Skip to main content

Specific Cardiovascular Diseases and Competitive Sports Participation: Coronary Anomalies and Myocardial Bridging at Risk of Sudden Death

  • Chapter
  • First Online:
Textbook of Sports and Exercise Cardiology

Abstract

Coronary arteries may be anomalous, with an incidence of 0.17% at autopsy or 1.2% at coronary angiography. They may be benign, but also a cause of congestive heart failure or sudden arrhythmic cardiac death. In the Cardiac Registry of the Congenital Heart Diseases of the Institute of Pathological Anatomy (1700 specimens) in Padua/Italy, isolated malformations of the coronary arteries account for 3.5% of observed alterations. In this chapter, coronary artery anomalies as a cause of sudden death in athletes will be treated. Among 75 cases of sudden death during sport activity, 16% were attributed to coronary artery anomalies:

  1. 1.

    Origin of a coronary artery from opposite wrong aortic sinus

  2. 2.

    Anomalous origin of the left circumflex coronary artery from the right sinus or coronary artery, with a retroaortic course.

  3. 3.

    High take-off

  4. 4.

    Myocardial bridging.

Only origin from the pulmonary artery is considered a certain cause, whereas anomalous origin of the left coronary artery from the right sinus with interarterial course should be considered as highly probable cause. High take-off, right coronary artery from the left sinus and myocardial bridging remain uncertain. Myocardial bridging is quite frequent in hypertrophic cardiomyopathy and may be a cause of myocardial infarction-ischemic scarring; however, sudden death in hypertrophic cardiomyopathy may also occur in the absence of myocardial bridging. Oddly enough, sudden death cases with myocardial bridging reported in the literature were indeed hypertrophic cardiomyopathy cases.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 89.00
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 119.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 169.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

References

  1. Basso C, Corrado D, Thiene G. Congenital coronary artery anomalies as an important cause of sudden death in the young. Cardiol Rev. 2001;9(6):312–7.

    CAS  PubMed  Google Scholar 

  2. Basso C, Corrado D, Thiene G. Coronary artery anomalies and sudden death. Card Electrophysiol Rev. 2002;6(1–2):107–11.

    PubMed  Google Scholar 

  3. Basso C, Maron BJ, Corrado D, Thiene G. Clinical profile of congenital coronary artery anomalies with origin from the wrong aortic sinus leading to sudden death in young competitive athletes. J Am Coll Cardiol. 2000;35(6):1493–501.

    CAS  PubMed  Google Scholar 

  4. Basso C, Perez-Pomares J, Thiene G, Houyel L. Coronary anomalies. In: Perez-Pomares J, Kelly R, editors. The ESC textbook of cardiovascular development. 1st ed. Oxford: OUP; 2018. p. 250–60.

    Google Scholar 

  5. Burke AP, Farb A, Virmani R, Goodin J, Smialek JE. Sports-related and non-sports-related sudden cardiac death in young adults. Am Heart J. 1991;121(2 Pt 1):568–75.

    CAS  PubMed  Google Scholar 

  6. Cheitlin MD, MacGregor J. Congenital anomalies of coronary arteries: role in the pathogenesis of sudden cardiac death. Herz. 2009;34(4):268–79.

    PubMed  Google Scholar 

  7. Corrado D, Thiene G, Cocco P, Frescura C. Non-atherosclerotic coronary artery disease and sudden death in the young. Br Heart J. 1992;68(6):601–7.

    CAS  PubMed  PubMed Central  Google Scholar 

  8. Frescura C, Basso C, Thiene G, Corrado D, Pennelli T, Angelini A, et al. Anomalous origin of coronary arteries and risk of sudden death: a study based on an autopsy population of congenital heart disease. Hum Pathol. 1998;29(7):689–95.

    CAS  PubMed  Google Scholar 

  9. Maron BJ, Doerer JJ, Haas TS, Tierney DM, Mueller FO. Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980-2006. Circulation. 2009;119(8):1085–92.

    PubMed  Google Scholar 

  10. Maron BJ, Haas TS, Doerer JJ, Thompson PD, Hodges JS. Comparison of U.S. and Italian experiences with sudden cardiac deaths in young competitive athletes and implications for preparticipation screening strategies. Am J Cardiol. 2009;104(2):276–80.

    PubMed  Google Scholar 

  11. Maron BJ, Shirani J, Poliac LC, Mathenge R, Roberts WC, Mueller FO. Sudden death in young competitive athletes. Clinical, demographic, and pathological profiles. JAMA. 1996;276(3):199–204.

    CAS  PubMed  Google Scholar 

  12. Taylor AJ, Rogan KM, Virmani R. Sudden cardiac death associated with isolated congenital coronary artery anomalies. J Am Coll Cardiol. 1992;20(3):640–7.

    CAS  PubMed  Google Scholar 

  13. Angelini P, Cheong BY, Lenge De Rosen VV, Lopez A, Uribe C, Masso AH, et al. High-risk cardiovascular conditions in sports-related sudden death: prevalence in 5,169 schoolchildren screened via cardiac magnetic resonance. Tex Heart Inst J. 2018;45(4):205–13.

    PubMed  PubMed Central  Google Scholar 

  14. Cheng Z, Wang X, Duan Y, Wu L, Wu D, Liang C, et al. Detection of coronary artery anomalies by dual-source CT coronary angiography. Clin Radiol. 2010;65(10):815–22.

    CAS  PubMed  Google Scholar 

  15. Duran C, Kantarci M, Durur Subasi I, Gulbaran M, Sevimli S, Bayram E, et al. Remarkable anatomic anomalies of coronary arteries and their clinical importance: a multidetector computed tomography angiographic study. J Comput Assist Tomogr. 2006;30(6):939–48.

    PubMed  Google Scholar 

  16. Engel HJ, Torres C, Page HL Jr. Major variations in anatomical origin of the coronary arteries: angiographic observations in 4,250 patients without associated congenital heart disease. Catheter Cardiovasc Diagn. 1975;1(2):157–69.

    CAS  Google Scholar 

  17. Harikrishnan S, Jacob SP, Tharakan J, Titus T, Kumar VK, Bhat A, et al. Congenital coronary anomalies of origin and distribution in adults: a coronary arteriographic study. Indian Heart J. 2002;54(3):271–5.

    CAS  PubMed  Google Scholar 

  18. Labombarda F, Coutance G, Pellissier A, Mery-Alexandre C, Roule V, Maragnes P, et al. Major congenital coronary artery anomalies in a paediatric and adult population: a prospective echocardiographic study. Eur Heart J Cardiovasc Imaging. 2014;15(7):761–8.

    PubMed  Google Scholar 

  19. Maron BJ, Leon MB, Swain JA, Cannon RO 3rd, Pelliccia A. Prospective identification by two-dimensional echocardiography of anomalous origin of the left main coronary artery from the right sinus of Valsalva. Am J Cardiol. 1991;68(1):140–2.

    CAS  PubMed  Google Scholar 

  20. Miller JA, Anavekar NS, El Yaman MM, Burkhart HM, Miller AJ, Julsrud PR. Computed tomographic angiography identification of intramural segments in anomalous coronary arteries with interarterial course. Int J Cardiovasc Imaging. 2012;28(6):1525–32.

    PubMed  Google Scholar 

  21. Norgaard BL, Leipsic J, Gaur S, Seneviratne S, Ko BS, Ito H, et al. Diagnostic performance of noninvasive fractional flow reserve derived from coronary computed tomography angiography in suspected coronary artery disease: the NXT trial (Analysis of Coronary Blood Flow Using CT Angiography: Next Steps). J Am Coll Cardiol. 2014;63(12):1145–55.

    PubMed  Google Scholar 

  22. Pelliccia A, Spataro A, Maron BJ. Prospective echocardiographic screening for coronary artery anomalies in 1,360 elite competitive athletes. Am J Cardiol. 1993;72(12):978–9.

    CAS  PubMed  Google Scholar 

  23. Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Catheter Cardiovasc Diagn. 1990;21(1):28–40.

    CAS  Google Scholar 

  24. Zeppilli P, dello Russo A, Santini C, Palmieri V, Natale L, Giordano A, et al. In vivo detection of coronary artery anomalies in asymptomatic athletes by echocardiographic screening. Chest. 1998;114(1):89–93.

    CAS  PubMed  Google Scholar 

  25. Angelini P. Normal and anomalous coronary arteries: definitions and classification. Am Heart J. 1989;117(2):418–34.

    CAS  PubMed  Google Scholar 

  26. Angelini P, Villason S, Chan AJ, Diez J. Normal and anomalous coronary arteries in humans. In: Angelini P, editor. Coronary artery anomalies: a comprehensive approach. Philadelphia: Lippincott, Williams & Wilkins; 1999. p. 27–150.

    Google Scholar 

  27. Muriago M, Sheppard MN, Ho SY, Anderson RH. Location of the coronary arterial orifices in the normal heart. Clin Anat. 1997;10(5):297–302.

    CAS  PubMed  Google Scholar 

  28. Banchi A. Le variazioni delle “arterie coronariae cordis” e la morfologia di questi vasi. Sperimentale. 1903;57:367–9.

    Google Scholar 

  29. Baroldi G, Scomazzoni G. Coronary circulation in the normal and the pathologic heart. Washington, DC: Armed Forces Institute of Pathology; 1965. p. 1–37.

    Google Scholar 

  30. Angelini P, Trivellato M, Donis J, Leachman RD. Myocardial bridges: a review. Prog Cardiovasc Dis. 1983;26(1):75–88.

    CAS  PubMed  Google Scholar 

  31. Caldani L, Caldani F. Icones anatomicae ex optimis neotericum operibus summa diligentia depromtae et collectae. In: Picotti J, editor. Venetiis ex Calcographia; 1810.

    Google Scholar 

  32. Davis JA, Cecchin F, Jones TK, Portman MA. Major coronary artery anomalies in a pediatric population: incidence and clinical importance. J Am Coll Cardiol. 2001;37(2):593–7.

    CAS  PubMed  Google Scholar 

  33. Kardos A, Babai L, Rudas L, Gaal T, Horvath T, Talosi L, et al. Epidemiology of congenital coronary artery anomalies: a coronary arteriography study on a central European population. Catheter Cardiovasc Diagn. 1997;42(3):270–5.

    CAS  Google Scholar 

  34. Yildiz A, Okcun B, Peker T, Arslan C, Olcay A, Bulent VM. Prevalence of coronary artery anomalies in 12,457 adult patients who underwent coronary angiography. Clin Cardiol. 2010;33(12):E60–4.

    PubMed  PubMed Central  Google Scholar 

  35. Ogden JA. Congenital anomalies of the coronary arteries. Am J Cardiol. 1970;25(4):474–9.

    CAS  PubMed  Google Scholar 

  36. Bland E, White P, Garland J. Congenital anomalies of the coronary arteries: report of an unusual case associated with cardic hypertrophy. Am Heart J. 1933;8:787–801.

    Google Scholar 

  37. Dodge-Khatami A, Mavroudis C, Backer CL. Anomalous origin of the left coronary artery from the pulmonary artery: collective review of surgical therapy. Ann Thorac Surg. 2002;74(3):946–55.

    PubMed  Google Scholar 

  38. Yau JM, Singh R, Halpern EJ, Fischman D. Anomalous origin of the left coronary artery from the pulmonary artery in adults: a comprehensive review of 151 adult cases and a new diagnosis in a 53-year-old woman. Clin Cardiol. 2011;34(4):204–10.

    PubMed  PubMed Central  Google Scholar 

  39. Chaitman BR, Lesperance J, Saltiel J, Bourassa MG. Clinical, angiographic, and hemodynamic findings in patients with anomalous origin of the coronary arteries. Circulation. 1976;53(1):122–31.

    CAS  PubMed  Google Scholar 

  40. Elias MD, Meza J, McCrindle BW, Brothers JA, Paridon S, Cohen MS. Effects of exercise restriction on patients with anomalous aortic origin of a coronary artery. World J Pediatr Congenit Heart Surg. 2017;8(1):18–24.

    PubMed  Google Scholar 

  41. Liberthson RR, Dinsmore RE, Fallon JT. Aberrant coronary artery origin from the aorta. Report of 18 patients, review of literature and delineation of natural history and management. Circulation. 1979;59(4):748–54.

    CAS  PubMed  Google Scholar 

  42. Lim JC, Beale A, Ramcharitar S. Medscape. Anomalous origination of a coronary artery from the opposite sinus. Nat Rev Cardiol. 2011;8(12):706–19.

    PubMed  Google Scholar 

  43. Lipsett J, Byard RW, Carpenter BF, Jimenez CL, Bourne AJ. Anomalous coronary arteries arising from the aorta associated with sudden death in infancy and early childhood. An autopsy series. Arch Pathol Lab Med. 1991;115(8):770–3.

    CAS  PubMed  Google Scholar 

  44. Palmieri V, Gervasi S, Bianco M, Cogliani R, Poscolieri B, Cuccaro F, et al. Anomalous origin of coronary arteries from the “wrong” sinus in athletes: Diagnosis and management strategies. Int J Cardiol. 2018;252:13–20.

    Google Scholar 

  45. Youniss MA, Ghoshhajra B, Bernard S, Bhatt AB, Aranki SF, MacGillivray TE, et al. Familial anomalous origin of right coronary artery from the left coronary sinus. Am J Cardiol. 2018;122(10):1800–2.

    PubMed  Google Scholar 

  46. Duran AC, Angelini A, Frescura C, Basso C, Thiene G. Anomalous origin of the right coronary artery from the left aortic sinus and sudden infant death. Int J Cardiol. 1994;45(2):147–9.

    CAS  PubMed  Google Scholar 

  47. Munoz-Guijosa C, Permanyer E, Leta R. Anomalous origin of right coronary artery from the left coronary sinus: sudden death and successful surgical reimplantation. Eur Heart J. 2012;33(11):1308.

    PubMed  Google Scholar 

  48. Roberts WC, Siegel RJ, Zipes DP. Origin of the right coronary artery from the left sinus of valsalva and its functional consequences: analysis of 10 necropsy patients. Am J Cardiol. 1982;49(4):863–8.

    CAS  PubMed  Google Scholar 

  49. Angelini P, Uribe C. Anatomic spectrum of left coronary artery anomalies and associated mechanisms of coronary insufficiency. Catheter Cardiovasc Interv. 2018;92(2):313–21.

    PubMed  Google Scholar 

  50. Arque JM, Thiene G, Cardo M, Franco D, Duran AC, Sans-Coma V. Anomalous origin of the left coronary artery from the nonfacing aortic sinus: a study in the Syrian hamster. Cardiovasc Pathol. 1993;2(1):35–9.

    CAS  PubMed  Google Scholar 

  51. Barth CW 3rd, Roberts WC. Left main coronary artery originating from the right sinus of Valsalva and coursing between the aorta and pulmonary trunk. J Am Coll Cardiol. 1986;7(2):366–73.

    PubMed  Google Scholar 

  52. Cheitlin MD, De Castro CM, McAllister HA. Sudden death as a complication of anomalous left coronary origin from the anterior sinus of Valsalva, A not-so-minor congenital anomaly. Circulation. 1974;50(4):780–7.

    CAS  PubMed  Google Scholar 

  53. Murphy DA, Roy DL, Sohal M, Chandler BM. Anomalous origin of left main cononary artery from anterior sinus of Valsalva with myocardial infarction. J Thorac Cardiovasc Surg. 1978;75(2):282–5.

    CAS  PubMed  Google Scholar 

  54. Adebo D, Jacobson Z, Harris MA. Anomalous origin of the right coronary artery from the posterior, non-coronary sinus of Valsalva diagnosed by cardiac magnetic resonance imaging. Cardiol Young. 2015;25(5):1006–8.

    PubMed  Google Scholar 

  55. Padalino MA, Franchetti N, Hazekamp M, Sojak V, Carrel T, Frigiola A, et al. Surgery for anomalous aortic origin of coronary arteries: a multicentre study from the European Congenital Heart Surgeons Association dagger. Eur J Cardiothorac Surg. 2019;56(4):696–703.

    PubMed  Google Scholar 

  56. Corrado D, Pennelli T, Piovesana P, Thiene G. Anomalous origin of the left circumflex coronary artery from the right aortic sinus of valsalva and sudden death. Cardiovasc Pathol. 1994;3(4):269–71.

    CAS  PubMed  Google Scholar 

  57. Page HL Jr, Engel HJ, Campbell WB, Thomas CS Jr. Anomalous origin of the left circumflex coronary artery. Recognition, antiographic demonstration and clinical significance. Circulation. 1974;50(4):768–73.

    PubMed  Google Scholar 

  58. Piovesana P, Corrado D, Contessotto F, Zampiero A, Camponeschi M, Lafisca N, et al. Echocardiographic identification of anomalous origin of the left circumflex coronary artery from the right sinus of Valsalva. Am Heart J. 1990;119(1):205–7.

    CAS  PubMed  Google Scholar 

  59. Loukas M, Andall RG, Khan AZ, Patel K, Muresian H, Spicer DE, et al. The clinical anatomy of high take-off coronary arteries. Clin Anat. 2016;29(3):408–19.

    PubMed  Google Scholar 

  60. Purvis J, Howe A, Morgan D. Aortic step: a clue to unusually high origin of right coronary artery. Heart. 2010;96(16):1334.

    CAS  PubMed  Google Scholar 

  61. Virmani R, Chun PK, Goldstein RE, Robinowitz M, McAllister HA. Acute takeoffs of the coronary arteries along the aortic wall and congenital coronary ostial valve-like ridges: association with sudden death. J Am Coll Cardiol. 1984;3(3):766–71.

    CAS  PubMed  Google Scholar 

  62. Alegria JR, Herrmann J, Holmes DR Jr, Lerman A, Rihal CS. Myocardial bridging. Eur Heart J. 2005;26(12):1159–68.

    PubMed  Google Scholar 

  63. Bourassa MG, Butnaru A, Lesperance J, Tardif JC. Symptomatic myocardial bridges: overview of ischemic mechanisms and current diagnostic and treatment strategies. J Am Coll Cardiol. 2003;41(3):351–9.

    PubMed  Google Scholar 

  64. Cheitlin MD. The intramural coronary artery: another cause for sudden death with exercise? Circulation. 1980;62(2):238–9.

    CAS  PubMed  Google Scholar 

  65. Corban MT, Hung OY, Eshtehardi P, Rasoul-Arzrumly E, McDaniel M, Mekonnen G, et al. Myocardial bridging: contemporary understanding of pathophysiology with implications for diagnostic and therapeutic strategies. J Am Coll Cardiol. 2014;63(22):2346–55.

    PubMed  PubMed Central  Google Scholar 

  66. Faruqui AM, Maloy WC, Felner JM, Schlant RC, Logan WD, Symbas P. Symptomatic myocardial bridging of coronary artery. Am J Cardiol. 1978;41(7):1305–10.

    CAS  PubMed  Google Scholar 

  67. Feldman AM, Baughman KL. Myocardial infarction associated with a myocardial bridge. Am Heart J. 1986;111(4):784–7.

    CAS  PubMed  Google Scholar 

  68. Mohlenkamp S, Hort W, Ge J, Erbel R. Update on myocardial bridging. Circulation. 2002;106(20):2616–22.

    PubMed  Google Scholar 

  69. Morales AR, Romanelli R, Boucek RJ. The mural left anterior descending coronary artery, strenuous exercise and sudden death. Circulation. 1980;62(2):230–7.

    CAS  PubMed  Google Scholar 

  70. Schwarz ER, Gupta R, Haager PK, vom Dahl J, Klues HG, Minartz J, et al. Myocardial bridging in absence of coronary artery disease: proposal of a new classification based on clinical-angiographic data and long-term follow-up. Cardiology. 2009;112(1):13–21.

    PubMed  Google Scholar 

  71. Gori F, Basso C, Thiene G. Myocardial infarction in a patient with hypertrophic cardiomyopathy. N Engl J Med. 2000;342(8):593–4.

    CAS  PubMed  Google Scholar 

  72. Basso C, Thiene G, Mackey-Bojack S, Frigo AC, Corrado D, Maron BJ. Myocardial bridging, a frequent component of the hypertrophic cardiomyopathy phenotype, lacks systematic association with sudden cardiac death. Eur Heart J. 2009;30(13):1627–34.

    PubMed  Google Scholar 

  73. Basso C, Aguilera B, Banner J, Cohle S, d'Amati G, de Gouveia RH, et al. Guidelines for autopsy investigation of sudden cardiac death: 2017 update from the Association for European Cardiovascular Pathology. Virchows Arch. 2017;471(6):691–705.

    PubMed  PubMed Central  Google Scholar 

  74. Basso C, Burke M, Fornes P, Gallagher PJ, de Gouveia RH, Sheppard M, et al. Guidelines for autopsy investigation of sudden cardiac death. Virchows Arch. 2008;452(1):11–8.

    PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Gaetano Thiene .

Editor information

Editors and Affiliations

Clinical Cases

Clinical Cases

1.1 Questions

  1. 1.

    A 53-year-old man was admitted to the coronary care unit complaining of chest pain. ECG showed ST-segment elevation in leads II, III, aVF, V5 and V6 as well as a ST-segment depression in V1-V4. Echocardiogram showed posterolateral left ventricular wall akinesia with preserved ejection fraction. There was an increase of the serum level of troponin. The patient was found dead 1 month later. At autopsy, no signs of obstructive coronary atherosclerotic disease were found. The left circumflex coronary artery took off at an acute angle from the anterior right aortic sinus, separately from the right coronary ostium, and run behind the aorta to reach the left atrioventricular groove. Moreover, a myocardial infarction was detected in the posterolateral wall of the left ventricle. Which imaging testing do you perform in this man to rule out coronary artery disease? In the guidelines of autopsy of sudden death, is this anomaly considered as a certain, a probable or an uncertain cause of death?

  2. 2.

    A 3-month-old male baby was found dead in his crib. At autopsy, the origin of the dominant right coronary artery was found originating from above the left coronary sinus with an acute angle take-off, and the proximal segment coursed intramurally within the aortic tunica media, passing between the aorta and the pulmonary trunk before reaching the right atrioventricular groove. Could a fetal echocardiography provide the correct diagnosis of this condition?

1.2 Answers

  1. 1.

    Coronary angiography is the gold standard method to provide an accurate study in vivo of coronary anatomy, to look at the origin and course of the proximal segments of right and left coronary artery, but also to rule out atherosclerotic coronary artery disease. Computed tomography angiography, due to its non-invasiveness and multiplanar reconstruction, is increasingly utilized for characterization of coronary artery origin anomalies. It provides a more accurate evaluation of the ostium as well as of the course and the presence of calcifications. Diagnostic methods such as computed tomographic angiography, nuclear magnetic resonance or coronarography are characterized by higher sensitivity and specificity as compared to echocardiography.

    The anomaly is considered an uncertain cause of sudden death; however, the subendocardial healed myocardial infarction in the setting of patently related coronary arteries strongly support a causal relationship.

  2. 2.

    Prenatal echocardiography does not allow visualization of the coronary artery origins in foetuses.

Rights and permissions

Reprints and permissions

Copyright information

© 2020 Springer Nature Switzerland AG

About this chapter

Check for updates. Verify currency and authenticity via CrossMark

Cite this chapter

Thiene, G., Rizzo, S., Frescura, C., Basso, C. (2020). Specific Cardiovascular Diseases and Competitive Sports Participation: Coronary Anomalies and Myocardial Bridging at Risk of Sudden Death. In: Pressler, A., Niebauer, J. (eds) Textbook of Sports and Exercise Cardiology. Springer, Cham. https://doi.org/10.1007/978-3-030-35374-2_21

Download citation

  • DOI: https://doi.org/10.1007/978-3-030-35374-2_21

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-030-35373-5

  • Online ISBN: 978-3-030-35374-2

  • eBook Packages: MedicineMedicine (R0)

Publish with us

Policies and ethics