Impact on right ventricular performance in patients undergoing permanent pacemaker implantation: Left bundle branch pacing versus right ventricular septum pacing

Figures

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  Figure 1. Representative examples of right ventricular parameters analysis and QRSd in both groups. Paced QRS duration of LBBP (B, left) was slightly wider than that of that in native‐conduction mode (A, left). While QRSd of RVSP (D, left) mode was obvious wider than that in native‐conduction mode (C, left). As for right ventricular parameters analysis, superimposed end‐diastolic (ED; green) and end‐systolic (ES; yellow) endocardial borders for the right ventricle, and speckle‐tracking analysis of the RV is performed in the RV‐focused apical four‐chamber view, from which dimension, function, global and segmental longitudinal strain were derived. A comprehensive array of data can be visualized. Similar RV‐GLS and time of peak strain in the RV segments was relatively concentrated in native‐conduction (A, right) and LBBP capture modes (B, right) by speckle‐tracking analysis of the RV in a patient with SSS. Poorer RV‐GLS and time of peak strain in the RV segments was discrete showed in RVSP capture mode (D, right) compared with native‐conduction mode (C, right) in another patient with SSS. EDA, right ventricular end diastolic area; EDDmid, right ventricular end diastolic diameter‐mid; EDL,…

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  Figure 2. Comparison of RV and interventricular mechanical synchrony between LBBP and RVSP groups. Smaller means of IVMD during LBBP indicates mechanical contraction of LV earlier than RV (A). LBBP maintained a similar IVSA to native conduction, and was significantly better than that of RVSP (B). There were no significant differences on RV Ts‐6 (C), or RV‐SD4 (D) between pacing mode or native conduction mode in both groups. RV Ts‐6, the standard deviation of the time from QRS onset to peak systolic velocity in six right ventricular lateral wall and interventricular septal segments. IVMD, interventricular mechanical delay; IVSA, the time difference from the onset of the QRS complex to the peak systolic velocities between left ventricle and right ventricle; LBBP, left bundle branch pacing; NCM, native conduction mode; PCM, paced capture mode; RVSP, right ventricular septum pacing; RV‐SD4, the standard deviation of the times to peak‐systolic strain for the four mid‐basal right ventricular segments corrected to the R‐R interval between two QRS complexes.

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  Figure 3. Comparison of RV function between LBBP and RVSP groups. RVSP manifested significant worsening in RV‐FAC (A) and RV‐GLS (B–D) compared with intrinsic conduction. On the contrary, LBBP is similar to native conduction in all indexes relating to RV hemodynamic effect. EndoGLS, endocardial global longitudinal strain; FreeWallSt, strain of right ventricular free wall; LBBP, left bundle branch pacing; NCM, native conduction mode; PCM, paced capture mode; RVSP, right ventricular septum pacing; RV‐FAC, fractional area change; MyoGLS, myocardial global longitudinal strain.

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  Figure 4. Comparison of TR and RV function between LBBP subgroups of different pacing sites. AIVS, anterior interventricular septum; E‐T distance, the distance from the electrode fixation site to the tricuspid annulus; EndoGLS, endocardial global longitudinal strain; NCM, native conduction mode; PIVS, posterior interventricular septum; PCM, paced capture mode; RAA, right atrial area; RV‐FAC, fractional area change; TR, tricuspid regurgitation.