Diagnosis of Abnormal Subclavian Venous Flow by Radionuclide Venography in Patients with Permanent Pacemaker.

In this study, we investigated the role of radionuclide venography in the diagnosis of abnormal subclavian venous flow due to the lead in patients (pts) with permanent pacemakers. The study was conducted with 53 frames in 52 asymptomatic pts (26 females, mean age 64.5 +/- 15; range 25-89 years). The mean time after implant was 67.6 +/- 47.5 months. Technetium 99m pertecnetate (250 MBq) was given to both antecubital veins simultaneously. The images were acquired in 0.25-second frames for 20 seconds. The pts were evaluated visually in terms of the activity flow through the subclavian veins bilaterally. The retrograde flow in the jugular vein, decrease in flow rate, and subtotal and total obstruction of the subclavian veins were accepted as abnormal venous flow patterns. In 17 pts with abnormal findings, 10 (58.8%) had retrograde flow in the jugular vein, 4 had (23.5%) decreased flow rate, 1 (5.8%) had subtotal and 2 (11.7%) total obstruction in the subclavian vein. The mean of the body diameter of the leads was significantly greater and the percentage of the silicone-insulated leads was higher (76% vs 52%) in the group with abnormal flow. No complication due to the procedure was seen. In conclusion, radionuclide venography, a noninvasive method, may be used easily and safely to show the venous flow abnormalities due to the lead in pts with permanent pacemakers. The abnormal subclavian venous flow was especially seen in pts who had larger leads.