Donzeau J P, Dechandol A, Marrot M, Lescure Ducay M, Queyreau J M, Berthoumieu H, Charrançon M, Goutner C
Clinique Pasteur, Toulouse.
Ann Cardiol Angeiol (Paris). 1994 May;43(5):256-61.
The authors report four observations: three are essentially clinical cases where sustained rate dependent left bundle branch block can induce syncope, where as there is no syncope when the same supraventricular tachycardia at the same frequency has narrow QRS complexes. The fourth case demonstrates the dramatic decrease of arterial electrophysiological slowly accelerated atrial pacing in a patient investigated for a loss of consciousness of unknown origin. The hemodynamic impairment due to intermittent left bundle branch block has been demonstrated even in patients with normal ventricular function. If there are critical hemodynamic events such as during fast supraventricular rhythms occurrence of a left bundle branch block may determinate a dramatic decrease of arterial pressure with syncope. Syncope of supraventricular tachycardias might be induced not only by very fast rate but also by functional left bundle branch block. It might have some interesting applications in the diagnosis of syncope when coexist electrophysiological data of supraventricular arrhythmia substrate and frequency dependent left bundle branch block.
其中三项本质上是临床病例，持续性频率依赖性左束支传导阻滞可诱发晕厥，而相同频率的室上性心动过速伴窄QRS波群时则无晕厥发生。第四例显示，在一名因不明原因意识丧失而接受检查的患者中，动脉电生理检查时缓慢加速心房起搏出现显著下降。即使在心室功能正常的患者中，间歇性左束支传导阻滞导致的血流动力学损害也已得到证实。如果存在严重的血流动力学事件，如在快速室上性心律期间出现左束支传导阻滞，可能会导致动脉压急剧下降并伴有晕厥。室上性心动过速导致的晕厥不仅可能由极快的心率引起，还可能由功能性左束支传导阻滞引起。当存在室上性心律失常基质的电生理数据和频率依赖性左束支传导阻滞时，这可能在晕厥的诊断中有一些有趣的应用。
