Relation between QRS duration and atrial synchronicity in patients with systolic heart failure.

Objectives: The association of QRS duration (QRSd) with ventricular dyssynchrony is well-known in systolic heart failure (HF). However, there are no data regarding the relationship between QRSd and atrial dyssynchrony in patients with HF. We aimed to investigate the association of QRSd with intra-atrial and inter-atrial dyssynchrony in patients with systolic HF by using color tissue Doppler imaging (TDI).

Methods: The study consisted of 70 systolic HF patients and 35 healthy controls. According to QRSd, HF patients were categorized into 2 subgroups as narrow QRS (n = 35) and wide QRS (n = 35) groups. Time intervals between the onset of P-wave and the onset of A-wave on color TDI from the right atrium (P-RA), inter-atrial septum (P-IAS) and left atrium (P-LA) were measured. Atrial dyssynchrony was defined as differences between P-RA and P-IAS (RA dyssynchrony), between P-LA and P-IAS (LA dyssynchrony) and between P-RA and P-LA (inter-atrial dyssynchrony).

Results: In patients with either HF groups, we observed significant impairment in intra-atrial and inter-atrial synchronicity compared with the controls (P < 0.001). Moreover, LA, RA and inter-atrial synchrony were found to be significantly impaired in the wide QRS group compared to narrow QRS group. There was also a positive and strong correlation between atrial and ventricular dyssynchrony parameters. In stepwise multivariate analysis, QRSd was found to be the independent predictor of intra-atrial and inter-atrial dyssynchrony in systolic HF.

Conclusion: Among patients with systolic HF, prolonged QRSd is associated with impaired intra-atrial and inter-atrial synchrony. Atrial and ventricular dyssynchrony parameters were well-correlated with each other.