TY - JOUR
T1 - Natural history and clinical significance of isolated complete left bundle branch block without associated structural heart disease
AU - Ashraf, Hasan
AU - Agasthi, Pradyumna
AU - Siegel, Robert J.
AU - Pujari, Sai Harika
AU - Allam, Mohamed
AU - Shen, Win Kuang
AU - Srivathsan, Komandoor
AU - Sorajja, Dan
AU - Masry, Hicham El
AU - Freeman, William K.
AU - Mookadam, Farouk
AU - Mulpuru, Siva
AU - Arsanjani, Reza
N1 - Funding Information:
Acknowledgements: This work was supported by the Mayo Clinic Department of Cardiovascular Diseases which provided internal funding.
Publisher Copyright:
© 2021 Turkish Society of Cardiology. All rights reserved.
PY - 2021/3
Y1 - 2021/3
N2 - Objective: Left bundle branch block (LBBB), which is associated with underlying cardiac disease, is believed to play a role in the pathogenesis of cardiomyopathy through delays in interventricular conduction, leading to dyssynchrony. However, this has not been established in previous studies. It is unclear whether LBBB indicates clinically advanced cardiac disease or is an independent factor responsible for increased mortality and the development of heart failure. We investigated the natural history of isolated LBBB without any associated structural heart disease in order to determine its clinical significance.Methods: We performed a retrospective chart review on consecutive patients who fulfilled the 12-lead electrocardiographic (ECG) criteria for complete LBBB and had a normal echocardiogram with no evidence of structural heart disease and left or right ventricular systolic dysfunction within three months of the initial ECG between January 1, 2000 and December 31, 2009. We excluded patients with documented coronary artery disease (CAD) at any time, any structural heart disease, or cardiac devices. We evaluated the primary endpoints of mortality and incidence of cardiomyopathy, as well as any heart failure hospitalizations over a 1-and 10-year period.Results: We identified 2522 eligible patients. The mean follow-up duration was 8.43.2 years. The one-year mortality rate was 7.8%, with a 10-year mortality rate of 22.0%. The incidence of cardiomyopathy over one year was 3.2% and over 10 years was 9.1%. There was no significant difference in QRS duration between patients who were alive and those that were deceased at 10 years (141+/-18 vs. 141+/-17 ms; p=0.951) and patients with and without cardiomyopathy at 10 years (14217 vs. 14117 ms; p=0.532).Conclusion: Isolated LBBB occurring without structural heart disease, ventricular dysfunction, or CAD is associated with a low mortality rate and incidence of cardiomyopathy.
AB - Objective: Left bundle branch block (LBBB), which is associated with underlying cardiac disease, is believed to play a role in the pathogenesis of cardiomyopathy through delays in interventricular conduction, leading to dyssynchrony. However, this has not been established in previous studies. It is unclear whether LBBB indicates clinically advanced cardiac disease or is an independent factor responsible for increased mortality and the development of heart failure. We investigated the natural history of isolated LBBB without any associated structural heart disease in order to determine its clinical significance.Methods: We performed a retrospective chart review on consecutive patients who fulfilled the 12-lead electrocardiographic (ECG) criteria for complete LBBB and had a normal echocardiogram with no evidence of structural heart disease and left or right ventricular systolic dysfunction within three months of the initial ECG between January 1, 2000 and December 31, 2009. We excluded patients with documented coronary artery disease (CAD) at any time, any structural heart disease, or cardiac devices. We evaluated the primary endpoints of mortality and incidence of cardiomyopathy, as well as any heart failure hospitalizations over a 1-and 10-year period.Results: We identified 2522 eligible patients. The mean follow-up duration was 8.43.2 years. The one-year mortality rate was 7.8%, with a 10-year mortality rate of 22.0%. The incidence of cardiomyopathy over one year was 3.2% and over 10 years was 9.1%. There was no significant difference in QRS duration between patients who were alive and those that were deceased at 10 years (141+/-18 vs. 141+/-17 ms; p=0.951) and patients with and without cardiomyopathy at 10 years (14217 vs. 14117 ms; p=0.532).Conclusion: Isolated LBBB occurring without structural heart disease, ventricular dysfunction, or CAD is associated with a low mortality rate and incidence of cardiomyopathy.
KW - Cardiomyopathy
KW - Heart failure
KW - Left bundle branch block
KW - Mortality
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U2 - 10.14744/AnatolJCardiol.2020.10008
DO - 10.14744/AnatolJCardiol.2020.10008
M3 - Article
C2 - 33690131
AN - SCOPUS:85102834850
SN - 2149-2263
VL - 25
SP - 170
EP - 176
JO - Anatolian journal of cardiology
JF - Anatolian journal of cardiology
IS - 3
ER -