Frequency of cardiac conduction disturbances after balloon aortic valvuloplasty

Disturbances in atrioventricular conduction are well-recognized complications of transcatheter aortic valve replacement. Percutaneous balloon aortic valvuloplasty (BAV) is a requisite step in transcatheter aortic valve replacement; however, the contribution of the BAV to atrioventricular conduction disturbances has not been elucidated. The present analysis was undertaken to ascertain the incidence and type of electrocardiographic changes associated with BAV and to consider the role of BAV in the conduction abnormalities after transcatheter aortic valve replacement. In 271 consecutive patients with symptomatic, severe aortic stenosis undergoing BAV, a standard 12-lead electrocardiogram was obtained before and serially after the procedure. Each was examined by experienced electrocardiographers. The cohort was divided into 2 groups with regard to the post-BAV appearance of conduction disturbances. The clinical and procedural characteristics of patients with these disturbances were compared to those in whom no conduction disturbance appeared. After BAV, 23 patients (8.5%) met the study definition of "new conduction defect": 4 patients (1.5%) required permanent pacemaker implantation for advanced atrioventricular block. New left bundle branch block appeared in 9 (3.3%) and left anterior hemiblock in 7 (2.6%). New right bundle branch block appeared in 2 and left posterior hemiblock in 1. No significant difference was found in the clinical or procedural characteristics. The ratio of the balloon size to the left ventricular outflow tract diameter was 1.21 ± 1.6 in those with new conduction defects and 1.15 ± 0.12 (p = 0.032) in those without. In conclusion, BAV is associated with a low incidence of cardiac conduction disturbances and a requirement for permanent ventricular pacing. The size of the valvuloplasty balloon should be carefully selected to avoid oversizing, which can lead to the development of postprocedure conduction disturbances.