Christini David J, Stein Kenneth M, Hao Steven C, Markowitz Steven M, Mittal Suneet, Slotwiner David J, Iwai Sei, Das Mithilesh K, Lerman Bruce B
Department of Medicine, Division of Cardiology, Weill Medical College of Cornell University, New York, NY 10021, USA.
IEEE Trans Biomed Eng. 2003 Jul;50(7):855-62. doi: 10.1109/TBME.2003.813535.
Repolarization alternans (RPA) is prognostic of sudden cardiac death and is thought to be mechanistically linked to the initiation of ventricular tachyarrhythmias. Thus, implantable cardiac device detection of RPA may be therapeutically valuable. Because alternans detection is currently limited to surface electrocardiograms, we investigated whether RPA could be measured using a single right-ventricular endocardial lead in humans. Such a location was chosen because it is consistent with the requirements for long-term implantable-device implementation. During diagnostic electrophysiological testing, 28 patients (23 male, 5 female; 61 +/- 15 years) were evaluated for surface T-wave alternans (TWA; the current "gold standard" for RPA detection) and endocardial RPA during 5 min of 550-ms right-atrial pacing. Power spectral analysis indicated that 11/28 patients had both surface TWA and endocardial RPA, 9/28 patients had neither, and 8/28 patients had discordant results (71% concordance; p = 0.02). Importantly, unlike surface TWA, endocardial RPA was detectable on a beat-to-beat basis. Given the putative mechanistic link between RPA and ventricular arrhythmias, beat-to-beat endocardial RPA detection might be of diagnostic or therapeutic utility.
复极交替（RPA）是心脏性猝死的预后指标，被认为在机制上与室性快速性心律失常的起始有关。因此，植入式心脏设备检测RPA可能具有治疗价值。由于目前交替现象的检测仅限于体表心电图，我们研究了是否可以使用单根右心室心内膜导线在人体中测量RPA。选择这样的位置是因为它符合长期植入设备的要求。在诊断性电生理检查期间，对28例患者（23例男性，5例女性；年龄61±15岁）在550毫秒右心房起搏5分钟期间进行了体表T波交替（TWA；目前RPA检测的“金标准”）和心内膜RPA评估。功率谱分析表明，28例患者中有11例同时存在体表TWA和心内膜RPA，9例既无体表TWA也无心内膜RPA，8例结果不一致（一致性为71%；p = 0.02）。重要的是，与体表TWA不同，心内膜RPA可以逐搏检测到。鉴于RPA与室性心律失常之间可能存在的机制联系，逐搏的心内膜RPA检测可能具有诊断或治疗价值。
