Surface electrogram-guided left ventricular lead placement improves response to cardiac resynchronization therapy

Özet

Objective: Failure to select the optimal left ventricular (LV) segment for lead implantation is one of the most important causes of unresponsivenessto the cardiac resynchronization therapy (CRT). In our study, we aimed to investigate the echocardiographic and clinical benefits of LV leadimplantation guided by an intraoperative 12-lead surface electrocardiogram (ECG) in patients with multiple target veins.Methods: We included 80 [42 (62.5%) male] heart failure patients who successfully underwent CRT defibrillator (CRT-D) implantation. Patientswere divided into two groups. In group 1, LV lead was positioned at the site with the shortest biventricular-paced (BiV-paced) QRS duration(QRSd), as intraprocedurally measured using surface ECG. In group 2 (control), we included patients who underwent the standard unguided CRT.ECG, echocardiogram, and functional status were evaluated before and 6 months after CRT implantation in all patients.Results: In group 1, BiV-paced QRSd measurements were successfully performed in 112 of 120 coronary sinus branches during CRT and an LVlead was successfully placed at the optimal site in all patients. Compared with group 2, group 1 had a significantly higher rate (85% vs. 50%,p=0.02) of response (>15% reduction in LV end-systolic volume) to CRT as well as a shorter QRSd (p<0.001) and a greater QRS shortening (∆QRS)associated with CRT compared with baseline (p<0.001). The mean New York Heart Association functional class was significantly improved inboth groups, and no significant differences were found in clinical response to CRT (85% vs. 70%, p=0.181).Conclusion: Surface ECG can be used to guide LV lead placement in patients with multiple target veins for improving response to CRT. Thus, it is a safe, feasible, and economic approach for CRT-D implantation.