Thambo J B, Bordachar P, Lafitte S, Crepin D, Garrigue S, Reuter S, Roudaut R, Haïssaguerre M, Clementy J, Jimenez M
Hôpital cardiologique du Haut-Lévêque, service des maladies cardiovasculaires congénitales de l'enfant et de l'adulte, Pessac.
Arch Mal Coeur Vaiss. 2005 May;98(5):519-23.
In patients with congenital heart block (CHB), dual-chamber pacing restores physiological heart rate and atrio-ventricular synchronization. However, patients with narrow QRS junctional escape rhythm may be deleteriously affected by long-term, permanent, apical ventricular pacing. We assessed the impact of apical ventricular pacing on echocardiographic ventricular dyssynchrony and hemodynamic parameters.
Fourteen CHB adults (23 +/- years, 58% male), with a DDD transvenous pacemaker and a junctional escape rhythm (QRS<120 ms) before implantation, were studied. Echocardiography coupled with tissue Doppler imaging (TDI) and Strain rate was performed in spontaneous rhythm (VVI mode 30/mn) and during atrio-synchronized ventricular pacing.
The heart rate (43 +/- 09 vs 68 +/- 07: p<0.01), cardiac output (2.9 +/- 0.7 vs 3.7 +/- 0.6 L/min) and left ventricular filling time (325 +/- 38 vs 412 +/- 51 ms; p<0.01) were significantly less in the escape spontaneous rhythm compared with atrio-ventricular synchronized apical pacing. However, interventricular dyssynchrony (28 +/- 12 vs 59 +/- 25 ms, p<0.05), intra-left ventricular dyssynchrony (36 +/- 11 vs 57 +/- 29 ms; p<0.05), extent of left ventricular myocardium displaying delayed longitudinal contraction (26 +/- 10 vs 39 +/- 17%: p<0.05) were significantly less in the escape rhythm compared with paced rhythm.
Once implanted with a DDD pacemaker, CHB patients present with increased cardiac output secondary to the restoration of physiological heart rate and improved diastolic function. However, the apical site is not optimal, as it creates detrimental ventricular dyssynchrony in patients with previous nearly physiological ventricular activation. Alternative pacing sites should be investigated.
在先天性心脏传导阻滞（CHB）患者中，双腔起搏可恢复生理心率和房室同步性。然而，QRS波窄的交界性逸搏心律患者可能会受到长期、永久性心尖部心室起搏的不利影响。我们评估了心尖部心室起搏对超声心动图心室不同步性和血流动力学参数的影响。
研究了14例CHB成年患者（23±岁，58%为男性），这些患者植入了DDD经静脉起搏器，植入前有交界性逸搏心律（QRS<120 ms）。在自身心律（VVI模式30次/分钟）和房室同步心室起搏期间，进行了超声心动图检查，并结合组织多普勒成像（TDI）和应变率分析。
与房室同步心尖部起搏相比，逸搏自身心律时的心率（43±0.9对68±0.7：p<0.01）、心输出量（2.9±0.7对3.7±0.6 L/分钟）和左心室充盈时间（325±38对412±51 ms；p<0.01）明显更低。然而，与起搏心律相比，逸搏心律时的心室间不同步性（28±12对59±25 ms，p<0.05）、左心室内不同步性（36±11对57±29 ms；p<0.05）、显示延迟纵向收缩的左心室心肌范围（26±10对39±17%：p<0.05）明显更小。
一旦植入DDD起搏器，CHB患者的心输出量会因生理心率的恢复和舒张功能的改善而增加。然而，心尖部起搏部位并非最佳，因为它会在先前心室激活接近生理状态的患者中造成有害的心室不同步性。应研究其他起搏部位。
