How can we identify the optimal pacing site in the right ventricular septum? A simplified method applicable during the standard implanting procedure.

Aims: A short paced (p) QRS duration (d) can be a marker for selecting the most appropriate RV pacing site. Although this could be achieved by continual 12-Lead ECG monitoring, such a technique is not applicable during pacemaker (PM) implantation. The purpose of this study was to validate a method for identifying the optimal site for RV septum pacing using simple markers derived from few real-time ECG leads and fluoroscopy (F).

Methods And Results: An overall of 304 measurements of pQRSd in different RV sites was performed in 102 patients undergoing PM implant. In accordance with F position the lead placement was classified high, medium, and low septum. Paced electrocardiographic/fluoroscopic parameters (q-wave/negative QRS in lead I, notching in limb leads, R/S wave in lead II, QRS precordial leads transition, and F septal segments pacing site) were analyzed to predict short pQRSd (≤ 160 ms). Logistic regression analysis showed that pQRSd > 160 ms was predicted by presence of pQRS notching in limb leads (OR = 3.24, p < 0.001), and with negative amplitude of QRS in lead II (OR = 2.53, p = 0.03). Short pQRSd (≤ 160 ms) was observed with mid F position (OR = 0.31, p < 0.001) and with the presence of a q-wave/negative QRS in lead I.

Conclusion: In RV septum pacing, simple QRS markers of few limb leads (lead I/II) added to F position are usefull to identifying the optimal site to place the RV lead.