Feasibility of EASI system as alternative to EP recording system in left bundle branch area pacing procedures

Background and Aims

Standard 12-lead ECG is essential for assessing depolarization intervals and confirming conduction system capture during pacing procedures [1]. However, its setup may be cumbersome and interfere with fluoroscopic visualization. The EASI system, proposed by Dower [2], offers a simplified alternative, deriving a 12-lead ECG from only 4 electrodes. This system has already been evaluated in His Bundle Pacing (HBP) procedures, demonstrating its feasibility and potential clinical utility. [3]

This study aims to evaluate the reliability and clinical utility of EASI-derived ECG in Left Bundle Branch Area Pacing (LBBAP) procedures, particularly in identifying conduction system capture and differentiating pacing types.

Methods

This prospective study enrolled 5 patients with standard indications for pacemaker implantation. In all cases, LBBAP was attempted. Lead placement was guided by EHRA criteria, [1] including a ‘W’ pattern with a notch in V1 and discordant QRS morphology in leads II and III. The V6 R-wave peak time (V6RWPT), V6-V1 interpeak interval, and QRS transition were evaluated to confirm LBBAP. To this end, we employed an EASI system (CardioSecur Pace), which provides a 12-lead ECG along with a 3D map of electrical activation derived from only four electrodes. No EP recording systems were employed during the procedures.

Results

The median age of patients included in the study was 78 years, the median values of baseline QRS duration (QRSd) was 156ms, and the median PR interval was 184ms. LBBA pacing was successfully performed in all cases. The target position was easily determined according to ECG criteria as well as LBBAP criteria were confirmed using the CardioSecur system. All measures were performed using digital calipers available on the system. At the end of the procedures, the median paced QRSd was 128ms, while V6RWPT and V6-V1 interpeak interval were 72ms and 48ms (Table 1), respectively. The 3D map was exploited during pacing to provide a qualitative and rapid visual confirmation of ECG pattern changes during lead screwing and to observe ventricles activation with the final device programming (Figure 1). Impedance and current of injury (COI) were monitored using programmer analyzing system (PSA) as per current clinical practice.

Conclusions

In our experience, the EASI system has proven to be both feasible and efficient. The visualization of the 12-lead ECG was reliable and consistently aligned with lead positions and the final ECG acquired using a traditional ECG monitor. Additionally, the 3D map of electrical activation may contribute to improved outcomes during procedures, particularly in optimizing device programming. This innovative solution shows promise as a potential alternative to the EP recording system during LBBAP procedures, however, further evaluation is required to confirm its validity and effectiveness.LBBAP Criteria with EASI systemPatient characteristics