Clinical significance of fragmented QRS in isolated hypertension: Associations with ventricular arrhythmia burden and autonomic dysfunction.

BACKGROUND

Fragmented QRS (fQRS) complexes have been associated with myocardial conduction abnormalities and arrhythmic risk in various cardiac conditions. However, their clinical significance in patients with isolated hypertension, particularly in relation to ventricular arrhythmia burden and autonomic dysfunction, remains incompletely understood. This study aimed to investigate the association between fQRS, ventricular arrhythmia burden, left ventricular geometry, and cardiac autonomic function in these patients.

METHODS

This retrospective observational study included 229 patients with isolated hypertension who underwent 24-h rhythm Holter monitoring and ambulatory blood pressure monitoring. Patients were classified according to the presence of fQRS on standard 12‑lead electrocardiography. Ventricular arrhythmias were evaluated using Holter recordings and classified according to the Lown classification system. Cardiac autonomic function was assessed using heart rate variability (HRV) and heart rate turbulence (HRT) parameters. Echocardiographic evaluation was performed to assess left ventricular mass and geometry. Comparisons were made between patients with and without fQRS, and multivariable logistic regression analysis was used to identify independent predictors of higher arrhythmia burden.

RESULTS

fQRS was present in 101 patients (44.1%) who demonstrated significantly higher ventricular and atrial ectopic burden and were more frequently classified into higher Lown arrhythmia classes compared with those without fQRS (p < 0.001). Echocardiographic assessment revealed greater left ventricular mass index and a higher prevalence of concentric hypertrophy in patients with fQRS. Standard HRV parameters (SDNN and RMSSD) as well as the variability index (%), were significantly lower in the fQRS group, and impaired HRT was observed exclusively among these patients. Non-dipper heart rate pattern was also significantly more frequent in patients with fQRS. In multivariable analysis, lower SDNN values, the presence of fQRS, concentric hypertrophy, and non-dipper heart rate pattern emerged as independent predictors of higher Lown classification.

CONCLUSIONS

In patients with isolated hypertension, fQRS is associated with increased ventricular arrhythmia burden, adverse left ventricular remodeling, and objective markers of autonomic dysfunction.