健康人微伏级T波电交替试验检测分析

微伏级T波电交替 (MTWA)与器质性心脏病恶性室性心律失常的发生密切相关。T波电交替偶见于正常人运动时。本研究的目的是探讨正常人静息和运动时MTWA的发生情况。用CambridgeHeart.HeartwaveTMsys tem心脏诊断系统 ,以频谱法检测 4 5例健康志愿者MTWA。结果 :所有受试者静息时MTWA阴性。运动负荷试验时 ,非持续性MTWA 5例 (11.11% ) ,持续性MTWA 2例 (4.4 4 % ) ,1例阈值心率 <110次 /分 ,另一例发作心率>110次 /分。 4 5例中 ,MTWA阳性 1例 (2 .2 2 % ) ,但持续时间短暂 (1min) ,不确定性 2例 (4.4 4 % ) ,阴性 4 2例(93.33% )。结论 :健康人MTWA阳性发生率低 (2 .2 2 % ) ,短暂的MTWA无恶性室性心律失常的临床意义。

Prevalence of T Wave Alternans in Healthy Subjects

Microvolt T wave alternans (MTWA) has been associated with malignant ventricular arrhythmias in patients with structural heart disease. Microvolt T wave alternans has been observed sporadically in healthy persons during strenuous exercise.The aim of this study was to investigate the prevalence of TWA in healthy subjects at rest and during exercise.MTWA was assessed in 45 healthy volunteers with spectral method using Cambridge Heart. Heartwave TM system. Results: MTWA was not observed in any individual at rest.Nonsustained TWA were observed during exercise in five subjects(11.11%). Sustained TWA was observed in two individuals (4.44%). In one of these two individuals sustained TWA was recorded at heart rate >110 bpm. In the other TWA was observed at an onset heart rate of <110 bpm. MTWA was positive in 1 individual(2.22%) and indeterminate in 2 individuals(4.44%) and negative in 42 individuals(93.33%). Positive TWA has short transient intervals about a duration of one minute. Conclusion:The prevalence of exercise related positive TWA in healthy individuals is low(2.22%). Short transient intervals of TWA has no clinical impact with respect to a higher vulnerability to ventricular arrhythmias.