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Right-to-left shunt

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204:, and can manifest as late as adult life. This switch in blood flow direction is precipitated by pulmonary hypertension due to increased pulmonary blood flow in a left-to-right shunt. The right ventricle hypertrophies to compensate for this pulmonary hypertension, so the right ventricular pressure becomes higher than the pressure in the left ventricle. Because of this switch in the pressure gradient, blood starts flowing right to left, forming a right-to-left shunt. As with any right-to-left shunt, there is decreased blood flow to the lungs, resulting in decreased oxygenation of blood and 416: 461: 279:. Using high levels of inspired oxygen should have little effect on the dissolved O2 in the blood because highly oxygenated blood is diluted by shunted (low oxygenation) blood. 180:. In this way only one lung is oxygenated and oxygen-poor blood from the non-ventilated lung dilutes the oxygen level of blood returning from the lungs in the left ventricle. 445:
Because most reptiles have a single ventricle and all reptiles have both a right aortic arch and a left aortic arch, all reptiles have the capacity for right-to-left shunt.
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is a symptom of a right-to-left shunt. A right-to-left shunt results in decreased blood flow through the pulmonary system, leading to decreased blood oxygen levels (
578: 233:(aortic valve is enlarged and appears to arise from both the left and right ventricles instead of the left ventricle, as occurs in normal hearts) 931: 629: 251:
Outside of heart-related conditions, right-to-left shunts of the heart can be seen with Pulmonary Arteriovenous Malformations (PAVMs).
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Rao, PS (Aug 2013). "Consensus on timing of intervention for common congenital heart diseases: part II - cyanotic heart defects".
571: 240:(thickening of the muscular walls of the right ventricle, this is a result of the increased amount of work the heart has to do) 227:(narrowing of the pulmonary valve and outflow tract, obstructing blood flow from the right ventricle to the pulmonary artery) 166: 130: 93:
Small physiological, or "normal", shunts are seen due to the return of bronchial artery blood and coronary blood through the
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Krishnan, U; Rosenzweig, EB (Dec 2013). "Pulmonary arterial hypertension associated with congenital heart disease".
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A mnemonic to remember the conditions associated with right-to-left shunting involves the numbers 1-5, as follows:
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Differentiation between a right-to-left shunt and pulmonary disease is often aided clinically by the results of a
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can lead to right-to-left shunting. This occurs when the tip of the endotracheal tube is placed beyond the
46:. This terminology is used both for the abnormal state in humans and for normal physiological shunts in 681: 671: 617: 243: 193: 801: 769: 201: 926: 796: 587: 237: 188:
An uncorrected left-to-right shunt can progress to a right-to-left shunt; this process is termed
749: 728: 936: 839: 829: 648: 856: 834: 806: 735: 658: 197: 189: 8: 689: 595: 217: 160: 125: 507: 224: 35: 791: 542: 499: 177: 173: 154: 120: 67: 511: 921: 916: 534: 491: 230: 911: 851: 786: 764: 94: 220:, a congenital cardiac anomaly characterized by four co-existing heart defects. 276: 105:
Congenital defects can lead to right-to-left shunting immediately after birth:
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Cardiac shunt allowing blood to flow from the right heart to the left heart
894: 86: 39: 246:(a hole exists in the septum that divides the left and right ventricles) 906: 43: 264: 260: 205: 85:
is higher than left heart pressure and/or the shunt has a one-way
47: 411:{\displaystyle Q_{p}/Q_{s}=(CcO_{2}-CaO_{2})/(CcO_{2}-CvO_{2})} 31: 24: 267:). Hypoxemia manifests as cyanosis, causing "blue babies." 477: 475: 97:, which are deoxygenated, to the left side of the heart. 472: 292: 216:
The most common cause of right-to-left shunt is the
524: 410: 949: 572: 932:Anomalous aortic origin of a coronary artery 586: 62:there is an opening or passage between the 579: 565: 430:CvO2 is the mixed venous oxygen content. 424:CcO2 is the end-capillary oxygen content 53: 183: 167:Total anomalous pulmonary venous return 131:Total anomalous pulmonary venous return 950: 211: 560: 481: 427:CaO2 is the arterial oxygen content 58:A right-to-left shunt occurs when: 13: 667:Sinus venosus atrial septal defect 625:Transposition of the great vessels 14: 969: 282: 700:Atrioventricular septal defect 518: 455: 405: 367: 359: 321: 172:A mainstem intubation with an 149:Transposition of great vessels 116:Transposition of great vessels 1: 642:Persistent truncus arteriosus 613:Double outlet right ventricle 448: 142:Persistent truncus arteriosus 110:Persistent truncus arteriosus 605:Aortopulmonary septal defect 484:Indian Journal of Pediatrics 467:Dorland's Medical Dictionary 270: 7: 434: 421:Qp/Qs is the shunt fraction 254: 10: 974: 441:Reptile § Circulation 438: 871: 817: 757: 748: 716: 698: 682:Ventricular septal defect 680: 657: 603: 594: 539:10.1016/j.ccm.2013.08.011 527:Clinics in Chest Medicine 496:10.1007/s12098-013-1039-2 244:Ventricular septal defect 194:Ventricular septal defect 100: 588:Congenital heart defects 202:patent ductus arteriosus 927:Coronary artery anomaly 238:ventricular hypertrophy 750:Valvular heart disease 729:Cyanotic heart disease 672:Lutembacher's syndrome 412: 140:1 Combination Vessel: 937:Ventricular inversion 649:Aortopulmonary window 618:Taussig–Bing syndrome 462:"right-to-left shunt" 413: 54:Clinical Significance 736:Eisenmenger syndrome 659:Atrial septal defect 290: 198:Atrial septal defect 190:Eisenmenger syndrome 184:Eisenmenger syndrome 147:2 Vessels involved: 958:Medical terminology 690:Tetralogy of Fallot 596:Heart septal defect 218:Tetralogy of Fallot 212:Tetralogy of Fallot 161:Tetralogy of Fallot 126:Tetralogy of Fallot 21:right-to-left shunt 408: 225:Pulmonary stenosis 192:. This is seen in 144:(minimal cyanosis) 112:(minimal cyanosis) 945: 944: 867: 866: 807:Ebstein's anomaly 744: 743: 174:endotracheal tube 159:4 Tetra- prefix: 155:Tricuspid atresia 121:Tricuspid atresia 965: 922:Brugada syndrome 917:Crisscross heart 787:tricuspid valves 765:pulmonary valves 755: 754: 601: 600: 581: 574: 567: 558: 557: 551: 550: 522: 516: 515: 479: 470: 459: 417: 415: 414: 409: 404: 403: 385: 384: 366: 358: 357: 339: 338: 317: 316: 307: 302: 301: 231:Overriding aorta 973: 972: 968: 967: 966: 964: 963: 962: 948: 947: 946: 941: 912:Cor triatriatum 878:Underdeveloped 863: 813: 740: 712: 694: 676: 653: 590: 585: 555: 554: 523: 519: 480: 473: 460: 456: 451: 443: 437: 399: 395: 380: 376: 362: 353: 349: 334: 330: 312: 308: 303: 297: 293: 291: 288: 287: 285: 273: 257: 250: 214: 186: 103: 95:Thebesian veins 56: 17: 12: 11: 5: 971: 961: 960: 943: 942: 940: 939: 934: 929: 924: 919: 914: 909: 904: 899: 898: 897: 892: 887: 880:heart chambers 875: 873: 869: 868: 865: 864: 862: 861: 860: 859: 854: 844: 843: 842: 837: 832: 821: 819: 815: 814: 812: 811: 810: 809: 804: 799: 794: 784: 783: 782: 777: 772: 761: 759: 752: 746: 745: 742: 741: 739: 738: 733: 732: 731: 720: 718: 714: 713: 711: 710: 704: 702: 696: 695: 693: 692: 686: 684: 678: 677: 675: 674: 669: 663: 661: 655: 654: 652: 651: 645: 644: 639: 638: 637: 632: 622: 621: 620: 609: 607: 598: 592: 591: 584: 583: 576: 569: 561: 553: 552: 517: 471: 453: 452: 450: 447: 436: 433: 432: 431: 428: 425: 422: 407: 402: 398: 394: 391: 388: 383: 379: 375: 372: 369: 365: 361: 356: 352: 348: 345: 342: 337: 333: 329: 326: 323: 320: 315: 311: 306: 300: 296: 284: 283:Shunt equation 281: 277:hyperoxia test 272: 269: 256: 253: 248: 247: 241: 234: 228: 213: 210: 185: 182: 170: 169: 163: 157: 151: 145: 134: 133: 128: 123: 118: 113: 102: 99: 91: 90: 79: 55: 52: 15: 9: 6: 4: 3: 2: 970: 959: 956: 955: 953: 938: 935: 933: 930: 928: 925: 923: 920: 918: 915: 913: 910: 908: 905: 903: 900: 896: 893: 891: 888: 886: 883: 882: 881: 877: 876: 874: 870: 858: 857:regurgitation 855: 853: 850: 849: 848: 847:mitral valves 845: 841: 838: 836: 835:insufficiency 833: 831: 828: 827: 826: 825:aortic valves 823: 822: 820: 816: 808: 805: 803: 800: 798: 797:regurgitation 795: 793: 790: 789: 788: 785: 781: 778: 776: 775:insufficiency 773: 771: 768: 767: 766: 763: 762: 760: 756: 753: 751: 747: 737: 734: 730: 727: 726: 725: 724:Cardiac shunt 722: 721: 719: 715: 709: 708:Ostium primum 706: 705: 703: 701: 697: 691: 688: 687: 685: 683: 679: 673: 670: 668: 665: 664: 662: 660: 656: 650: 647: 646: 643: 640: 636: 633: 631: 628: 627: 626: 623: 619: 616: 615: 614: 611: 610: 608: 606: 602: 599: 597: 593: 589: 582: 577: 575: 570: 568: 563: 562: 559: 548: 544: 540: 536: 533:(4): 707–17. 532: 528: 521: 513: 509: 505: 501: 497: 493: 490:(8): 663–74. 489: 485: 478: 476: 469: 468: 463: 458: 454: 446: 442: 429: 426: 423: 420: 419: 418: 400: 396: 392: 389: 386: 381: 377: 373: 370: 363: 354: 350: 346: 343: 340: 335: 331: 327: 324: 318: 313: 309: 304: 298: 294: 280: 278: 268: 266: 262: 252: 245: 242: 239: 235: 232: 229: 226: 223: 222: 221: 219: 209: 207: 203: 199: 195: 191: 181: 179: 175: 168: 164: 162: 158: 156: 152: 150: 146: 143: 139: 138: 137: 132: 129: 127: 124: 122: 119: 117: 114: 111: 108: 107: 106: 98: 96: 88: 84: 80: 77: 73: 72:great vessels 69: 65: 61: 60: 59: 51: 49: 45: 41: 37: 33: 30:which allows 29: 26: 22: 902:Dextrocardia 717:Consequences 530: 526: 520: 487: 483: 465: 457: 444: 286: 274: 258: 249: 215: 187: 171: 153:3 Leaflets: 135: 104: 92: 81:right heart 75: 57: 20: 18: 895:Uhl anomaly 40:right heart 907:Levocardia 449:References 439:See also: 68:ventricles 44:left heart 387:− 341:− 271:Diagnosis 265:hypoxemia 165:5 Words: 70:, and/or 38:from the 952:Category 852:stenosis 840:bicuspid 830:stenosis 802:stenosis 770:stenosis 547:24267300 512:39106680 504:23640699 435:Reptiles 261:cyanosis 255:Symptoms 206:cyanosis 89:opening. 87:valvular 83:pressure 48:reptiles 792:atresia 780:absence 42:to the 25:cardiac 630:dextro 545:  510:  502:  259:Early 236:Right 200:, and 178:carina 101:Causes 885:right 872:Other 758:Right 508:S2CID 64:atria 32:blood 28:shunt 23:is a 890:left 818:Left 635:levo 543:PMID 500:PMID 36:flow 535:doi 492:doi 464:at 76:and 34:to 954:: 541:. 531:34 529:. 506:. 498:. 488:80 486:. 474:^ 208:. 196:, 74:; 66:, 50:. 19:A 580:e 573:t 566:v 549:. 537:: 514:. 494:: 406:) 401:2 397:O 393:v 390:C 382:2 378:O 374:c 371:C 368:( 364:/ 360:) 355:2 351:O 347:a 344:C 336:2 332:O 328:c 325:C 322:( 319:= 314:s 310:Q 305:/ 299:p 295:Q 78:,

Index

cardiac
shunt
blood
flow
right heart
left heart
reptiles
atria
ventricles
great vessels
pressure
valvular
Thebesian veins
Persistent truncus arteriosus
Transposition of great vessels
Tricuspid atresia
Tetralogy of Fallot
Total anomalous pulmonary venous return
Persistent truncus arteriosus
Transposition of great vessels
Tricuspid atresia
Tetralogy of Fallot
Total anomalous pulmonary venous return
endotracheal tube
carina
Eisenmenger syndrome
Ventricular septal defect
Atrial septal defect
patent ductus arteriosus
cyanosis

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