Usefulness of Fragmented QRS Complexes in Patients With Congenital Heart Disease to Predict Ventricular Tachyarrhythmias.

Fragmented QRS complexes (fQRS) on 12-lead electrocardiogram are known predictors of ventricular tachyarrhythmia (VTA) in patients with coronary artery disease. There is limited knowledge of the clinical implications of fQRS in patients with congenital heart defects (CHD). Aims of this study were to examine (1) the occurrence of fQRS in patients with various types of CHD and (2) whether fQRS is associated with development of VTA. This study was designed as retrospective case-control study. Patients with CHD with VTA were included and matched with control patients of the same age, gender, and CHD type. Clinical data and fQRS were analyzed and compared. The initial VTA episode developed in 139 patients with CHD at a mean age of 39 ± 14 years. Compared with controls (n = 219, age 38 ± 13 years), QRS duration was longer in patients with VTA (110 vs 100 ms; p <0.01). Furthermore, fQRS was more frequently observed in patients with VTA in the last electrocardiogram before VTA (n = 73 [53%] vs n = 67 [31%]; p <0.001), especially in patients with sustained VTA (64%). Multiple conditional logistic regression demonstrated more fQRS (odds ratio [OR] 2.9, 95% confidence interval [CI] 1.5 to 5.8; p = 0.002), nonsystemic ventricular dysfunction (OR 5.1, 95% CI 2.1 to 12.4; p <0.001), and more prolonged QRS complexes (OR 2.8, 95% CI 1.3 to 6.2; p = 0.011) in patients with VTA. Therefore, the presence of fQRS on electrocardiogram may be a useful tool in daily clinical practice to identify patients at risk for developing VTA in patients with CHD, in addition to known predictors of VTA.