Rivera Santiago, De La Paz Ricapito Maria, Conde Diego, Verdu Mariano Badra, Roux Jean François, Paredes Félix Ayala
Division of Cardiology, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Canada.
Pacing Clin Electrophysiol. 2014 Sep;37(9):1100-5. doi: 10.1111/pace.12394. Epub 2014 Apr 2.
Pseudo ischemic ST segment changes during supraventricular tachycardia (SVT) are not yet fully understood. Our aim was to determine whether venticulo-atrial (VA) conduction during SVT may be a possible mechanism for ST depression (STd) in SVT.
Patients undergoing SVT ablation (2010-2012) were analyzed (n = 72).Typical atrioventricular node reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) were included. Those with STd were compared to those without STd. VA interval length, tachycardia cycle length (TCL), and retrograde P-wave activation during SVT were assessed. Retrograde P waves arriving simultaneously with the ST segment (PWST) during SVT were considered, whenever an atrial electrogram (measured from the high right atrium) was "on time" with the ST segment.
Patients with STd during SVT presented longer VA intervals than those without STd (VA 100 ± 37 ms vs VA 69 ± 22 ms; P = 0.006). No differences in TCL were observed (TCL 333 ± 35 ms vs TCL 360 ± 22 ms; P = 0.1). PWST was observed in 38.5% of patients with AVNRT and STd versus 0% in those without STd. The TCL was similar in both groups (355 ± 25 ms vs 334 ± 18 ms; P = 0.1). In patients with AVRT and STd, PWST was present in 81% of cases versus 0% in those without STd. The TCL was also similar (330 ± 29 ms vs 346 ± 17 ms; P = 0.1).
STd during SVT is observed at long VA intervals when the retrograde P wave matches the ST segment, without dependence on the TCL. This suggests that STd is not necessarily rate dependent but a result of a fusion between the ST segment and the P wave.
室上性心动过速（SVT）期间的假性缺血性ST段改变尚未完全明确。我们的目的是确定SVT期间的室房（VA）传导是否可能是SVT中ST段压低（STd）的一种机制。
分析2010年至2012年接受SVT消融治疗的患者（n = 72）。纳入典型房室结折返性心动过速（AVNRT）和房室折返性心动过速（AVRT）。将有STd的患者与无STd的患者进行比较。评估SVT期间的VA间期长度、心动过速周期长度（TCL）和逆行P波激动情况。当心房电图（从高位右心房测量）与ST段“同步”时，考虑SVT期间与ST段同时出现的逆行P波（PWST）。
SVT期间有STd的患者的VA间期长于无STd的患者（VA 100±37毫秒对VA 69±22毫秒；P = 0.006）。未观察到TCL有差异（TCL 333±35毫秒对TCL 360±22毫秒；P = 0.1）。在有STd的AVNRT患者中，38.5%观察到PWST，而无STd的患者中这一比例为0%。两组的TCL相似（355±25毫秒对334±18毫秒；P = 0.1）。在有STd的AVRT患者中，81%的病例出现PWST，而无STd的患者中这一比例为0%。TCL也相似（330±29毫秒对346±17毫秒；P = 0.1）。
当逆行P波与ST段匹配时，在长VA间期观察到SVT期间的STd，且不依赖于TCL。这表明STd不一定与心率相关，而是ST段与P波融合的结果。
