Association of Electrocardiographic Morphology of Exercise-Induced Ventricular Arrhythmia with Mortality

  1. Robert E. Eckart, DO;
  2. Michael E. Field, MD;
  3. Tomasz W. Hruczkowski, MD;
  4. Daniel E. Forman, MD;
  5. Sharmila Dorbala, MBBS;
  6. Marcelo F. Di Carli, MD;
  7. Christine E. Albert, MD, MPH;
  8. William H. Maisel, MD, MPH;
  9. Laurence M. Epstein, MD; and
  10. William G. Stevenson, MD
  1. From Brooke Army Medical Center, San Antonio, Texas; Brigham and Women's Hospital, Boston Veterans Administration Medical Center, and Beth Israel Deaconess Medical Center, Boston, Massachusetts; and the University of Alberta, Edmonton, Alberta, Canada.

    Abstract

    Background: The prognostic importance of exercise-induced ventricular arrhythmia (EIVA) may be confounded by the presence of lower-risk idiopathic right ventricular outflow tract arrhythmias with left bundle-branch block (LBBB) morphology.

    Objective: To determine whether right bundle-branch block (RBBB)–morphology EIVA was associated with increased mortality.

    Design: Retrospective cohort.

    Setting: Academic medical center.

    Patients: 585 unique patients with EIVA and 2340 patients without EIVA, matched by age, sex, and risk factor, who were referred for exercise testing in an academic medical center.

    Measurements: Deaths and ischemia and infarction found on perfusion scan.

    Results: During a mean follow-up of 24 months (SD, 13), 31 deaths occurred in the EIVA group compared with 43 deaths in the group without EIVA (5.3% vs. 1.8%; P < 0.001). Worse survival in patients with RBBB-morphology or multiple-morphology EIVA (6.9%) than in patients without EIVA caused this difference. Patients with LBBB-morphology EIVAs had a mortality rate (2.5%) similar to that of patients without EIVA (P = 0.93, log-rank test). Among patients without known atherosclerotic coronary artery disease, any RBBB-morphology EIVA was associated with death (hazard ratio, 2.73 [95% CI, 1.78 to 4.13]; P < 0.001), but LBBB-morphology EIVA was not (hazard ratio, 0.82 [CI, 0.18 to 2.04]; P = 0.72).

    Limitations: Not all LBBB-morphology EIVA can be dismissed, and not all RBBB-morphology EIVA is high risk. Further evaluation of patients for structural heart disease was clinically driven, not protocol-driven.

    Conclusion: Right bundle-branch block– or multiple-morphology EIVA is associated with increased mortality. Inclusion of patients with isolated LBBB-morphology EIVA, which often is idiopathic, may contribute to differences in the prognostic importance of EIVA in previous studies.

    Article and Author Information

    • Potential Financial Conflicts of Interest: Honoraria: L.M. Epstein (Medtronic, Boston Scientific, St. Jude). Grants received: L.M. Epstein (Medtronic, Boston Scientific, Biosense Webster).

    • Reproducible Research Statement: Study protocol: Available from Brigham and Women's Hospital Institutional Review Board, 75 Francis Street, Boston, MA 02115. Statistical code: Available from Dr. Eckart (e-mail, robert.eckart{at}us.army.mil). Data set: Certain portions of the analytic data set are available to approved individuals through written agreements with Dr. Eckart (e-mail, robert.eckart{at}us.army.mil).

    • Requests for Single Reprints: MAJ Robert E. Eckart, MC, USA, Arrhythmia Service (ATTN: MCHE-MDC), 3851 Roger Brooke Drive, Brooke Army Medical Center, San Antonio, TX 78234; e-mail, robert.eckart{at}us.army.mil.

    • Current Author Addresses: Dr. Eckart: Arrhythmia Service (ATTN: MCHE-MDC), 3851 Roger Brooke Drive, Brooke Army Medical Center, San Antonio, TX 78234.

    • Dr. Field: Cardiovascular Consultants of Maine, P.A., 96 Campus Drive, Suite 1, Scarborough, ME 04074.

    • Dr. Hruczkowski: Cardiology Arrhythmia Services, 2C1.16 Walter Mackenzie Centre, University of Alberta, Edmonton, Alberta T6G 2B7, Canada.

    • Drs. Forman, Dorbala, Di Carli, Albert, Epstein, and Stevenson: Cardiovascular Division, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115.

    • Dr. Maisel: Cardiovascular Division, Beth Israel Deaconess Medical Center, 185 Pilgrim Road, Baker 4, Boston, MA 02215.

    • Author Contributions: Conception and design: R.E. Eckart, M.E. Field, C.E. Albert, W.H. Maisel, L.M. Epsteìn, W.G. Stevenson.

    • Analysis and interpretation of the data: R.E. Eckart, M.E. Field, T.W. Hruczkowski, M.F. Di Carli, C.E. Albert, W.H. Maisel.

    • Drafting of the article: R.E. Eckart, M.E. Field, T.W. Hruczkowski, M.F. Di Carli, W.H. Maisel, L.M. Epsteìn.

    • Critical revision of the article for important intellectual content: R.E. Eckart, S. Dorbala, M.F. Di Carli, C.E. Albert, W.H. Maisel, L.M. Epsteìn, W.G. Stevenson.

    • Final approval of the article: R.E. Eckart, S. Dorbala, M.F. Di Carli, W.H. Maisel, L.M. Epsteìn, W.G. Stevenson.

    • Provision of study materials or patients: R.E. Eckart, S. Dorbala, M.F. Di Carli, L.M. Epsteìn.

    • Statistical expertise: R.E. Eckart, W.H. Maisel.

    • Obtaining of funding: R.E. Eckart.

    • Administrative, technical, or logistic support: R.E. Eckart.

    • Collection and assembly of data: R.E. Eckart, T.W. Hruczkowskì, M.F. Di Carli.

    Summary for Patients

    • Summaries for Patients:Type of Exercise-Induced Arrhythmia on Exercise Test and Risk for Death Ann Intern Med October 7, 2008 149:I-22
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    1. Ann Intern Med October 7, 2008 vol. 149 no. 7 451-460
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