El Camino Hospital, Mountain View, California; St Helena Hospital, St Helena, California.
Department of Medicine, Stanford University School of Medicine, Stanford, California.
Heart Rhythm. 2019 May;16(5):717-723. doi: 10.1016/j.hrthm.2018.11.021. Epub 2018 Nov 20.
The postpacing interval (PPI) minus the tachycardia cycle length (TCL) is frequently used to investigate tachycardias. However, a variety of issues (eg, failure to entrain, decremental conduction, and oscillating TCLs) can make interpretation of the PPI-TCL challenging.
The purpose of this study was to investigate a novel maneuver to confirm the PPI-TCL value without using either the ventricular PPI or the TCL interval and to assess the ability of this maneuver to identify decremental conduction and differentiate supraventricular tachycardias.
We analyzed 77 intracardiac recordings from patients (age 25 ± 20 years; 40 female) who underwent catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) or orthodromic reciprocating tachycardia (ORT) with a concealed pathway. We calculated the PPI-TCL, the AH-corrected PPI-TCL, and estimated the PPI-TCL using "dual-chamber entrainment" calculated as [PPI - TCL = Stim(A→V) + Stim(V→A) - PPI].
The PPI-TCL calculated by dual-chamber entrainment highly correlated with the observed and AH-corrected PPI-TCL (R = 0.79 and 0.96, respectively; P <.001]. A dual-chamber entrainment PPI-TCL value of 80 ms correctly differentiated all AVNRT from septal ORT cases, whereas the standard PPI-TCL and AH-corrected PPI-TCL methods were incorrect in 14% and 6% of cases, respectively. Dual-chamber entrainment identified 3 ± 10 ms of additional decremental conduction beyond AH prolongation, including 4 pathways with significant (>10 ms) decrement.
Dual-chamber entrainment estimates the PPI-TCL value without using either the ventricular PPI or the TCL interval. This maneuver adjusts for all decremental conduction, including within concealed pathways, where a dual-chamber entrainment PPI-TCL value >80 ms favors AVNRT over ORT. This maneuver can be used to verify the observed PPI-TCL value in challenging cases.
起搏后间期（PPI）减去心动过速周期长度（TCL）常用于研究心动过速。然而，多种问题（如失夺获、递减传导和 TCL 波动）可能使 PPI-TCL 的解释变得具有挑战性。
本研究旨在探讨一种新的操作方法，该方法无需使用心室 PPI 或 TCL 间期即可确认 PPI-TCL 值，并评估该操作方法识别递减传导和区分室上性心动过速的能力。
我们分析了 77 例接受房室结折返性心动过速（AVNRT）或显性顺向型心动过速（ORT）经导管消融治疗的患者的 77 份心内记录（年龄 25 ± 20 岁；40 例女性）。我们计算了 PPI-TCL、校正 AH 的 PPI-TCL 和使用“双腔夺获”计算的估计 PPI-TCL，计算公式为[PPI-TCL = Stim(A→V) + Stim(V→A) - PPI]。
双腔夺获计算的 PPI-TCL 与观察到的和校正 AH 的 PPI-TCL 高度相关（R 分别为 0.79 和 0.96，P<.001]）。双腔夺获 PPI-TCL 值为 80 ms 可正确区分所有 AVNRT 与间隔 ORT 病例，而标准 PPI-TCL 和校正 AH 的 PPI-TCL 方法在 14%和 6%的病例中是错误的。双腔夺获识别出除 AH 延长之外的 3 ± 10 ms 的额外递减传导，包括 4 条具有显著（>10 ms）递减的途径。
双腔夺获无需使用心室 PPI 或 TCL 间期即可估计 PPI-TCL 值。该操作方法调整了所有递减传导，包括在隐匿性途径中，双腔夺获 PPI-TCL 值>80 ms 有利于 AVNRT 而不是 ORT。该操作方法可用于在具有挑战性的情况下验证观察到的 PPI-TCL 值。
