ABC | Volume 110, Nº5, May 2018

Viewpoint Rosa et al Diagnosis of paradoxical aortic stenosis Arq Bras Cardiol. 2018; 110(5):484-486 1. Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP 3 rd , Guyton RA, et al. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/ AmericanHeart Association Task Force on Practice Guidelines. Circulation. 2014;129(23):e521-643. doi: 10.1161/CIR.0000000000000031. 2. Vahanian A, Alfieri O, Andreotti F, Antunes MJ, Barón-Esquivias G, Baumgartner H, et al; Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). Guidelines on the management of valvular heart disease (version 2012). Eur Heart J. 2012;33(19):2451-96. doi: 10.1093/eurheartj/ehs109. 3. Tarasoutchi F, Montera MW, Ramos AIO, et al. Atualização das Diretrizes Brasileiras de Valvopatias: Abordagem das Lesões Anatomicamente Importantes. Arq Bras Cardiol 2017; 109(6 Supl.2):1-34. doi: http://dx.doi . org/10.1590/S0066-782X2011002000001. 4. Minners J, Allgeier M, Gohlke-Baerwolf C, Kienzle RP, Neumann FJ, Jander N. Inconsistencies of echocardiographic criteria for the grading of aortic valve stenosis. Eur Heart J. 2008;29(8):1043-8. doi: 10.1093/ eurheartj/ehm543. 5. Hachicha Z, Dumesnil JG, Bogaty P, Pibarot P. Paradoxical low flow, low gradient severe aortic stenosis despite preserved ejection fraction is associated with higher afterload and reduced survival. Circulation. 2007;115(22):2856-64. doi: 10.1161/CIRCULATIONAHA.106.668681. 6. Pibarot P, Dumesnil JG. Low-flow, low-gradient aortic stenosis with normal and depressed left ventricular ejection fraction. J Am Coll Cardiol. 2012;60(19):1845-53. doi: 10.1016/j.jacc.2012.06.051. 7. Clavel MA, Burwash IG, Pibarot P. cardiac imaging for assessing low-gradient severe aortic stenosis. JACCCardiovasc Imaging. 2017;10(2):185-202. doi: 10.1016/j.jcmg.2017.01.002. 8. Eleid MF, Sorajja P, Michelena HI, Malouf JF, Scott CG, Pellikka PA. Flow-gradient patterns in severe aortic stenosis with preserved ejection fraction: clinical characteristics and predictors of survival. Circulation. 2013;128(16):1781-9. doi: 10.1161/CIRCULATIONAHA.113.003695. 9. Lancellotti P, Magne J, Donal E, Davin L, O’Connor K, Rosca M, et al. Clinical outcome in asymptomatic severe aortic stenosis. Insights from the new proposed aortic stenosis grading classification. J Am Coll Cardiol . 2012;59(3):235-43. doi: 10.1016/j.jacc.2011.08.072. Erratum in: J AmColl Cardiol. 2013;62(3):260. 10. Herrmann HC, Pibarot P, Hueter I, Gertz ZM, Stewart WJ, Kapadia S, et al. Predictors of mortality and outcomes of therapy in low flow severe aortic stenosis: a PARTNER trial analysis. Circulation . 2013;127(23):2316-26. doi: 10.1161/CIRCULATIONAHA.112.001290. References of aortic valve;whereVTI is time-velocity integral). TheVSVE dimension is usuallymeasuredwith a 2Dechocardiogram, assuming that theVSVE is circular. However, such a structure can often be elliptical, causing measurement errors. 7 3D echocardiogram is a promising test for more accurate evaluation of VSVE and AVA by planimetry, however, specific studies for the population with paradoxical AS are necessary for its routine indication. Twopoints are extremely important for the clinical cardiologist. First, in patients with small corporeal surface, a reduced AVAmay correspond to moderate AS. In this way wemust always index AVA by the corporeal surface (iAVA), being that an iAVA≤0.6 cm²/m² suggests important AS. In obese patients (BMI ≥ 30 kg/m²) we must assume a lower cut-off value (< 0.5 cm²/m²) so as not to overestimate the anatomical severity. 12 The second data that should be evaluated is systolic blood pressure in gradient measurement moment, which should be less than 140 mmHg. 1 Higher pressures contribute to underestimating the mean gradient and generate an increase in the valvulo-arterial impedance, a measure that estimates the ventricular afterload added to arterial and valvular overload ventricle, and it is also associated with mortality. 13 In summary, the clinical cardiologist should remember to index the AVA andmake sure that the systolic blood pressure was < 140 mmHg at the time of gradient measurement, while the echocardiographer should be attentive to errors in gradient measurement and measure the AVA by the planimetry. 3. Pathophysiology Confirmation: Finally, we must confirm the pathophysiology of AS and low-flow, low‑gradient. In developed countries, the main etiology of AS is degenerative, also known as calcific. Valvular calcification correlates with anatomic severity and values greater than 1650 AU, verified by computed tomography, suggest anatomically severe AS. 14 However, females may present the same anatomic severity as men, but with lower values of calcification, being advised to apply differentiated cutoff values for female patients (> 1200 AU). 15 Pathophysiology of low flow should be confirmed by stroke volume calculation, as previously described. In order to justify low gradient in a patient with severe AS, he must necessarily present a small cavity with stroke volume < 35 ml/m². 1-3,5-7 Thus, through this 3 steps algorithm, we help in the recognition of paradoxical AS anatomical severity, facilitating the clinician to identify the ideal moment for intervention in this difficult diagnosis entity. Author contributions Conception and design of the research, Analysis and interpretation of the data, Writing of the manuscript and Critical revision of the manuscript for intellectual content: Rosa VEE, Fernandes JRC, Lopes ASSA, Sampaio RO, Tarasoutchi F Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This study is not associatedwith any thesis or dissertationwork. 485