Transvenous temporary cardiac pacing, with catheters frequently used along the femoral route, is useful to relieve difficult bradyarrhythmias and some tachyarrhythmias. Unfortunately, up to one third of patients receiving transfemoral pacing develop asymptomatic deep venous thrombosis (DVT). At present, there are no recommendations for thrombus prophylaxis in these patients, and heparin efficacy in this specific condition has not been studied. Sanders and associates used a prospective study to quantitate the risk of lower limb DVT in patients requiring temporary transfemoral pacing and to evaluate the use of heparin in thrombus prevention.

Forty-six consecutive patients who underwent transvenous femoral pacing and had no contraindication to heparin therapy were given unfractionated heparin during the time the catheter was in place. They received prophylactic heparin (5,000 IU subcutaneously every 12 hours) or therapeutic heparin (5,000 IU intravenously as a bolus dose followed by an adjusted infusion to maintain an activated partial thromboplastin time between 50 and 80 seconds). Patients were evaluated daily for clinical features of DVT. Duplex venous imaging was performed on both lower limbs of all patients within 24 hours of removal of the temporary pacemaker.

Eighteen patients (39 percent) had ultrasound evidence of lower limb DVT on the side used for placement of the pacemaker. All cases of DVT were asymptomatic. No evidence of thrombus was noted in the contralateral lower limb. DVT incidence was significantly reduced among patients using therapeutic levels of intravenous heparin. No heparin-related complications were noted in this study.

The authors conclude that DVT is a common complication of femoral pacing, and that its incidence can be reduced by up to 85 percent with the use of therapeutic intravenous heparin.