Inadvertent permanent ventricular pacing from the coronary vein: an electrocardiographic, roentgenographic, and echocardiographic assessment.

The incidence of inadvertent permanent ventricular pacing from the coronary vein is not known. In a retrospective analysis of 69 patients in whom transvenous pacemakers were implanted between 1979 and 1986, 12 patients were discovered to have right bundle-branch block pattern to the paced complexes on electrocardiogram. In this group, three patients were considered to have inadvertent placement of pacing lead in the coronary vein by two-dimensional echocardiographic criteria. No complications were noted in follow-up of 2-79 months. Monitoring of surface electrocardiogram, frontal and lateral fluoroscopy, and pacing threshold and sensing parameters (during implantation of pacemaker) were found to offer no absolute protection against malplacement of the lead. Placement of the lead into the lung field via the main pulmonary artery and then withdrawing with eventual positioning into the right ventricular apex will avoid malposition into the coronary vein. Two-dimensional echocardiography is useful for the diagnosis of pacing lead malplacement and should be performed in any patient with right bundle-branch block pattern in the surface electrocardiogram following pacemaker implantation.