1. Cardiac resynchronization therapy-induced acute shortening of QRS duration predicts long-term mortality only in patients with left bundle branch block
- Author
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Tomasz Sondej, Marek Jastrzębski, Danuta Czarnecka, Kamil Fijorek, Roksana Kisiel, Adrian Baranchuk, and Piotr Kukla
- Subjects
Male ,Bundle of His ,medicine.medical_specialty ,Time Factors ,medicine.medical_treatment ,Bundle-Branch Block ,Cardiac resynchronization therapy ,Action Potentials ,030204 cardiovascular system & hematology ,Risk Assessment ,Ventricular Function, Left ,Cardiac Resynchronization Therapy ,03 medical and health sciences ,QRS complex ,0302 clinical medicine ,Heart Rate ,Risk Factors ,Physiology (medical) ,Internal medicine ,Heart rate ,medicine ,Humans ,cardiovascular diseases ,030212 general & internal medicine ,Aged ,Retrospective Studies ,Aged, 80 and over ,Heart transplantation ,Left bundle branch block ,Surrogate endpoint ,business.industry ,Hazard ratio ,Middle Aged ,medicine.disease ,Treatment Outcome ,Heart failure ,Ventricular Function, Right ,cardiovascular system ,Cardiology ,Female ,Electrophysiologic Techniques, Cardiac ,Cardiology and Cardiovascular Medicine ,business ,circulatory and respiratory physiology - Abstract
Aims QRS narrowing with initiation of biventricular pacing might be an acute electrocardiographic indicator of correction of left bundle branch block (LBBB)-induced depolarization delay and asynchrony. However, its impact on prognosis remains controversial, especially in non-LBBB patients. Our goal was to evaluate the impact of QRS narrowing on long-term mortality and morbidity in a large cohort of patients undergoing cardiac resynchronization therapy (CRT) with different pre-implantation QRS types: LBBB, non-LBBB, and permanent right ventricular pacing. Methods and results This study included consecutive patients who underwent CRT device implantation. Study endpoints: death from any cause or urgent heart transplantation and death from any cause/urgent heart transplantation or hospital admission for heart failure. All pre- and post-implantation electrocardiograms were analysed using digital callipers, high-amplitude augmentation, 100 mm/s paper speed, and global QRS duration measurement method. A total of 552 CRT patients entered the survival analysis. During the 9 years observation period, 232 (42.0%) and 292 (52.9%) patients met primary and secondary endpoints, respectively. QRS narrowing predicted survival in the Kaplan-Meier analysis only in patients with LBBB. Multivariate Cox regression model showed that QRS narrowing was the major determinant of both study endpoints, with hazard ratios of 0.46 and 0.43, respectively. There was a strong relationship between mortality risk and shortening/widening of the QRS, albeit only in the LBBB group. Patients with non-LBBB morphologies had unfavourable prognosis similar to that in LBBB patients without QRS narrowing. Conclusion Acute QRS narrowing in patients with LBBB might be a desirable endpoint of CRT device implantation.
- Published
- 2018
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