Aims: Phrenic nerve stimulation (PNS), which is often intolerable for the patient, is a known complication of resynchronization therapy. We describe a new, minimal invasive method for treating PNS.
Methods and results: Untreatable PNS was found in nine cardiac resynchronization therapy patients with distal coronary sinus (CS) lead position 6 +/- 6 (0.5-17) months after the implantation. Ablation catheter and Amplatz Left 2 type guiding catheter were introduced into the right atrium via the right femoral vein. Coronary sinus was cannulated with the Amplatz catheter, and on a normal guide wire, a coronary stent was introduced beside the lead into the side branch in seven cases or a bigger stent into the CS in two patients. The ablation catheter was looped around the CS lead in the atrium with bent tip and was drawn backward together with the CS electrode. New lead positions were evaluated with electrophysiological measurements, and the suitable position was stabilized with inflation of the stent. Pericardial effusion was not detected on post-operative echocardiography. After repositioning, suitable pacing parameters were registered (threshold: 1.6 +/- 1.1 V; 0.5 ms, impedance: 565 +/- 62 ohm). Phrenic nerve stimulation was not found with 7.5 V; 1.5 ms pacing. During follow-up (7.7 +/- 4.6 months), stable pacing threshold and impedance values were measured; transient and reprogrammable PNS was present in only one patient.
Conclusion: Coronary sinus electrode reposition using the femoral approach seems to be a safe and effective procedure, which means smaller burden for the patients compared with the established reposition operation. The technique can be used successfully if the CS lead is in a distal position.