Temporary transvenous pacing and femoral vein thrombosis.

The true incidence of thrombosis and pulmonary embolism in patients requiring temporary transvenous pacing via the femoral vein in unknown. Twenty-nine patients, mean age 66.2 years (range 38-79 years) who required temporary pacing were studied by bilateral contrast venography and perfusion lung scanning after removal of the pacing catheter. The patients were subdivided into two subgroups based on hemodynamic status. There was no statistical difference between the two groups with respect to mean age or the time the pacer catheter was in place and all patients were placed on low-dose heparin therapy. Ten patients (34%) had venographic evidence of thrombosis; six of them (60%) showed lung scan evidence of pulmonary emboli. The hemodynamically compromised group consisted of seven patients, six (85%) of whom had thrombosis; three of these six (50%) had pulmonary emboli. Of the 22 patients in the hemodynamically stable group, four (18%) had thrombosis and two of these (50%) had pulmonary emboli. Venous thrombosis, with subsequent pulmonary emboli, is a serious complication of temporary transvenous pacing using the femoral approach, despite the use of prophylactic low-dose heparin.