Left Septal Fascicular Block: Myth Or Reality?

MacAlpin, Rex N. (2003) Left Septal Fascicular Block: Myth Or Reality? [Journal (Paginated)]

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Anatomic studies have shown that the left bundle branch divides into three fascicles in most humans. Changes in the 12 lead ECG (electrocardiogram) due to conduction abnormalities of the left anterior fascicle and left posterior fascicle are now part of the standard repertoire of electrocardiographic interpretation. There are no standard criteria for detecting conduction defects involving the third left fascicle, the septal or median fascicle, and the very existence of such defects is still a matter of controversy. The purposes of this article are to review the available evidence on this subject, suggest electrocardiographic criteria for its recognition, and present examples which illustrate that left septal fascicular block does indeed exist as a specific entity. Left septal fascicular block is a polymorphic conduction defect which may explain some previously inadequately understood electrocardiographic abnormalities.

Item Type:Journal (Paginated)
Keywords:fascicular block; left septal fascicular block; intraventricular conduction defects; ventricular activation
Subjects:JOURNALS > Indian Pacing and Electrophysiology Journal
ID Code:4280
Deposited By:Indian Pacing and Electrophysiology, Journal
Deposited On:24 Apr 2005
Last Modified:11 Mar 2011 08:55

References in Article

Select the SEEK icon to attempt to find the referenced article. If it does not appear to be in cogprints you will be forwarded to the paracite service. Poorly formated references will probably not work.

1. Rosenbaum MB, Elizari M, Lazzari J. Los hemibloqueos. Buenos Aires: Editorial Paidos; 1968.

2. Rosenbaum MB, Elizari MV, Lazzari JO. The hemiblocks. Oldsmar: Tampa Tracings; 1970:94.

3. Surawicz B and Knilans TK. Chou's electrocardiography in clinical practice. 5th ed. Philadelphia: W.B. Saunders Co.; 2001: 11, 51, 106-21.

4. Alboni P. Intraventricular conduction disturbances. Boston: Martinus Nijhoff Publishers; 1981:57.

5. Schamroth L. The 12 lead electrocardiogram. Oxford: Blackwell; 1989:61, 69, 211.

6. Surawicz B. Electrophysiologic basis of ECG and cardiac arrhythmias. Baltimore: Williams & Wilkins; 1995:507, 517-8.

7. Tawara S. Das Reizleitungssystem des Säugetierherzens. Jena: Fischer; 1906:35, 201.

8. Massing, GK and James TN. Anatomical configuration of the His bundle and bundle branches in the human heart. Circulation 1976;53:609-21.

9. Uhley HN. The quadrafascicular nature of the peripheral conduction system. In: Dreifus L and Likoff, editors. Cardiac arrhythmais. New York, NY: Grune & Stratton; 1973:339-48.

10. Rossi I. Histopathology of the conducting system. G Ital Cardiol 1972;2:484-91.

11. Nakaya Y and Hiraga T. Reassessment of the subdivision block of the left bundle branch. Jpn Circulation J 1981;45:503-16.

12. Demoulin JC and Kulbertus HE. Histopathological examination of concept of left hemiblock. Br Heart J 1972;34:807-14.

13. Kulbertus HE and Demoulin J-C. The left hemiblocks: significance, prognosis and treatment. Schweiz med Wschr 1982;112:1579-84.

14. Anderson RH, Ho SY, Wharton J, Becker AE. Gross anatomy and microscopy of the conducting system. In: Mandel WJ, editor. Cardiac arrhythmias. Their mechanisms, diagnosis and management. 3rd edition. Philadelphia: J.B. Lippincott Co.; 1995:13-54.

15. Durrer D, van Dam R Th, Freud GE, Janse MJ, Meijler FL, Arzbaecher RC. Total excitation of the isolated human heart. Circulation 1970;41:899-912.

16. Chou T-C, Helm RA, Kaplan SA. Clinical vectorcardiography. New York: Grune and Stratton; 1974:59, 162.

17. Burch GE. An electrocardiographic syndrome characterized by absence of Q in leads I, V5 and V6. Am Heart J 1956;51:487-88.

18. Uhley HN. The fascicular blocks. Cardiovasc Clin 1973;5(3):87-97.

19. Castellanos A, Lemberg L. Re-evaluation of septal activation in the human heart. Am Heart J 1969;78:575-7.

20. Willems JL, Robles de Medina EO, Baernard R, et al. Criteria for intraventricular conduction disturbances and pre-excitation. J Am Coll Cardiol 1985;5:1261-75.

21. Lazzara R, El-Sharif N, Befeler B, Scherlag BJ. Regional refractoriness within the ventricular conduction system. An evaluation of the “gate” hypothesis. Circ Res 1976;39:254-62.

22. Iwamura N, Kodama I, Shimizu T, Hirata Y, Toyama J, Yamada K. Functional properties of the left septal Purkinje network in premature activation of the centricular conduction system. Am Heart J 1978;95:60-9.

23. Hoffman I, Mehta J, Hilsenrath J, Hamby RI. Anterior conduction delay: a possible cause for prominent anterior forces. J Electrocardiol 1976;9:15-21.

24. Kulbertus HE, de Laval-Rutten F, Casters P. Vectorcardiographic study of aberrant conduction. Anterior displacement of QRS: another form of intraventricular block. Br Heart J 1976;38:549-57.

25. Nakaya Y, Hiasa Y, Murayama Y, Ueda S, Nagao T, Niki T, Mori H, Takashima Y. Prominent anterior QRS forces as a manifestation of left septal fascicular block. J Electrocardiol 1978;11:39-46.

26. Reiffel JA and Bigger JT, Jr. Pure anterior conduction delay: a variant “fascicular" defect. J Electrocardiology 1978;11:315-19.

27. de Padua F, dos Reis D, Lopes VM, Pereira Miguel J, Lopes MG, da Silva TM, de Padua JP. Left median hemiblock –-- a chimera? Adv Cardiol 1978;21:242-8.

28. Gambetta M and Childers RW. Rate-dependent right precordial Q waves: “septal focal block”. Am J Cardiol 1973;32:196-201.

29. Piccolo E, Raviele A, Delise P, Dainese F, Pascotto P, Totaro G, Sartori F, D’Este D. The role of left ventricular conduction in the electrogenesis of left ventricular hypertrophy. An electrophysiologic study in man. Circulation 1979;59:1044-55.

30. Uhley HN and Rivkin LM. Electrocardiographic patterns following interruption of the main and peripheral branches of the canine left bundle of His. Am J Cardiol 1964;41-7.

31. Dabrowska B, Ruka M, Walczak E. The electrocardiographic diagnosis of left septal fascicular block. Eur J Cardiol 1978;6:347-57.

32. Kulbertus HE. Concept of left hemiblock revisited. A histopathological and experimental study. Adv Cardiol 1975;14:126-35.

33. Selvester RH, Wagner NB, Wagner GS. Ventricular excitation during percutaneous transluminal angioplasty of the left anterior descending coronary artery. Am J Cardiol 1988;62:1116-21.

34.. Uhley H. The fascicular blocks. Cardiovasc Clin 1973;5(3):87-97.

35. Bayés de Luna B. Clinical electrocardiography. 2nd ed. Armonk, NY: Futura Publishing Co.; 1998:92.

36. Mirvis DM. Electrocardiography. A physiologic approach. St. Louis: Mosby; 1993:291.

37. Scher AM, Young AC, Malmgren AL, Erickson RV. Activation of the interventricular septum. Circ Res 1953;3:56-64.

38. Erickson RV, Scher AM, Becker RA. Ventricular excitation in experimental bundle-branch block. Circ Res 1957;5:5-10.

39. Leighton RF, Ryan JM, Goodwin RS, Wooley CF, Weissler AM. Incomplete left bundle-branch block. The view from transseptal intraventricular leads. Circulation 1967;36:261-74.

40. Spach MS, Huang S-N, Armstrong SI, Canent RV, Jr. Demonstration of peripheral conduction system in human hearts. Circulation 1963;28:333-8.

41. Uhley H. Vector electrocardiography. Philadelphia: Lippincott Co.; 1962:17.

42. Kawai N, Sotobata I, Noda S, Okada M, Kondo T, Yokota M, Yamauchi K, Tsuzuki J. Correlation between the direction of the interventricular septum estimated with transmission computed tomography and the initial QRS vectors. J Electrocardiol 1984;17:401-8

43. Selvester RH, Wagner NB, Wagner GS. False-positive posterior myocardial infarct criteria during left anterior descending coronary angioplasty. J Electrocardiol 1988;21 (suppl):105-11.

44. Paparella N, Alboni P, Cappato R, Pirani R, Gruppillo P, Preziosi S, Battaglia R, Corio R, Occari G, Berti C, Sapigni T. Prominent anterior QRS forces: clinical, electrocardiographic and prospective study. J Electrocardiol 1987;20:233-40.

45. Reproduced from MacAlpin RN. In search of left septal fascicular block. Am Heart J 2002;144:948-56, with permision from Elsevier.

46. Sodi-Pallares D and Calder RM. New bases of electrocardiography. Lt. Louis: C.V. Mosby Co.; 1956: 282, 418, 489.

47. MacAlpin RN. Absent septal Q waves in otherwise normal electrocardiograms. A variant of normal? J Electrocardiol 2001;34:207-14.

48. Hoffman I. Clinical vectorcardiography in adults. Part I. Am Heart J 1980;100:239-54.

49. Silverberg SM. A quantitative study of the Frank vectorcardiogram. A comparison of younger and older normal populations. Am J Cardiol 1966;18:672-81.

50. Edenbrandt L, Jonson B, Lundh B, Pahlm O. Sex-and age-related normal limits for the QRS complex in vectorcardiography. Clin Physiol 1987;7:525-36.

51. Saito D, Ueeda M, Yamada N, Hina K, Watanabe H, Mima T, Yoshida H, Haraoka S, Tsuji T. The QRS complex of the standard 12-lead electrocardiogram in septal myocardial infarction. Jpn Circulation J 1988;52:1268-76.

52. MacAlpin RN. In search of left septal fascicular block. Am Heart J 2002;144:948-56.

53. Levy L, II, Hyman AL. Difficulties in the electrocardiographic diagnosis of myocardial infarction. Am Heart J 1950;39:243-62.

54. Tamura A, Kataoka H, Mikuriya Y. Electrocardiographic findings in patients with pure septal infarction. Br Heart J 1991;65:166-7.

55. Henein MY, O'Sullivan, CA, Ramzy IS, Segwart U, Gibson DG. Electromechanical left ventricular behavior after nonsurgical septal reduction in patients with hypertrophic obstructive cardiomyopathy. J Am Coll Cardiol 1999;34:1117-22.

56. Uhley H. Possible myocardial infarction suggested by the absence of expected Q waves. CVR&R 2001;22:223-5.

57. Cabrera CE and Monroy JR. Systolic and diastolic loading of the heart: II. Electrocardiographic data. Am Heart J 1952;43:669-86.

58. Piccolo E, Castellani A, Nava A. Vectorcardiogarphic patterns in systolic and diastolic overloading of the left ventricle. In: Rijlant P, editor. Proceedings of the XIIth International Colloquium Vectorcardiographicum. Brussels, August 4-7, 1971. Brussels: Presses Academiques Europeennes; 1972:428-30.

59. Beamer V, Amidi M, Scheuer J. Vectorcardiographic findings simulating myocardial infarction in aortic valve disease. J Electrocardiol 1970;3:71-6.

60. Gunnar RM, Pietras RJ, Blackaller J, Dadmun SE, Szanto PB, Tobin JR, Jr. Correlation of vectorcardiographic criteria for myocardial infarction with autopsy findings. Circulation 1967;35:158-71.

61. Horan LG, Flowers NC, Johnson JC. Significance of the diagnostic Q wave of myocardial infarction. Circulation 1971;43:428-36.

62. Hilsenrath J, Glassman E, Roberts G, Hamby RI, Hoffman I. Pitfalls in the prediction of coronary artery obstruction from ECG-VCG anterior infarct patterns. In: Hoffman I, Hamby RI, Glassman E, editors. Vectorcardiography 2. Proceedings of the XIth International Symposium on Vectorcardiography. New York, May 15-17. Amsterdam: North Holland Publishing Co.; 1971:362-7.

63. Hellerstedt M, Jonasson R, Orinius E. Electrocardiographic diagnosis of ventricular septal infarction. Acta Med Scand 1980;208:213-7.

64. Hassett MA, Williams RR, Wagner GS. Transient QRS changes simulating acute myocardial infarction. Circulation 1980;62:975-9.

65. Rebuzzi AG, Loperfido F, Beasucc LM. Transient Q waves followed by left anterior fascicular block during exercise. Br Heart J 1985;54:107-9.

66. DePasquale NP, Burch GE, Phillips JH. Electrocardiographic alterations associated with electrically “silent” areas of myocardium. Am Heart J 1964;68:697-709.

67. Rubin IL, Gross H, Vigliano EM. Transient abnormal Q waves during coronary insufficiency. Am Heart J 1966;71:254-9.

68. Bateman T, Gray R, Maddahi J, Rozanski A, Raymond M, Berman D. Transient appearance of Q waves in coronary disease during exercise electrocardiography: consideration of mechanisms and clinical importance. Am Heart J 1982;104:182-4.

69. Rosenbaum MB, Shabetai R, Peterson KL, O’Rourke RA. Nature of the conduction disturbance in selective coronary arteriography and left heart catheterization. Am J Cardiol 1972;30:334-7.

70. Kulbertus H, Collignon P, Humblet L. Vectorcardiographic study of the QRS loop in

patients with left anterior focal block. Am Heart J 1970;79:293-304.

71. Jacobson LB, La Follette L, Cohn K. An appraisal of the initial QRS forces in left anterior fascicular block. Am Heart J 1977;94:407-13.

72. Burchell HB, Tuna N. The interpretation of gross left axis deviation in the electrocardiogram. Eur J Cardiol 1979;10:259-77.

73. Rabkin SW, Mathewson FAL, Tate RB. Natural history of marked left axis deviation (left anterior hemiblock). Am J Cardiol 1979;43:605-11.

74. Peñaloza D, Gamboa R, Sime F. Experimental right bundle branch block in the normal human heart. Am J Cardiol 1961;8:767-79.

75. Scherlis L and Lee Y-C. Transient right bundle branch block. An electrocardiographic and vectorcardiographic study. Am J Cardiol 1963;11:173-86.

76. Cohen SI, Lau SH, Stein E, Young MW, Damato AN. Variations of aberrant ventricular conduction in man: evidence of isolated and combined block within the specialized conduction system. Circulation 1968;38:899-916.

77. Antonin B and Roje J. The vectorcardiogram in left anterior hemiblock with qrs or qRS patterns in right precordial leads. Adv Cardiol 1976;16:507-11.

78. Medrano GA, Brenes C, de Micheli A, Sodi-Pallares D. El bloqueo simultaneo de las subdivisiones anterior y posterior de la rama izquierda del haz de His (bloqueo bifascicular), y su asociación con bloqueo de la rama derecha (bloqueo trifascicular). Arch Inst Cardiol Mex 1970;40:752-70.

79. Xiao HB and Gibson DG. Absent septal q wave: a marker of the effects of abnormal activation pattern on left ventricular diastolic function. Br. Heart J 1994;72:45-51.

80. Henein MY Rosano GMC, Underwood R, Poole-Wilson PA. Relations between resting ventricular long axis function, the electrocardiogram, and myocardial perfusion imaging in syndrome X. Br. Heart J 1994;71:541-7.

81. Ono A, Mizuno H, Tahara Y, Ishikawa K. Phase imaging characterization of ventricular contraction in left anterior hemiblock. Jpn Circulation J 1991;55:473-80.

82. Cannom DS, Wyman MG, Goldreyer BN. Initial ventricular activation in left-sided intraventricular conduction defects. Circulation 1980;62:621-31.


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