Major determinant of the occurrence of pacing-induced cardiomyopathy in complete atrioventricular block: a multicentre, retrospective analysis over a 15-year period in South Korea

Abstract

ObjectivesThe predictors of pacing-induced cardiomyopathy (PICM) for complete atrioventricular block (CAVB) have not yet been defined. The aim of this study was to investigate the major determinant of the occurrence of PICM.SettingThis is a multicentre, retrospective analysis of CAVB from tertiary referral centres in Daejeon, South Korea.ParticipantsA cohort of 900 consecutive patients with an implanted pacemaker was collected from December 2001 to August 2015. Of these, a total of 130 patients with CAVB with pacing-dependent rhythm who underwent ECG and echocardiogram before and after implantation were analysed for the occurrence of PICM.Outcome measuresCox proportional hazards models evaluated the determinant of PICM by ECG, device parameters and echocardiogram over a mean of 4.5 years.ResultsPICM was observed in 16.1% (n=21) of all patients with CAVB (age, 64±11 years; male, 36.2%). The preimplant left ventricular (LV) ejection fraction (66%±9% vs 66%±8%) and non-apical pacing (40.4% vs 33.3%) were similar; however, the native QRS duration (124±34 ms vs 149±32 ms) and the paced QRS duration (pQRSd) (139±29 ms vs 167±28 ms) were significantly different between the two groups. The postimplant LV ejection fraction (61%±7% vs 31%±8%) was also significantly different at the end of follow-up. A pQRSd significantly correlated with PICM (HR 1.05, 95% CI 1.02 to 1.09, P=0.001). A pQRSd with a cut-off value of above 140 ms had a sensitivity of 95% while a pQRSd with a cut-off value of above 167 ms had a specificity of 90% for PICM.ConclusionIn patients with CAVB with pacing-dependent rhythm, regardless of the pacing site, the pQRSd is a major determinant of the occurrence of PICM.