Department of Cardiology, Pomeranian Medical University, Szczecin, Poland.
Kardiol Pol. 2011;69(6):580-5.
Sudden cardiac death (SCD) is the main cause of death in patients with reduced left ventricular ejection fraction (LVEF). Implantation of an automatic cardioverter-defibrillator (ICD) significantly reduces mortality of these patients. T-wave alternans (TWA) analysis is a relatively new method of SCD risk stratification. However, it's prognostic role in patients with ICD has not yet been fully established.
To assess the predictive value of TWA in patients with previously implanted ICD.
The study included 67 patients with properly functioning ICD (54 men and 13 women, aged 62.2 ± 8.4 years). All patients underwent TWA analysis on the treadmill using the Cambridge Heart 2000 system. Results were considered as positive, negative or indeterminate. Each patient had at least 1 clinical control visit with ICD interrogation during the 12 ± ± 6 months of follow-up. The recurrence of sustained ventricular arrhythmias: ventricular tachycardia (VT) or ventricular fibrillation (VF) was analysed.
No significant relationship was found between previous infarction (p = 0.810), aetiology (p = 0.768), LVEF (p = 0.413) or age (p = 0.562) and the incidence of arrhythmia during follow-up. The results of TWA were not significantly different between patients with or without VT or VF. The TWA analysis identified patients with arrhythmia recurrences with a sensitivity of 62%, specificity of 49%, negative predictive value of 81%, and positive predictive value of 28%. The TWA performance was better in patients with non-ischaemic than ischaemic cardiomyopathy (negative predictive value: 100%, positive predictive value: 75%).
The TWA alternans was moderately effective for identification of patients with ICD and ventricular arrhythmia recurrences. The test was most useful for identification of patients with non-ischaemic cardiomyopathy who are of low arrhythmic risk.
心搏骤停（SCD）是左心室射血分数降低（LVEF）患者的主要死亡原因。植入自动除颤器（ICD）可显著降低此类患者的死亡率。T 波交替（TWA）分析是一种相对较新的 SCD 风险分层方法。然而，其在植入 ICD 的患者中的预后作用尚未完全确定。
评估 TWA 在先前植入 ICD 的患者中的预测价值。
该研究纳入了 67 名功能正常的 ICD 患者（54 名男性和 13 名女性，年龄 62.2±8.4 岁）。所有患者均在跑步机上使用 Cambridge Heart 2000 系统进行 TWA 分析。结果分为阳性、阴性或不确定。在 12±±6 个月的随访期间，每位患者至少有 1 次临床随访并进行 ICD 询问。分析持续性室性心律失常（VT 或 VF）的复发情况。
既往梗死（p=0.810）、病因（p=0.768）、LVEF（p=0.413）或年龄（p=0.562）与随访期间心律失常的发生率之间无显著关系。TWA 结果在发生 VT 或 VF 的患者与未发生 VT 或 VF 的患者之间无显著差异。TWA 分析对心律失常复发的识别率为 62%，特异性为 49%，阴性预测值为 81%，阳性预测值为 28%。TWA 在非缺血性心肌病患者中的表现优于缺血性心肌病患者（阴性预测值：100%，阳性预测值：75%）。
TWA 交替对识别 ICD 伴室性心律失常复发的患者具有中等有效性。该测试对识别心律失常风险较低的非缺血性心肌病患者最有用。
