Factors for development of left ventricular dysfunction during long-term right ventricular apical pacing / 대한내과학회지

ABSTRACT

BACKGROUND: It is known that prolonged QRS duration (QRSd) in a 12-lead ECG is associated with decreased left ventricular (LV) systolic function in patients with dilated cardiomyopathy. Development of LV systolic dysfunction and prolongation of paced QRSd are often observed in patients with permanent pacemakers (PPM). However, the significance of prolonged paced QRSd in patients with PPM is not determined. METHODS: We studied sixty-four patients (malefemale=2737, mean age=57.6+/-15.4 years) who had been on PPM (DDD 15, VDD 18, VVI 31) for more than one year (mean 68.2+/-44.0 months). LV function was normal before implantation of PPM. The 12-lead ECG and echocardiography were recorded prior to implantation, immediately after implantation and at the last follow-up. RESULTS: Paced QRSd did not significantly increase during the follow-up period. LVEF at the last follow-up (LVEF-FU) was significantly lower than that prior to implantation (59.3+/-11.5% vs. 64.9+/-10.1%, por=180 ms than in patients without (44.4+/-12.0% vs. 61.7+/-9.5%, p<0.001). In predicting LV systolic dysfunction with the paced QRSd (cut-off value 180 ms), sensitivity, specificity, positive and negative predictive values were 60.0%, 88.7%, 50.0% and 99.2%, respectively. The paced QRSd at the last follow-up was significantly correlated with paced QRSd immediately after implantation (r=0.542, p<0.01). CONCLUSION: LV systolic dysfunction after long-term right ventricular apical pacing may develop. Prolongation of paced QRSd 180 ms during follow-up may suggest development of LV systolic dysfunction. New technologies to minimize prolongation of paced QRSd should be investigated to prevent LV systolic dysfunction after permanent ventricular pacing.