부산대학교 도서관

Early repolarisation syndrome (ERS) is a well-recognized idiopathic electrocardiographic (ECG) phenomenon characterized by prominent J wave and ST-segment elevation. The syndrome shares cellular, ionic, and ECG similarities with the Brugada syndrome and, therefore, its arrhythmogenic potential still remains unknown. Moreover, there is no significant data regarding echocardiographic findings in ERS, and since the ECG changes are localized, we hypothesised that subtle parameters of systolic and/or diastolic function and synchrony might be affected.Methods: 18 subjects (27±5 years, 14 males) with infero-lateral ERS were compared to 14 healthy subjects with normal ECG, age- and sex- matched. 2D and 3D echocardiography, and tissue Doppler and speckle tracking imaging were performed and the following parameters were assessed: structural and functional conventional echo parameters, systolic and diastolic tissue velocities, global strain and strain rate, and cardiac synchrony (atrio-, intra-, and inter- ventricular).Results: By comparison with normals, subjects with ERS had increased intraventricular dyssynchrony (higher SD of time-to-peak Sm of the 12 left ventricular segments: 19.0±5.7 vs. 14.4±4.3, p<0.05), due mainly to an increased time-to-peak Sm of the infero-lateral segments (by comparison with septal times), whereas interventricular electromecanical delay was lower (16.9±8.6 vs. 31±9.5, p<0.001). However, parameters of longitudinal systolic function (strain and velocities), and global diastolic function (E/A: 1.9±0.2 vs. 1.5±0.2; E/Eʼ: 6.5±1.0 vs. 7.3±1.1, both p<0.05) were similar or even better in subjects with ERS Meanwhile, filling time was longer in subjects with ERS (57.7±4.1 vs. 52.8±4.7%, p<0.05), while all other structural and functional parameters were similar.Conclusion: Subjects with infero-lateral ERS have significant intraventricular dyssynchrony due to a prolonged electromechanical activation into the segments with ERS. These subtle changes, suggesting particular properties of the action potential in these segments, are not associated with any other structural or functional changes, however, on a long-term, this regional dyssynchrony might affect LV function and might induce arrhythmias