Intracardiac conduction time as a predictor of cardiac resynchronization therapy response: Results of the BIO|SELECT pilot study

Figures

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  Figure 1. The Sentus ProMRI OTW quadripolar left ventricular (LV) lead (Biotronik SE & Co. KG, Berlin, Germany) has a 2-D dual curve (“L” model) or a bend enhanced with a silicone screw (“S” model) for passive fixation in an LV coronary vein by stylet or by over-the-wire technique. The distances between adjacent electrodes are 21 mm (LV1tip-LV2ring), 20/15 mm (LV2ring-LV3ring, for L/S model), and 20/10 mm (LV3ring-LV4ring, for L/S model).

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  Figure 2. Example of measurement of electrical delays on the Biotronik Renamic (Biotronik SE & Co. KG, Berlin, Germany) programmer screen. Atrial, right ventricular (RV), and left ventricular (LV) electrograms were displayed at a sweep speed of 100 mm/s. The distance between 2 calipers was indicated in ms. A: RVs-LVs (31 ms); calipers are manually positioned to measure interval from the peak of the first fragmentation of RV wave pattern to the peak of the first fragmentation of LV wave pattern. B: RVp-LVs (134 ms), automatically measured by the programmer between the RV-pace marker and the LV-sense marker (calipers are not used but shown to demonstrate the interval approximately). C: LV1 tip pacing – LV4 ring sensing (59 ms); calipers are manually positioned on the LV pace marker and on the peak of the first fragmentation of LV wave pattern. D: LV4 ring pacing – LV1 tip sensing (90 ms); calipers are positioned as in panel C. In panels B–D, wave pattern cannot be shown during the blanking period after RV pacing and LV pacing. A = atrial; FF = far-field signal; p = paced; s = sensed.

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  Figure 3. Scatterplots showing interrelationship between the following: A: intrinsic and right ventricular (RV)-paced, B: left ventricular (LV)-paced and RV-paced, and C: LV-paced and intrinsic electrical delays. Correlation parameters (R2, P value) and the formula of the regression line are indicated. p = paced; s = sensed.

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  Figure 4. Interrelationship between left ventricular end-systolic volume (LVESV) change or composite cardiac resynchronization therapy benefit index and intrinsic (A,B), right ventricular (RV)-paced (C,D), and left ventricular (LV)-paced (E,F) electrical delays. Correlation parameters (R2, P value) and the formula of the regression line are indicated. For intrinsic delay, regression was determined using absolute values of the conduction time, which converted negative values (sensing at LV1 occurring earlier than at RV) to positive values. The regression lines in the plots are therefore kinked at 0 ms. p = paced; s = sensed.