Left univentricular pacing for cardiac resynchronization therapy using rate-adaptive atrioventricular delay.

Figures

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  Figure 1.. The comparison between QRS complex pre- and post-operation. A patient with CHF was implanted with a dual-chamber pacemaker (Relia RED01, Medtronic, Inc., Minneapolis, MN, USA). (A): Pre-CRT (CLBBB, QRS duration was 200 ms under intrinsic atrioventricular conduction); (B): post-LUV pacing with RAAVD (QRS duration was 137 ms). CHF: congestive heart failure; CRT: cardiac resynchronization therapy; LUV: left univentricular; RAAVD: rate adaptive atrio-ventricular delay; RS/R-SD5 (Tracking index)

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  Figure 2.. QRS complex morphology at 5 deferent HR. (A): At average HR of 60 bpm, S/R ratio was 3.29; (B): at average HR of 70 beats/min, S/R ratio was 3.55; (C): at average HR of 80 beats/min, S/R ratio was 1.25; (D): at average HR of 90 beats/min, S/R ratio was 2.18; (E): at average HR of 100 beats/min, S/R ratio was 2.2. S/R ratio of five segments of HR was 2.49 ± 0.93, tracking index [RS/R-SD5] was 0.93 for this patient. HR: heart rate.

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  Figure 3.. The comparison between Ts-SD12 pre- and post-RAAVD LUV pacing. Bull eye view of real-time three-dimensional echocardiography showed that Ts-SD12 improved 12 months post-RAAVD LUV pacing. (A): Ts-SD12 was 92 ms pre-RAAVD LUV pacing; (B): Ts-SD12 was 70 ms 12 months post-RAAVD LUV pacing. LUV: left univentricular; RAAVD: rate adaptive atrio-ventricular delay.

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  Figure 4.. Chest X-ray pre- and one year post-PM implantation. (A): Pre-PM implantation, chest X-ray showed LV dilated. CTR was 56%, LVDD: 69 mm. (B): 12 months post-PM implantation, great reduction in ventricular size, the CTR decreased from 0.56 to 0.49, LVDD decreased from 69 mm to 53 mm. CRT: cardiac resynchronization therapy; CTR: cardiothoracic ratio; LV: left ventricular; LVDD: left ventricular diastolic diameter; PM: pacemaker.

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  Figure 5.. Correlation between RS/R-SD5 and improved LVEF. Correlation of SD of S/R ratio in lead V1 at five segments of HR (RS/R-SD5) with improved LVEF (ΔLVEF) in RAAVD LUV pacing group. RS/R-SD5 significantly negative correlated with improved LVEF (r = –0.427, P = 0.009). HR: heart rate; LVEF: left ventricular ejection fraction; LUV: left univentricular; RAAVD: rate adaptive atrio-ventricular delay; RS/R-SD5: standard deviation of the R/S ratio in lead V1 at five heart rate segments.