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.