Left ventricular dysfunction after long-term right ventricular apical pacing in the young

Objectives The goal of this study was to assess long-term global left ventr icular (LV) function in patients paced from the right ventricular (RV) apex at a young age. Background Ventricular contraction asynchrony with short-term RV apical pac ing has been associated with reduced LV pump function and relaxation. The l ong-term effect of RV apical pacing on global LV function in the young rema ins unknown. Methods Twenty-four patients with normal segmental anatomy paced from the R V apex (follow-up 1 to 19 years) underwent noninvasive assessment of global LV function with automated border detection echocardiography-derived fract ional area of change (FAC), coupled with the Doppler index of myocardial pe rformance (MPI). Data were analyzed from 24 RV-paced patients (mean follow- up 9.5 years, age 19 years, body surface area [BSA] 1.6 m(2), QRS duration 140 ms) and compared with 33 age- and BSA-matched control subjects (age 16. 4 years, BSA 1.6 m(2)). Multiple linear regression analysis was performed t o identify patient variables that can affect these indexes of LV function. Results Assessment of LV function (median follow-up 10 years) in 24 paced p atients demonstrated impaired area- and Doppler how-derived indexes of LV s ystolic and diastolic function, compared with those indexes of control subj ects (FAC: 52% vs. 60%, p < 0.01; MPI: 0.46 vs. 0.34, p < 0.01). Paced QRS interval and age were found to significantly influence global LV contractio n in these patients (R-2 = 0.4, p < 0.05). Conclusions In the presence of impaired LV function with long-term RV apica l pacing, alternative sites of ventricular pacing that simulate normal bive ntricular electrical activation should be explored to preserve function in pediatric patients in need of long-term pacing. (J Am Coll Cardiol 2001;37: 2093-100) (C) 2001 by the American College of Cardiology.