Tritto M, Dicandia C D, Calabrese P
Division of Cardiology, Oncology Institute, Bari, Italy.
Int J Cardiol. 1997 Oct 31;62(1):37-45. doi: 10.1016/s0167-5273(97)00190-3.
We evaluated the feasibility and usefulness of overdrive atrial pacing to identify the relationship between atrial and ventricular activation in supraventricular tachycardias with a stable 1:1 atrio-ventricular (AV) conduction ratio during a transesophageal electrophysiological investigation. Overdrive atrial stimulation was performed in 42 consecutive patients (11 males and 31 females; mean age 49 +/- 17 years) during AV junctional reentrant tachycardia, orthodromic AV reentrant tachycardia and ectopic atrial tachycardia (22, 13 and seven subjects, respectively). Trains of 12 stimuli at a constant rate were introduced starting at a cycle length 10 ms shorter than the tachycardia cycle length; stimulation was repeated with a 10-ms decrement in pacing cycle length at each step until tachycardia terminated and/or second-degree AV block occurred. The difference between the VA interval duration at baseline and in the first post-pacing tachycardia beat was measured at each step and provided identification of the AV relationship. At least one post-pacing VA interval was evaluable in 90% of the cases and measured 2 +/- 4 and 1 +/- 3 ms in AV junctional and AV reentrant tachycardia groups, respectively, and 83 +/- 42 ms in the ectopic atrial tachycardia group (P < 0.0000001 ectopic atrial tachycardia group vs. others). When three or more post-pacing VA intervals were obtained during the same tachycardia, a curve was constructed by plotting their values against the corresponding pacing cycle lengths. A curve could be constructed in 36% of the cases and was flat in all patients with AV junctional and AV reentry, while it was completely irregular in the ectopic atrial tachycardia group (P < 0.003). The analysis of post-pacing VA interval behaviour in response to overdrive atrial stimulation provides a rapid and reliable differentiation between supraventricular tachycardias with 1:1 AV conduction ratio during a transesophageal electrophysiological study.
在经食管电生理检查期间，我们评估了超速心房起搏在确定室上性心动过速时心房与心室激动关系方面的可行性和实用性，这些室上性心动过速具有稳定的1:1房室（AV）传导比例。在42例连续患者（11例男性和31例女性；平均年龄49±17岁）中进行了超速心房刺激，这些患者分别患有房室交界区折返性心动过速、顺向性房室折返性心动过速和异位房性心动过速（分别为22例、13例和7例）。以比心动过速周期长度短10 ms的周期长度开始，引入以恒定频率的12次刺激序列；每一步以10 ms的步长递减起搏周期长度重复刺激，直到心动过速终止和/或发生二度房室传导阻滞。在每一步测量基线时和起搏后第一个心动过速搏动时的VA间期持续时间之差，并确定房室关系。在90%的病例中至少有一个起搏后VA间期可评估；在房室交界区和房室折返性心动过速组中分别为2±4和1±3 ms，在异位房性心动过速组中为83±42 ms（异位房性心动过速组与其他组相比，P<0.0000001）。当在同一心动过速期间获得三个或更多起搏后VA间期时，通过将其值与相应的起搏周期长度作图构建一条曲线。在36%的病例中可以构建曲线，在所有房室交界区和房室折返性心动过速患者中曲线是平坦的，而在异位房性心动过速组中曲线完全不规则（P<0.003）。在经食管电生理研究期间，对超速心房刺激后的起搏后VA间期行为进行分析，可快速可靠地区分具有1:1房室传导比例的室上性心动过速。
