Long-term performance of single-pass physiological pacing.

BACKGROUND: Single-pass physiological pacing has several advantages over dual-lead physiological pacing. The present study evaluated the long-term performance of single-pass pacing using the overlapping biphasic impulse stimulation technique. METHODS AND RESULTS: A total of 30 patients with single-pass VDD pacing and 8 patients with single-pass DDDC pacing were followed up for 1 year by basal and magnet electrocardiograms and real-time telemetry. All the patients showed satisfactory atrial sensing and pacing capture threshold. The atrial sensing thresholds at implant and at 1 month, 3 months, 6 months and 12 months of follow-up were 2.5+/-0.67 mV, 1.6+/-0.6 mV, 1.1+/-0.5 mV, 1.0+/-0.5 mV and 1.0+/-0.04 mV, respectively. The corresponding values for atrial pacing threshold at a pulse wave of 0.5 ms were 2.5+/-1.0 V, 4.4+/-0.9 V, 3.8+/-1.2 V, 3.6+/-1.4 V and 3.8+/-1.4 V. Of the patients with DDDC pacing, 88% showed stable pacing capture in the supine position, 75% in the upright position and 62% in both positions. Diaphragmatic contraction was seen in 25% of cases with DDDC pacing. No such event was seen in patients with VDD pacing. CONCLUSIONS: Single-pass pacing is safe, technically easy and cheap as compared to dual-lead systems. However, it would be prudent to recommend DDDC pacing in patients who require predominantly VDD pacing and only occasionally atrial pacing, as the latter showed a low percentage of stable atrial pacing capture in both upright and supine positions as well as a significant percentage of diaphragmatic contraction.

Unilateral inter-nuclear ophthalmoplegia in systemic lupus erythematosus.

We report a case of a 14 year old girl with SLE who developed neurological involvement in the form of posterior internuclear ophthalmoplegia (pINO). An MRI showed lesion involving pons which corroborated with the pINO.

Venous obstruction after permanent pacing.

In a 10-year prospective study of 6,256 patients (5,812 males, 444 females) with permanent pacemaker, 25 had presented with features of venous obstruction such as pain, swelling or dilated superficial veins of face, upper limb(s) or upper chest wall without congestive heart failure. When subjected to contrast venography, 22 (0.35%) of the cases demonstrated subclavian and/or superior vena cava thrombotic/fibrotic obstruction. Each patient had non-progressive dilated veins over upper chest wall which developed after an average period of six months of implantation and none had embolic events or cephalad propagation of thrombus. Nine patients had subclavian, eight superior vena cava and five had both the vein obstructions. Seven patients of venous obstruction were treated with heparin followed by oral anticoagulants and three patients with oral anticoagulants alone. Three of seven patients got relief of obstruction with combined therapy group (heparin followed by oral anticoagulants) only. Two patients with superior vena cava obstruction needed epicardial pacing during subsequent lead revision. Therefore, before revision of permanent pacemaker leads in patients with signs of venous obstruction, venography can be useful to assess the obstruction and to determine the route of new lead insertion.