Author + information
- Received February 2, 2017
- Revision received May 17, 2017
- Accepted June 9, 2017
- Published online December 18, 2017.
- Freddy Del-Carpio Munoz, MD, MSca,∗ (, )
- S. Michael Gharacholou, MD, MSca,
- Christopher G. Scott, MSb,
- Vuyisile T. Nkomo, MD, MPHa,
- Francisco Lopez-Jimenez, MDa,
- Yong-Mei Cha, MDa,
- Thomas M. Munger, MDa,
- Paul A. Friedman, MDa,c and
- Samuel J. Asirvatham, MDa,d
- aDivision of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
- bDivision of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota
- cDepartment of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
- dDivision of Pediatric Cardiology and Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
- ↵∗Address for correspondence:
Dr. Freddy Del-Carpio Munoz, Division of Cardiovascular Diseases, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905.
Objectives The goal of this study was to evaluate whether prolonged ventricular conduction (paced QRS) and repolarization (paced QTc) times observed during ventricular stimulation predict ventricular arrhythmic events and death.
Background Abnormal ventricular conduction and repolarization can predispose patients to ventricular arrhythmias.
Methods Consecutive patients with left ventricular dysfunction (ejection fraction <50%) undergoing electrophysiology studies from January 2002 until May 2014 were identified at Mayo Clinic (Rochester, Minnesota). Patients were followed up until December 2014 for occurrence of ventricular arrhythmias and death.
Results Among the 501 patients included (mean age 65 years; mean left ventricular ejection fraction 33.1%), longer paced ventricular conduction was associated with longer baseline QRS duration, longer QT interval, and lower ejection fraction. On multivariable analysis, longer paced QRS duration was associated with higher risk of ventricular arrhythmia (hazard ratio [HR]: 1.11 per 10-ms increase; 95% confidence interval [CI]: 1.07 to 1.16; p < 0.001) and all-cause death or arrhythmia (HR: 1.09; 95% CI: 1.09 to 1.13; p < 0.001). A paced QRS duration >190 ms was associated with a 3.6 times higher risk of ventricular arrhythmia (HR: 3.6; 95% CI: 2.35 to 5.53; p < 0.001) and a 2.1 times higher risk of death or arrhythmia (HR: 2.12; 95% CI: 1.53 to 2.95; p < 0.001), independent of left ventricular function or baseline QRS duration. Longer QTc interval during ventricular pacing was associated with a higher risk of ventricular arrhythmia (HR: 1.03 per 10-ms increase; 95% CI: 1.02 to 1.12; p < 0.001) independent of paced QRS duration.
Conclusions Longer paced QRS duration and paced QTc interval predict ventricular arrhythmias in patients with cardiomyopathy. Ventricular conduction and repolarization prolongation during right ventricular pacing can determine the risk of ventricular arrhythmias.
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors' institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received February 2, 2017.
- Revision received May 17, 2017.
- Accepted June 9, 2017.
- 2017 American College of Cardiology Foundation
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