QRS prolongation after premature stimulation is associated with polymorphic ventricular tachycardia in nonischemic cardiomyopathy: Results from the Leiden Nonischemic Cardiomyopathy Study

Sebastiaan R D Piers; Saïd F A Askar; Jeroen Venlet; Alexander F A A Androulakis; Gijsbert F L Kapel; Marta de Riva Silva; Jan J D H Jongbloed; J Peter van Tintelen; Martin J Schalij; Daniël A Pijnappels; Katja Zeppenfeld

doi:10.1016/j.hrthm.2015.12.021

QRS prolongation after premature stimulation is associated with polymorphic ventricular tachycardia in nonischemic cardiomyopathy: Results from the Leiden Nonischemic Cardiomyopathy Study

Heart Rhythm. 2016 Apr;13(4):860-9. doi: 10.1016/j.hrthm.2015.12.021. Epub 2015 Dec 14.

Affiliations

¹ Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
² Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
³ Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands,; Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
⁴ Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: K.Zeppenfeld@lumc.nl.

PMID: 26699238
DOI: 10.1016/j.hrthm.2015.12.021

Abstract

Background: Progressive activation delay after premature stimulation has been associated with ventricular fibrillation in nonischemic cardiomyopathy (NICM).

Objectives: The objectives of this study were (1) to investigate prolongation of the paced QRS duration (QRSd) after premature stimulation as a marker of activation delay in NICM, (2) to assess its relation to induced ventricular arrhythmias, and (3) to analyze its underlying substrate by late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) and endomyocardial biopsy.

Methods: Patients with NICM were prospectively enrolled in the Leiden Nonischemic Cardiomyopathy Study and underwent a comprehensive evaluation including LGE-CMR, electrophysiology study, and endomyocardial biopsy. Patients without structural heart disease served as controls for electrophysiology study.

Results: Forty patients with NICM were included (mean age 57 ± 14 years; 33 men [83%]; left ventricular ejection fraction 30% ± 13%). After the 400-ms drive train and progressively premature stimulation, the maximum increase in QRSd was larger in patients with NICM than in controls (35 ± 18 ms vs. 23 ± 12 ms; P = .005) and the coupling interval window with QRSd prolongation was wider (47 ± 23 ms vs. 31 ± 14 ms; P = .005). The maximum paced QRSd exceeded the ventricular effective refractory period, allowing for pacing before the offset of the QRS complex in 20 of 39 patients with NICM vs. 1 of 20 controls (P < .001). In patients with NICM, QRSd prolongation was associated with the inducibility of polymorphic ventricular tachycardia (16 of 39 patients) and was related to long, thick strands of fibrosis in biopsies, but not to focal enhancement on LGE-CMR.

Conclusion: QRSd is a simple parameter used to quantify activation delay after premature stimulation, and its prolongation is associated with the inducibility of polymorphic ventricular tachycardia and with the pattern of myocardial fibrosis in biopsies.

Keywords: Activation delay; Electrophysiology study; Nonischemic cardiomyopathy; Polymorphic ventricular tachycardia; Ventricular fibrillation.

Publication types

Clinical Trial

MeSH terms

Adolescent
Adult
Aged
Aged, 80 and over
Cardiomyopathies / complications
Cardiomyopathies / physiopathology*
Cardiomyopathies / therapy
Electric Stimulation / methods*
Electrocardiography*
Female
Follow-Up Studies
Heart Conduction System / physiopathology*
Heart Rate / physiology*
Humans
Male
Middle Aged
Prospective Studies
Tachycardia, Ventricular / etiology*
Tachycardia, Ventricular / physiopathology
Tachycardia, Ventricular / therapy
Time Factors
Treatment Outcome
Young Adult