Trzos Ewa, Kasprzak Jarosław D, Krzemińska-Pakuła Maria, Rechciński Tomasz, Wierzbowska-Drabik Karina, Uznańska Barbara, Śmiałowski Adam, Rudziński Tomasz, Kurpesa Małgorzata
Department of Cardiology, Biegański Hospital, Medical University of Lodz, Lodz, Poland.
Ann Noninvasive Electrocardiol. 2011 Jul;16(3):276-86. doi: 10.1111/j.1542-474X.2011.00443.x.
Nonsustained ventricular tachycardia (nVT) may have ominous implications for patients with hypertrophic cardiomyopathy (HCM). The microvolt T-wave alternans (TWA) has been proposed as a noninvasive tool-identifying patients at risk of sudden cardiac death and ventricular tachycardia/fibrillation (VT/VF). The aim of the study was to determine the significance of TWA in predicting nVT episodes and compare how other electrocardiographic parameters can predict the occurrence of nVT.
The study group consisted of 88 patients with HCM. TWA was assessed during exercise test using the CH2000 system. All patients underwent Holter monitoring (HM) within 2-4 weeks before TWA test (preexercise HM1) and immediately after (postexercise HM2). During HM, we analyzed: arrhythmias, QT intervals, the presence of late ventricular potentials (LP), heart rate variability, heart rate turbulence.
Depending on TWA results, the patients were divided into two groups: TWA+; 46 patients (52.3%) with positive/indeterminate results, and TWA-; 42 patients (47.7%) with negative results. The nVT episodes were more frequent among TWA(+) both in HM1 and HM2. The presence of TWA increases the risk of postexercise nVT over twenty times (OR = 21.03). Moreover, in HM1, QTc and LP, and in HM2, again QTc and N-terminal precursor of brain natriuretic peptide proved to be significant predictors of nVT. The addition of TWA to the models did not improve the arrhythmia risk assessment.
Repolarization abnormality plays an important role in generating nVT in patients with HCM, but TWA does not specifically predict the risk of arrhythmic end point.
非持续性室性心动过速（nVT）对于肥厚型心肌病（HCM）患者可能具有不祥的意义。微伏级T波电交替（TWA）已被提议作为一种识别有心脏性猝死和室性心动过速/心室颤动（VT/VF）风险患者的非侵入性工具。本研究的目的是确定TWA在预测nVT发作中的意义，并比较其他心电图参数如何预测nVT的发生。
研究组由88例HCM患者组成。使用CH2000系统在运动试验期间评估TWA。所有患者在TWA测试前2 - 4周内（运动前动态心电图监测1，preexercise HM1）和之后立即（运动后动态心电图监测2，postexercise HM2）进行动态心电图监测（HM）。在HM期间，我们分析了：心律失常、QT间期、心室晚电位（LP）的存在、心率变异性、心率震荡。
根据TWA结果，患者被分为两组：TWA阳性组；46例（52.3%）结果为阳性/不确定的患者，以及TWA阴性组；42例（47.7%）结果为阴性的患者。在HM1和HM2中，nVT发作在TWA阳性组中更频繁。TWA的存在使运动后nVT的风险增加超过二十倍（OR = 21.03）。此外，在HM1中，QTc和LP，以及在HM2中，再次是QTc和脑钠肽前体N末端被证明是nVT的重要预测因子。将TWA添加到模型中并未改善心律失常风险评估。
复极异常在HCM患者发生nVT中起重要作用，但TWA不能特异性预测心律失常终点的风险。
