Relationship Between Electrical Parameters and Cardiac Synchrony in Patients Underwent Left Bundle Branch Area Pacing

Figures

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  FIGURE 1. Demonstration of lead positions in radiography under RAO 30° in different subgroups. (a) Subgroups are divided according to the presence of LBB potential and PVI. Orange dots: PVI > 20 ms; blue dots: PVI < 20 ms; yellow circle: negative for P potential. (b) Subgroups divided according to the QRS axis. Orange triangle: NEA; blue triangle: LAD; yellow triangle: RAD. (c) Subgroups are divided according to Stim‐LVAT. Orange dots: Stim‐LVAT < 60 ms; blue dots: Stim‐LVAT 60–70 ms; yellow dots: Stim‐LVAT > 70 ms. LAD indicates left axis deviation; LBB, left bundle branch; PVI, potential to ventricular interval; NEA, normal electrical axis; RAD, right axis deviation; RAO, right anterior oblique (view under fluoroscopy). [Colour figure can be viewed at wileyonlinelibrary.com]

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  FIGURE 2. Comparison of electrical and mechanical synchrony in subgroup patients who underwent LBBAP. To investigate the relationship between different electrical parameters with electrical synchrony and mechanical synchrony, patients who underwent LBBAP were divided into different groups according to the presence of LBB potential (a: positive, negative), QRS axis (b: normal, left deviation), and PVI (c: < 20 and > 20 ms). Stim‐LVAT and pQRSD were compared among the subgroups, respectively. No significant differences were documented in electrical synchrony, evaluated by pQRSD or stim‐LVAT, among the groups. No significant differences were documented in mechanical synchrony, evaluated by Tsd‐12‐LV, among the subgroups. LAD indicates left axis deviation; LBB, left bundle branch; LBBAP, left bundle branch area pacing; LVAT, left ventricular activation time; NEA, normal electrical axis; pQRSD, paced QRS duration; PVI, potential to ventricular interval; Tsd‐12‐LV, standard deviation of the time‐to‐peak contraction velocity in 12 left ventricular segments. [Colour figure can be viewed at wileyonlinelibrary.com]

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  FIGURE 3. Electrical synchrony and mechanical synchrony according to LBB potential, PVI, and pQRS axis. Patients underwent LBBAP were divided into six subgroups according to whether PVI was > 20 ms, LBB potential was recorded, or paced QRS axis was deviated. No differences in pQRSD (a), stim‐LVAT (b), or Tsd‐12‐LV (c) were documented in different subgroups, whether LBB potential existed or not, paced QRS axis was deviated or not, or the PVI was elongated or not. LBB indicates left bundle branch; LBBAP, left bundle branch area pacing; LVAT, left ventricular activation time; pQRSD, paced QRS duration; PVI, potential to ventricular interval; Tsd‐12‐LV, standard deviation of the time‐to‐peak contraction velocity in 12 left ventricular segments. [Colour figure can be viewed at wileyonlinelibrary.com]

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  FIGURE 4. QRS morphology and mechanical synchrony evaluated in different patients who underwent LBBAP. Paced QRS morphology and Tsd‐12‐LV were documented in patients who underwent LBBAP. (a) a patient with LBB potential, PVI < 20 ms and NEA, (b) a patient with LBB potential, PVI < 20 ms and LAD, (c) a patient with LBB potential, PVI > 20 ms and NEA, (d) a patient with LBB potential, PVI > 20 ms and LAD, (e) a patient without LBB potential and NEA, (f) a patient without LBB potential and LAD. No significant differences in Tsd‐12‐LV were recorded, irrespective of the existence of LBB potential, deviation of paced QRS axis, or the elongation of PVI. The LBB potential was marked with a star in the figure. LAD indicates left axis deviation; LBB, left bundle branch; LBBP, left bundle branch pacing; LBBAP, left bundle branch area pacing; NEA, normal electrical axis; PVI, potential to ventricular interval; Tsd‐12‐LV, standard deviation of the time‐to‐peak contraction velocity in 12 left ventricular segments; QRS, QRS complexes of electrocardiogram. [Colour figure can be viewed at wileyonlinelibrary.com]