanding of the literature is that flow is a prognostic factor, whatever the reason or the cause of the depressed flow. B., Egstrup K., Kesaniemi Y. The ultrasound criteria for estimating ICA stenosis severity are largely based on the results of the NASCET and ECST. When traveling with their greatest velocity in a vessel (i.e. The diagnostic strata proposed by the Consensus Conference of the SRU (0% to 49%, 50% to 69%, and 70% but less than near occlusion) represent practical values that are clinically relevant and consistent with the NASCET. This Doppler waveform gives qualitative information and, once angle corrected, quantitative information on local hemodynamics. Homogeneous or echogenic plaques are believed to be stable and are unlikely to develop intraplaque hemorrhage or ulceration. 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. doppler ultrasound examination of fetal. Dr. 9.5 ). Among patients with discordant grading (AVA <1 cm and MPG <40 mmHg), those with low flow are much less frequent than those with normal flow. 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. The following sections describe duplex ultrasound evaluation techniques, the qualitative and quantitative data that can be obtained, and the interpretation and possible clinical significance of these results. On a Doppler waveform, the peak systolic velocity corresponds to each tall "peak" in the spectrum window 1. Aortic-valve stenosis--from patients at risk to severe valve obstruction. Similar cut-points had also been validated against angiography and produced a sensitivity of 95.3% and specificity of 84.4%. (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). The SRU consensus data represent a compromise between sensitivity and specificity and are based on cut points validated against ACAS/NASCET-based angiographic measurements of stenosis severity ( Table 7.2 ; Figs.
The following criteria are associated with at least a 50% diameter stenosis of the vertebral artery: peak systolic velocity above a threshold of between 108 and 140cm/s, depending on the series, more consistent criteria of peak systolic velocity ratio of 2.0 or more in a nontortuous segment. Radiopaedia.org, the wiki-based collaborative Radiology resource The most appropriate way of classifying patients is first to consider whether AVA and MPG are concordant, and secondly to consider the flow (stroke volume index). Study with Quizlet and memorize flashcards containing terms like The total energy of the vascular system has two primary components, which are ? Documentation of direction of blood flow and appearance of the spectral waveform are important to ensure that blood flow direction is cephalad (toward the head) and maintained throughout the cardiac cycle. Sex differences in aortic valve calcification measured by multidetector computed tomography in aortic stenosis. Of note, the rare cases of discordant grading with an AVA >1 cm and an MPG >40 mmHg are often observed in patients with a bicuspid aortic valve and a large LVOT/annulus size. ), have velocities that fall outside the expected norm for either PSV or EDV. 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. It is also worth noting that the proposed thresholds are not 'magic numbers', but provide a probability of having or not having severe AS. Circ Cardiovasc Imaging. Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. Its maximum velocity is in the range of 0.8 -1.2 m/sec. However, stenoses in other carotid artery segments such as the distal ICA (an area not typically well seen on routine carotid ultrasound), the common carotid artery (CCA), or the innominate artery (IA) may be equally significant. The last decade has seen this apparently easy and straightforward classification shaken up by the observation that up to one-third of patients present with discordant AS grading, and by the identification of a subset with paradoxical low-flow, low-gradient severe aortic stenosis despite preserved ejection fraction. Mean of maximum cerebral velocity readings are obtained, and results are classified . In complete occlusion, PSV and EDV are absent 4. While this is not a major problem in peripheral arteries when the original lumen is visible on both sides of a stenosis, lesions at the origin of the ICA typically do not have a normal lumen on both sides. Elevated blood flow velocities in the ECA are not considered clinically important except that they can explain the presence of a clinically detected carotid bruit. There is no obvious cut point to indicate an ideal threshold. What does a high peak systolic velocity mean? Aortic Stenosis Grades of Severity as Assessed Using Echocardiography and Computed Tomography (calcium scoring). Flow consideration has added a supplementary level of confusion. The highest point of the waveform is measured. 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. From these, the ICA/CCA ratio can be automatically calculated, typically with the PSV measurement from the distal CCA in the ratio, because velocity measurements in the proximal CCA may be slightly elevated because of the proximity of the thoracic aorta. 8 . The ECA waveform has a higher resistance pattern than the ICA. The aim was to investigate the prognostic value of PSV compared to EF, WMS, 2D strain and E/e'. aortic annulus or more apically, i.e. Thus, if peak velocity increases then so to will the mean velocity) Occasionally (in 3% to 5% of cases) the left vertebral artery has its origin from the aorta and not from the left subclavian artery. Peak plasma concentrations are reached between 1 and 2 hours after oral administration. The most common, as mentioned earlier, is a dominant vertebral artery, more likely seen on the left side (see Fig. More specifically, CT has clearly demonstrated that the LVOT and the aortic annulus are not circular but oval. Methods: This retrospective analysis includes patients with both DUS and fistulogram within 30 days. The mean elimination half-life in single-dose studies ranged from 2.8 to 7.4 hours. ADVERTISEMENT: Supporters see fewer/no ads. 3. 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). , and peak TR velocity > 2.8 m/sec. The normal superior mesenteric artery has a high-resistance waveform in the postprandial state and a peak systolic velocity of <2.75 m/s. 2010). ESC Scientific Document Group, 2017. Up to 30% of all major hemispheric events (stroke, transient ischemic attacks [TIA], or amaurosis fugax) are thought to originate from disease at the carotid bifurcation. . Subjects with MMSE score of 24 (25th percentile) was defined as low MMSE. RESULTS The former study used the traditional method of grading stenosis, whereas the latter used the NASCET/ACAS approach. Circulation, 2007, June 5. 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. 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. Specialized probes that have sufficient resolution to visualize small vessels and detect low blood flow velocity signals are often required. Large, multicenter trials both in North America and Europe confirmed the effectiveness of CEA in preventing stroke in patients with ICA stenoses compared with optimized medical therapy. 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. 1-3 Its -agonist effect is responsible for arterioconstriction, which is reflected clinically in a transiently increased arterial blood pressure. Conversely, blood flow velocities in the ICA contralateral to a high-grade stenosis or occlusion may be higher than expected if the vessel is the major supplier of collateral blood flow around the circle of Willis. 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. 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. It can identify a significantly elevated velocity in the proximal subclavian artery (i.e., >300 cm/s), as well as a. However, carotid stenting was associated with a higher incidence of periprocedural stroke, while CEA patients had a higher risk of perioperative myocardial infarction. Data from 202 patients showing changes in peak systolic velocity (PSV) sensitivity, specificity, and accuracy for the diagnosis of 70% or greater angiographically proven stenosis using NASCET grading system. [9] The methodology is simple and widely available. Therefore, the best way to address this issue is to use a quantitative and reliable flow-independent method for the assessment of AS severity, which is the remarkable characteristic of calcium scoring. The normal PVAT is > 130 msec. Evaluation and clinical implications of aortic valve calcification by electron beam computed tomography. 5 to 10 mm below the annulus. Therefore one should always consider the gray-scale and color Doppler appearance of the carotid segment in question including the plaque burden and visual estimates of vessel narrowing to determine whether all diagnostic features (both visual and velocity data) of a suspected stenosis are concordant. An important technical point to be made when calculating the ICA/CCA PSV ratio is that the denominator must be obtained from the distal CCA approximately 2 to 4cm proximal to the bifurcation. The peak systolic phase jet flow impacts the aortic valve flaps, leading to harm, scarring, excess flaps, . Methods Echocardiographic images were collected and post processed in 227 ACS patients. Methods of measuring the degree of internal carotid artery (. Velocities higher than 180 cm/s suggest the presence of a stenosis of more than 60% (Fig. It is important to keep in mind that BSA correction should be only undertaken in patients with small and large stature (small, elderly lady or male, professional basketball player), and should be avoided in those who are obese. 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. 9.5 ]). Since the trigonometric ratio that relates these values is the cosine function, it follows that the angle of insonation should be maintained at 60o1,2. (2019). Since the E-wave is normally larger than the A-wave, the ratio should be >1. Thus, in the rest of the article we will use the MPG. Within the evaluated physiological range, there was no association between peak systolic velocity and fetal heart rate (P 0.64). Results of a recent prospective study suggest that endovascular treatment of origin vertebral artery stenosis may not have clinical benefit. Intervention is recommended in symptomatic patients with proven severe AS and low gradient, as for patients with classic severe AS. With the improvement in echocardiographic systems and combined two-dimensional/Doppler probe, the crystal probe tends to be disused and may appear outdated. These values were determined by consensus without specific reference being available. The right kidney is 12.2cm in length, the left kidney is 12.3cm. If clinically indicated the waveform changes may be elicited by provocative maneuvers such as ipsilateral arm exercise or blood pressure cuff induced arm hyperemia. S: peak systolic tissue doppler velocity; PECS: peak endocardial circumferential strain; PWWCS: peak whole . The human cardiovascular system (CVS) undergoes severe haemodynamic alterations when experiencing orthostatic stress [1,2], that is when a subject either stands up, sits or is tilted head-up from supine on a rotating table.Among the most widely observed responses, clinical trials have shown accelerated heart rhythm and reduced circulating blood volume (cardiac output . The SRU criteria were derived from multiple studies reflecting different velocity parameters including the PSV, the ratio of PSV in the ICA to that in the ipsilateral distal CCA (i.e., the ICA PSV/CCA PSV ratio), and end-diastolic velocity (EDV). An icon used to represent a menu that can be toggled by interacting with this icon. David Messika-Zeitoun1, MD, PhD; Guy Lloyd2, MD, FRCP. First, it is well established that echocardiography underestimates the measurement of the LVOT annulus by 1 to 2 millimetres. Dexmedetomidine (DXM) is a sedative, muscular relaxant, and analgesic drug in common use in veterinary medicine. Aortic valve calcium scoring is a quantitative and flow-independent method of assessing AS severity (recommended thresholds are 2,000 in men and 1,250 in women). By the Doppler equation, it is noted that the magnitude of the Doppler shiftis proportional to the cosine of the angle (of insonation) formed between the ultrasound beam and the axis of blood flow 2. Why Is Aortic Pressure High. Note the dropout of color Doppler flow signals in the regions of acoustic shadowing (, Normal Doppler velocity waveform from the midsegment (V2) of a vertebral artery (, (A) This magnetic resonance angiogram of the right side of the neck shows a relatively small right vertebral artery (, (A) Color and spectral Doppler image at the origin of a normal vertebral artery. That is why centiles are used. The more reliable approach to assessing the vertebral artery is to visualize it near the mid portion of the cervical spine, at the V2 segment of the vertebral artery, as it courses cranially through the foramina to the transverse processes of C 6 to C 2 ( Fig. Hypertension Stage 1 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. Your measurement is Multiples of Median The risk of anemia is highest in fetuses with a pre-transfusion peak systolic velocity of 1.5 times the median or higher. Although the so-called NASCET method may not truly reflect the degree of luminal narrowing at the site of stenosis, this method has the advantage of minimizing interobserver error. 7.1 ). Explanation When traveling with their greatest velocity in a vessel (i.e. (A) The approximate locations of the V1 and V2 segments of the vertebral artery are shown. [6] Among 1,704 patients with a valve area below 1 cm, 24% presented with discordant grading (AVA <1 cm and MPG <40 mmHg). The range of vertebral artery peak systolic velocities varies between 41 and 64cm/s. The diagnosis of stenotic disease affecting other parts of the carotid system may be clinically important and will also be discussed. To assess whether these patients truly present with severe AS, the calcium score should be measured using computed tomography (thresholds are 2,000 AU in males and 1,250 AU in females). Introduction. Low resistance vessels (e.g. Additional intrarenal scanning permits the diagnosis of RAS without direct imaging of the main renal artery. . In addition, results in symptomatic patients were conflicting with more studies arguing against CAS in patients with symptomatic stenosis and high medical risk. Reference article, Radiopaedia.org (Accessed on 05 Mar 2023) https://doi.org/10.53347/rID-78164, View Patrick O'Shea's current disclosures, see full revision history and disclosures, Factors that influence flow velocity indices, fetal middle cerebral arterial peak systolic velocity, end-diastolic velocity (Doppler ultrasound), iodinated contrast media adverse reactions, iodinated contrast-induced thyrotoxicosis, diffusion tensor imaging and fiber tractography, fluid attenuation inversion recovery (FLAIR), turbo inversion recovery magnitude (TIRM), dynamic susceptibility contrast (DSC) MR perfusion, dynamic contrast enhanced (DCE) MR perfusion, arterial spin labeling (ASL) MR perfusion, intravascular (blood pool) MRI contrast agents, single photon emission computed tomography (SPECT), F-18 2-(1-{6-[(2-[fluorine-18]fluoroethyl)(methyl)amino]-2-naphthyl}-ethylidene)malononitrile, chemical exchange saturation transfer (CEST), electron paramagnetic resonance imaging (EPR). Both renal veins are patent. Symptoms of posterior circulation ischemia are typically varied, making it difficult to determine the potential contribution of vertebral-basilar insufficiency ( Table 9.1 ). 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. There are a number of other hemodynamic conditions that might lead to elevated vertebral peak systolic velocities. This study will define the optimal Doppler-derived peak systolic velocity (PSV) and velocity ratio (VR) to identify >50% lesions in arteriovenous fistulas (AVF) and arteriovenous grafts (AVG). Doppler waveforms can be consistently obtained at both vertebral artery intervertebral segments and the right vertebral origin. 9.8 ). The ultrasound criteria for estimating ICA stenosis severity are largely based on the results of the NASCET and European Carotid Surgery Trials (ECST). Prof. Messika-Zeitoun: consultant for Edwards, Valtech, Mardil and Cardiawave. Check for errors and try again. Table 1. The current parameters used to grade the severity of ICA stenosis are based on the Society of Radiologists in Ultrasound (SRU) Consensus Statement in 2003. Prognosis of the Four Subsets as Defined in Figure 1. 7.4 ). Once an image of the vertebral artery has been obtained, the Doppler sample volume can be placed in the artery segment ( Fig. 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 . Gated computed tomography is performed from the apex to the base of the heart, including the aortic valve. 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). Unable to process the form. 4,5 In cats, the resultant increase in left ventricular (LV) afterload is associated with enlargement of the cardiac . Second, the prognostic value of the AVA has been established using echocardiographic evaluation, while the prognostic value of combined AVA calculation is uncertain. At angles >60o, the cosine function curves much more steeply,leading to a significant reduction in the accuracy of angle correction, and thus the accuracy of blood velocity indices such as PSV and end-diastolic velocity (EDV)1. The association of carotid atherosclerotic disease with symptomatic cerebrovascular disease (i.e., transient ischemic attacks), amaurosis fugax, and stroke, is well established. Modified from Grant EG, Benson CB, Moneta GL, etal. (2000) World Journal of Surgery. 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. RVSP basically is the pressure generated by the right side of the heart when it pumps. Calculation of the AVA relies on the measurement of three parameters; error measurement may occur in all three.
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