Ventricular premature depolarization QRS duration as a new marker of risk for the development of ventricular premature depolarization-induced cardiomyopathy.

BACKGROUND

Frequent ventricular premature depolarizations (VPDs) can cause cardiomyopathy (CMP). The mechanisms underlying its development remain unclear, with VPD burden being only a weak predictor of risk.

OBJECTIVE

To determine whether VPD QRS duration at the time of initial presentation could predict risk for the subsequent development of CMP in patients with normal left ventricular ejection fraction (LVEF).

METHODS

From consecutive patients referred for ablation between January 1, 2006, and April 2, 2013, with ≥10% VPDs on 24-hour Holter monitoring, we identified 45 patients with normal LVEF and an electrocardiogram of the targeted VPD, who were then followed for at least 6 months (median 14 months; interquartile range [IQR] 8-32 months) before intervention. We excluded patients with structural or genetic heart disease.

RESULTS

Of the 45 patients, 28 (62%) maintained normal LVEF and 17(38%) developed VPD-induced CMP. VPD burden was similar (26.5% [IQR 19.3%-39.5%] vs 26.0% [IQR 16.4%-41.0%]; P = 0.4) between the 2 groups. Patients who developed VPD-induced CMP had significantly longer VPD QRS duration (159 ms vs 142 ms; P < .001) and a longer sinus QRS duration (97 ms vs 89 ms; P = .04). A VPD QRS duration of ≥153 ms best predicted development of VPD CMP (82% sensitivity and 75% specificity). Longer VPD QRS duration and a non-outflow tract site of VPD origin were independent risk factors for left ventricular dysfunction after multivariate analysis.

CONCLUSION

VPD QRS duration longer than 153 ms and a non-outflow tract site of origin might be useful predictors of the subsequent development of VPD-induced CMP.