Electrocardiographic Predictors of Complete Heart Block During Right Ventricular Lead Implantation in Patients Who Underwent Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy (CRT) device procedures have their own complications in addition to the complications associated with standard pacemaker implantations. This study aimed to analyze the predictors of the right bundle branch injury resulting in complete heart block (CHB) during right ventricular (RV) lead implantation in patients who underwent CRT with defibrillator. We conducted an observational study of consecutive 790 patients who underwent CRT with defibrillator device implantation at our institution from 2010 to 2022. Relevant clinical information and complete data regarding the echocardiographic data, implantation procedure, and clinical follow-up were collected into a computerized database. A total of 29 patients (3.7%) had CHB during RV lead implantation. In multivariate analysis, left axis deviation (odds ratio [OR] 2.408, 95% confidence interval [CI] 1.025 to 5.658, p = 0.044), QRS width (OR 1.022, 95% CI 1.001 to 1.043, p = 0.035) and QRS alternans (OR 4.214, 95% CI 1.788 to 9.930, p = 0.001) were found independently related to right bundle branch injury resulting in CHB development during RV lead implantation. In conclusion, left axis deviation, QRS width, and QRS alternans were associated with a higher rate of CHB, and these findings provide insight into optimal and safe CRT device implantation strategies based on preprocedural characteristics.