DOI QR코드

DOI QR Code

Prognostic Implication of the QRS Axis and its Association with Myocardial Scarring in Patients with Left Bundle Branch Block

  • Park, Chan Soon (Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine) ;
  • Cha, Myung-jin (Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine) ;
  • Choi, Eue-Keun (Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine) ;
  • Oh, Seil (Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine)
  • 투고 : 2016.10.07
  • 심사 : 2016.12.20
  • 발행 : 2017.03.31

초록

Background and Objectives:Left bundle branch block (LBBB) with left axis deviation (LAD) has a worse prognosis than LBBB with a normal axis, and myocardial dysfunction has been suggested as a cause of left axis deviation. This study investigated the prognostic significance of the QRS axis in patients with LBBB and analyzed its relationship with the amount of myocardial scarring. Subjects and Methods: A total of 829 patients were diagnosed with LBBB at Seoul National University Hospital from October 2004 to June 2014. Of these, 314 who were asymptomatic and had no previous history of cardiac disease were included in the present study. Myocardial scarring was calculated using the Selvester QRS scoring system, and LAD was defined as a QRS axis between $-180^{\circ}$ and $-30^{\circ}$. Results: Of the total patients, 91 (29%) had LAD, and patients were followed for a median of 30 months. During follow-up, two patients were hospitalized for de novo heart failure, four had pacemaker implants, and 10 died. There was a significant inverse correlation between myocardial scar score and the QRS axis (r=-0.356, p<0.001). Patients with concomitant LAD had a higher rate of major cardiac adverse events compared with patients with a normal axis (5.5% vs. 1.3%, log-rank p=0.010); the prognostic value was attenuated in multivariable analysis (hazard ratio 4.117; 95% confidence interval 0.955-17.743; p=0.058). Conclusion: Concomitant LAD is an indicator of poor prognosis for patients with LBBB and may be associated with greater myocardial scarring.

키워드

참고문헌

  1. Haft JI, Herman MV, Gorlin R. Left bundle branch block: etiologic, hemodynamic, and ventriculographic considerations. Circulation 1971;43:279-87. https://doi.org/10.1161/01.CIR.43.2.279
  2. Yano K, Peskoe SM, Rhoads GG, Moore JO, Kagan A. Left axis deviation and left anterior hemiblock among 8,000 Japanese- American men. Am J Cardiol 1975;35:809-15. https://doi.org/10.1016/0002-9149(75)90116-2
  3. Patel PJ, Verdino RJ. Usefulness of QRS axis change to predict mortality in patients with left bundle branch block. Am J Cardiol 2013;112:390-4. https://doi.org/10.1016/j.amjcard.2013.03.045
  4. Dhingra RC, Amat-Y-Leon F, Wyndham C, Sridhar SS, Wu D, Rosen KM. Significance of left axis deviation in patients with chronic left bundle branch block. Am J Cardiol 1978;42:551-6. https://doi.org/10.1016/0002-9149(78)90622-7
  5. Lichstein E, Mahapatra R, Gupta PK, Chadda KD. Significance of complete left bundle branch block with left axis deviation. Am J Cardiol 1979;44:239-42. https://doi.org/10.1016/0002-9149(79)90311-4
  6. Parharidis G, Nouskas J, Efthimiadis G, et al. Complete left bundle branch block with left QRS axis deviation: defining its clinical importance. Acta Cardiol 1997;52:295-303.
  7. Wagner GS, Freye CJ, Palmeri ST, et al. Evaluation of a QRS scoring system for estimating myocardial infarct size. I. Specificity and observer agreement. Circulation 1982;65:342-7. https://doi.org/10.1161/01.CIR.65.2.342
  8. Strauss DG, Selvester RH. The QRS complex--a biomarker that "images" the heart: QRS scores to quantify myocardial scar in the presence of normal and abnormal ventricular conduction. J Electrocardiol 2009;42:85-96. https://doi.org/10.1016/j.jelectrocard.2008.07.011
  9. Lee SA, Cha MJ, Cho Y, Oh IY, Choi EK, Oh S. Paced QRS duration and myocardial scar amount: predictors of long-term outcome of right ventricular apical pacing. Heart Vessels 2016;31:1131-9. https://doi.org/10.1007/s00380-015-0707-8
  10. Strauss DG, Selvester RH, Lima JA, et al. ECG quantification of myocardial scar in cardiomyopathy patients with or without conduction defects: correlation with cardiac magnetic resonance and arrhythmogenesis. Circ Arrhythm Electrophysiol 2008;1:327-36. https://doi.org/10.1161/CIRCEP.108.798660
  11. Strauss DG, Cardoso S, Lima JA, Rochitte CE, Wu KC. ECG scar quantification correlates with cardiac magnetic resonance scar size and prognostic factors in Chagas' disease. Heart 2011;97:357-61. https://doi.org/10.1136/hrt.2010.210047
  12. Loring Z, Chelliah S, Selvester RH, Wagner G, Strauss DG. A detailed guide for quantification of myocardial scar with the Selvester QRS score in the presence of electrocardiogram confounders. J Electrocardiol 2011;44:544-54. https://doi.org/10.1016/j.jelectrocard.2011.06.008
  13. Strauss DG, Selvester RH, Wagner GS. Defining left bundle branch block in the era of cardiac resynchronization therapy. Am J Cardiol 2011;107:927-34. https://doi.org/10.1016/j.amjcard.2010.11.010
  14. Pryor R, Blount SG Jr. The clinical significance of true left axis deviation. Left intraventricular blocks. Am Heart J 1966;72:391-413. https://doi.org/10.1016/S0002-8703(66)80014-5
  15. Beach TB, Gracey JG, Peter RH, Grunenwald PW. Benign left bundle branch block. Ann Intern Med 1969;70:269-76. https://doi.org/10.7326/0003-4819-70-2-269
  16. Miller WL, Hodge DO, Hammill SC. Association of uncomplicated electrocardiographic conduction blocks with subsequent cardiac morbidity in a community-based population (Olmsted County, Minnesota). Am J Cardiol 2008;101:102-6. https://doi.org/10.1016/j.amjcard.2007.07.056
  17. McCrohon JA, Moon JC, Prasad SK, et al. Differentiation of heart failure related to dilated cardiomyopathy and coronary artery disease using gadolinium-enhanced cardiovascular magnetic resonance. Circulation 2003;108:54-9. https://doi.org/10.1161/01.CIR.0000078641.19365.4C
  18. Moon JC, McKenna WJ, McCrohon JA, Elliott PM, Smith GC, Pennell DJ. Toward clinical risk assessment in hypertrophic cardiomyopathy with gadolinium cardiovascular magnetic resonance. J Am Coll Cardiol 2003;41:1561-7. https://doi.org/10.1016/S0735-1097(03)00189-X
  19. Blyth KG, Groenning BA, Martin TN, et al. Contrast enhancedcardiovascular magnetic resonance imaging in patients with pulmonary hypertension. Eur Heart J 2005;26:1993-9. https://doi.org/10.1093/eurheartj/ehi328
  20. Davis JA. Anaerobic threshold: review of the concept and directions for future research. Med Sci Sports Exerc 1985;17:6-21.
  21. Gaultier C, Boule M, Thibert M, Leca F. Resting lung function in children after repair of tetralogy of Fallot. Chest 1986;89:561-7. https://doi.org/10.1378/chest.89.4.561

피인용 문헌

  1. Clinical Profile of the Patients with Newly Detected Left Bundle Branch Block in the Outpatient Department vol.8, pp.2, 2017, https://doi.org/10.4236/wjcd.2018.82014