Fragmented QRS and arrhythmic events in patients with implantable cardioverter-defibrillators

Abstract

Background: Patients with implantable cardioverter‑defibrillators (ICDs) may experience recurrent arrhythmic events (AE). Identification of these patients may help plan further therapy. Fragmented QRS (fQRS) was identified as a risk marker of AE in various populations but its predictive value in patients with ICD has not been established.

Aims: To examine whether fQRS is a risk marker of future AE in patients with ICD.

Methods: We retrospectively analyzed demographic, clinical, electrocardiographic (ECG), procedural, and follow‑up data of 367 consecutive patients who received ICD in a single tertiary center. A 12‑lead ECG recorded at the time of implantation was analyzed for the presence of fQRS. The analyzed primary endpoint was AE and total mortality was a secondary endpoint.

Results: During follow‑up lasting mean (SD) 34.5 (18) months, 146 patients (40%) had AE and total mortality was 18% (67 patients). Univariate analysis identified 7 parameters associated with AE of which 2—ICD implantation for secondary prevention (odds ratio [OR], 2.13; 95% CI, 1.13–4.025; P = 0.02) and fQRS in inferior ECG leads in patients with QRS duration of less than 120 ms (OR, 4.88; 95% CI, 1.18–20; P = 0.03)—remained significant in the multivariable analysis. Total mortality was associated with morbidity but not with fQRS.

Conclusions: Fragmented QRS in inferior ECG leads in patients with QRS duration < 120 ms is an independent parameter associated with AE in patients with ICD. Whether it could be helpful in deciding to perform early / prophylactic ablation in these patients needs to be prospectively studied