Incidence of strict versus nonstrict left bundle branch block after transcatheter aortic valve replacement.
BACKGROUND
Up to one-third of patients diagnosed with left bundle branch block (LBBB) by conventional electrocardiographic (ECG) criteria are misdiagnosed. Strict LBBB shows decreased left ventricular pumping efficiency compared with nonstrict LBBB. However, no previous study has evaluated the frequency of strict LBBB after transcatheter aortic valve replacement (TAVR). The aim of this study was to determine the incidence of developing strict versus nonstrict LBBB after TAVR and test the hypothesis that preprocedure QRS duration does not predict strict LBBB but predicts development of nonstrict LBBB.


METHODS
All patients receiving TAVR between 4/2011 and 2/2013 (n = 71) with no preexisting bundle branch block or permanent pacemaker were included. Twelve-lead ECGs were acquired preprocedure and both 1-day and 1-month postprocedure. All ECGs were classified as strict LBBB, nonstrict LBBB, or no LBBB.


RESULTS
Sixty-eight patients had ECGs eligible for final analysis. On postprocedure day 1, 25 (37%) of 68 patients developed strict LBBB, and 2 patients (3%) developed nonstrict LBBB. At 1-month follow-up, the 2 patients diagnosed with nonstrict LBBB had resolved to normal, and 5 (20%) of 25 patients with strict LBBB had resolved to normal. Preprocedure QRS duration did not predict strict LBBB (P = .51). Because of the low incidence of nonstrict LBBB, QRS duration as a predictor of nonstrict LBBB could not be tested.


CONCLUSIONS
Almost all patients who developed evidence of LBBB after TAVR met the new strict criteria, indicating probable procedural injury to the left bundle branch. Preprocedural QRS duration did not predict the development of strict LBBB.
Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden; Duke Clinical Research Institute, Durham, NC.
Frida
F
Sundh
Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden; Duke Clinical Research Institute, Durham, NC.
Jacob
J
Simlund
Division of Cardiology, Duke University Medical Center, Durham, NC.
John Kevin
JK
Harrison
Department of Surgery, Duke University Medical Center, Durham, NC.
G Chad
GC
Hughes
Division of Cardiology, Duke University Medical Center, Durham, NC; Department of Cardiology, University of North Carolina, Chapel Hill, NC.
John
J
Vavalle
Department of Health Services, University of Washington, Seattle, WA.
Charles
C
Maynard
Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD.
David G
DG
Strauss
Duke Clinical Research Institute, Durham, NC.
Galen S
GS
Wagner
Department of Clinical Physiology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden. Electronic address: martin.ugander@gmail.com.
Martin
M
Ugander
D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000601:surgery; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000453:epidemiology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D065467:Transcatheter Aortic Valve Replacement