Giustetto Carla, Scrocco Chiara, Schimpf Rainer, Maury Philippe, Mazzanti Andrea, Levetto Marco, Anttonen Olli, Dalmasso Paola, Cerrato Natascia, Gribaudo Elena, Wolpert Christian, Giachino Daniela, Antzelevitch Charles, Borggrefe Martin, Gaita Fiorenzo
Division of Cardiology, Department of Medical Sciences, University of Torino, 'Città della Salute e della Scienza' Hospital, C.so Bramante 88, 10126 Torino, Italy
Division of Cardiology, Department of Medical Sciences, University of Torino, 'Città della Salute e della Scienza' Hospital, C.so Bramante 88, 10126 Torino, Italy.
Europace. 2015 Apr;17(4):628-34. doi: 10.1093/europace/euu351.
Short QT syndrome (SQTS) is a rare arrhythmogenic inherited heart disease. Diagnosis can be challenging in subjects with slightly shortened QT interval at electrocardiogram. In this study we compared the QT interval behaviour during exercise in a cohort of SQTS patients with a control group, to evaluate the usefulness of exercise test in the diagnosis of SQTS.
Twenty-one SQTS patients and 20 matched control subjects underwent an exercise test. QT interval was measured at different heart rates (HRs), at rest and during effort. The relation between QT interval and HR was evaluated by linear regression analysis according to the formula: QT = β ×HR + α, where β is the slope of the linear relation, and α is the intercept. Rest and peak exercise HRs were not different in the two groups. Short QT syndrome patients showed lower QT intervals as compared with controls both at rest (276 ± 27 ms vs. 364 ± 25 ms, P < 0.0001) and at peak exercise (228 ± 27 ms vs. 245 ± 26 ms, P = 0.05), with a mean variation from rest to peak effort of 48 ± 14 ms vs. 120 ± 20 ms (P < 0.0001). Regression analysis of QT/HR relationship revealed a less steep slope for SQTS patients compared with the control group, never exceeding the value of -0.90 ms/beat/min (mean value -0.53 ± 0.15 ms/beat/min vs. -1.29 ± 0.30 ms/beat/min, P < 0.0001).
Short QT syndrome patients show a reduced adaptation of the QT interval to HR. Exercise test can be a useful tool in the diagnosis of SQTS.
短QT综合征（SQTS）是一种罕见的致心律失常遗传性心脏病。对于心电图QT间期轻度缩短的患者，诊断可能具有挑战性。在本研究中，我们比较了一组短QT综合征患者与对照组在运动期间的QT间期行为，以评估运动试验在短QT综合征诊断中的作用。
21例短QT综合征患者和20例匹配的对照受试者接受了运动试验。在静息和运动时，于不同心率（HR）下测量QT间期。根据公式QT =β×HR +α通过线性回归分析评估QT间期与HR之间的关系，其中β是线性关系的斜率，α是截距。两组的静息和运动峰值心率无差异。短QT综合征患者在静息时（276±27毫秒对364±25毫秒，P<0.0001）和运动峰值时（228±27毫秒对245±26毫秒，P = 0.05）的QT间期均低于对照组，静息至运动峰值的平均变化为48±14毫秒对120±20毫秒（P<0.0001）。QT/HR关系的回归分析显示，与对照组相比，短QT综合征患者的斜率较平缓，从未超过-0.90毫秒/次/分钟的值（平均值-0.53±0.15毫秒/次/分钟对-1.29±0.30毫秒/次/分钟，P<0.0001）。
短QT综合征患者的QT间期对HR的适应性降低。运动试验可能是短QT综合征诊断中的一个有用工具。
