Ridley Daryl P, Gula Lorne J, Krahn Andrew D, Skanes Allan C, Yee Raymond, Brown Mark L, Olson Walter H, Gillberg Jeffrey M, Klein George J
London Health Sciences Centre, London, Ontario N6A 5A5, Canada.
J Cardiovasc Electrophysiol. 2005 Jun;16(6):601-5. doi: 10.1046/j.1540-8167.2005.40474.x.
Inappropriate shocks from implantable cardioverter defibrillators (ICD) remain a significant clinical problem despite device discrimination algorithms. The atrial response to antitachycardia pacing (ATP) may determine the mechanism of 1:1 A:V tachycardia.
For this study we refer to sinus tachycardia, atrial tachycardia (AT), atrial fibrillation, and flutter as atrial tachycardia (AT), and all other tachycardia as "non-AT." Three atrial response patterns during the burst of ATP were determined. The atrial cycle length (ACL) may be unchanged (type 1) indicating AT. The ACL may show variation during ATP (type 2) indicating variable VA block and does not discriminate between an AT and a non-AT mechanism, in which case a default diagnosis of non-AT is made. The ACL may accelerate to the ATP cycle length (type 3) indicating entrainment. A VAAV response at the end of ATP was considered diagnostic of AT (type 3A) whereas a VAV or VVA response was considered a non-AT mechanism (type 3B). This algorithm was applied to ICD tracings from 68 episodes of spontaneous 1:1 A:V tachycardia that had 136 sequences of ATP administered. The rhythm "truth" was determined by consensus of two experienced clinicians.
The algorithm correctly identified AT with a sensitivity of 71.9% (95% CI: 67.1-73.6), and specificity of 95% (83.5-99.1). The PPV was 97.2% (90.9-99.5), and NPV 58.5% (51.4-61.0). Kappa was 0.57 (0.43-0.62). If used clinically the algorithm would have aborted 53.3% (8/15) of inappropriate shocks delivered into an AT-mechanism tachycardia and would not have withheld a shock for any episode of VT.
Analysis of atrial response patterns during and after ventricular ATP can successfully discriminate tachycardia mechanism and may reduce inappropriate ICD shocks.
尽管植入式心脏复律除颤器（ICD）有鉴别算法，但不适当电击仍是一个重大临床问题。心房对抗心动过速起搏（ATP）的反应可能决定1:1房室心动过速的机制。
在本研究中，我们将窦性心动过速、房性心动过速（AT）、心房颤动和心房扑动统称为房性心动过速（AT），将所有其他心动过速称为“非AT”。确定了ATP猝发期间的三种心房反应模式。心房周期长度（ACL）可能不变（1型），提示AT。ACL在ATP期间可能显示变化（2型），提示可变的室房阻滞，且无法区分AT机制和非AT机制，在这种情况下默认诊断为非AT。ACL可能加速至ATP周期长度（3型），提示拖带。ATP结束时的VAAV反应被认为可诊断为AT（3A型），而VAV或VVA反应被认为是非AT机制（3B型）。该算法应用于68例自发1:1房室心动过速的ICD记录，这些心动过速共进行了136次ATP序列。心律“真相”由两位经验丰富的临床医生共同确定。
该算法正确识别AT的敏感性为71.9%（95%CI：67.1 - 73.6），特异性为95%（83.5 - 99.1）。阳性预测值为97.2%（90.9 - 99.5），阴性预测值为58.5%（51.4 - 61.0）。kappa值为0.57（0.43 - 0.62）。如果临床应用该算法，将中止53.3%（8/15）针对AT机制心动过速的不适当电击，且不会对任何室性心动过速发作漏发电击。
分析心室ATP期间及之后的心房反应模式可成功鉴别心动过速机制，并可能减少ICD不适当电击。
