Phrenic nerve stimulation occurred in 12.9% of patients and was significantly more frequent at middle-lateral/posterior and apical LV sites compared to other sites (13.8% vs 6.7%; P=0.01).
Cohort (n=1,307)
Yes
Does left ventricular lead type and placement site affect the risk of phrenic nerve stimulation in patients undergoing cardiac resynchronization therapy?
Phrenic nerve stimulation occurs in approximately 13% of CRT patients and is significantly more common with lateral and apical LV lead placements, though most cases can be managed with electrical reprogramming.
Absolute Event Rate: 13.8% vs 6.7%
p-value: p=0.01
AIMS: Unwanted phrenic nerve stimulation (PNS) has been reported in ∼1 in 4 patients undergoing left ventricular (LV) pacing. The occurrence of PNS over mid-term follow-up and the significance of PNS are less certain. METHODS AND RESULTS: Data from 1307 patients enrolled in pre-market studies of LV leads manufactured by Medtronic (models 4193 and 4195 unipolar, 4194, 4196, 4296, and 4396 bipolar) were pooled. Left ventricular lead location was recorded at implant using a common classification scheme. Phrenic nerve stimulation symptoms were either spontaneously reported or identified at scheduled follow-up visits. A PNS-related complication was defined as PNS resulting in invasive intervention or the termination of LV pacing. Average follow-up was 14.9 months (range 0.0-46.6). Phrenic nerve stimulation symptoms occurred in 169 patients (12.9%). Phrenic nerve stimulation-related complications occurred in 21 of 1307 patients (1.6%); 16 of 738 (2.2%) in the unipolar lead studies, and 5 of 569 (0.9%) in the bipolar lead studies (P = 0.08). Phrenic nerve stimulation was more frequent at middle-lateral/posterior, and apical LV sites (139/1010) vs. basal-posterior/lateral/anterior, and middle-anterior sites (20/297; P= 0.01). As compared with an anterior LV lead position, a lateral LV pacing site was associated with over a four-fold higher risk of PNS (P= 0.005) and an apical LV pacing site was associated with over six-fold higher risk of PNS (P= 0.001). CONCLUSION: Phrenic nerve stimulation occurred in 13% of patients undergoing LV lead placement and was more common at mid-lateral/posterior, and LV apical sites. Most cases (123/139; 88%) of PNS were mitigated via electrical reprogramming, without the need for invasive intervention.
Biffi et al. (Sun,) conducted a cohort in Cardiac resynchronization therapy (n=1,307). Middle-lateral/posterior and apical left ventricular lead placement vs. Basal-posterior/lateral/anterior and middle-anterior left ventricular lead placement was evaluated on Phrenic nerve stimulation symptoms (p=0.01). Phrenic nerve stimulation occurred in 12.9% of patients and was significantly more frequent at middle-lateral/posterior and apical LV sites compared to other sites (13.8% vs 6.7%; P=0.01).