Maybhate Anil, Hao Steven C, Iwai Sei, Lee Jae Ung, Guttigoli Amit B, Stein Kenneth M, Lerman Bruce B, Christini David J
Weill Medical College of Cornell University, 520 East 70th Street, Starr-463, New York, NY 10021, USA.
IEEE Trans Biomed Eng. 2005 Jul;52(7):1188-94. doi: 10.1109/TBME.2005.847537.
Mechanistic links have been suggested between repolarization alternans (RPA) and the onset of ventricular tachycardia (VT) and/or fibrillation. Endocardial detection of RPA may, therefore, be an important step in future device-based treatments of arrhythmias. Here, we investigate if RPA could be detected during acute ischemia using an implantable cardioverter defibrillator (ICD) lead (tip to distal coil) located in the right ventricular apex. In 18 pigs, the right coronary (n = 10) or left anterior descending coronary (n = 8) artery was occluded for 10 min using a balloon catheter, followed by reperfusion for 30 min, and re-occlusion for 30 min. RPA magnitude, computed using the modified moving average (MMA) method, showed a sharp increase in all 18 animals, from a mean baseline level of 1.9 +/- 1.3 mV to 3.0 +/- 1.3 mV during first occlusion (p < 0.001). RPA magnitude showed a prominent increase in 10 animals during re-occlusion, from a mean baseline level of 1.7 +/- 1.0 mV to 3.3 +/- 1.5 mV (p < 0.001). The protocol was terminated during the first two stages of occlusion and reperfusion for the remaining 8 animals due to the occurrence of ventricular fibrillation (VF). These results confirm that RPA increases under ischemic conditions and that it is possible to detect and track RPA dynamics with an ICD lead that is positioned in a clinically realistic location. Such an approach may be useful in formulating improved arrhythmia detection and control algorithms.
复极交替（RPA）与室性心动过速（VT）和/或颤动的发作之间已被提出存在机制联系。因此，心内膜检测RPA可能是未来基于设备的心律失常治疗中的重要一步。在此，我们研究是否可以使用位于右心室心尖的植入式心脏复律除颤器（ICD）导线（尖端至远端线圈）在急性缺血期间检测到RPA。在18头猪中，使用球囊导管将右冠状动脉（n = 10）或左前降支冠状动脉（n = 8）闭塞10分钟，随后再灌注30分钟，然后再次闭塞30分钟。使用改良移动平均（MMA）方法计算的RPA幅度在所有18只动物中均显示出急剧增加，从平均基线水平1.9±1.3 mV增加到首次闭塞期间的3.0±1.3 mV（p < 0.001）。在再次闭塞期间，10只动物的RPA幅度显著增加，从平均基线水平1.7±1.0 mV增加到3.3±1.5 mV（p < 0.001）。由于发生心室颤动（VF），其余8只动物在闭塞和再灌注的前两个阶段终止了实验方案。这些结果证实，RPA在缺血条件下会增加，并且可以使用位于临床实际位置的ICD导线检测和跟踪RPA动态。这种方法可能有助于制定改进的心律失常检测和控制算法。
