
Occlusive thrombosis in myocardial bridging
1993; Elsevier BV; Volume: 125; Issue: 6 Linguagem: Inglês
10.1016/0002-8703(93)90772-2
ISSN1097-6744
AutoresSimone G. Ramos, AndréP. Montenegro, Paulo Roberto Félix, Dayr Kiomizu Kazava, Marcos A. Rossi,
Tópico(s)Cardiac Structural Anomalies and Repair
ResumoBackground: Isolated myocardial bridging (MB) often is considered to be an unimportant angiographic finding; however, its association with cardiovascular event has been shown. In this study we aimed to assess exercise-induced electrocardiographic (ECG) changes and susceptibility to arrhythmia in patients with MB. Method: 21 consecutive patients who had angiographically proven MB (group I) and 25 subjects (group II) who had normal coronary arteries underwent exercise test using Bruce protocol. Before and after the exercise test the changes in QT interval duration and dispersion were compared. Results: Baseline characteristics of both groups were similar. Heart rate significantly increased after exercise test in both groups. In group I, after exercise mean QTmax and QTmin durations did not change significantly compared to baseline values, respectively. (QTmax: 411±20 vs. 421±18 ms, p>0.05 and QTmin: 380±12 vs. 378±10 ms, p>0.05). However, following exercise test QT dispersion (QTd) and corrected QT dispersion (QTcd) significantly increased when compared to baseline values, respectively. (34±13 vs. 66±14 ms, p<0.05 and 37±14 vs. 69±17 ms, p 0.05 and QTmin: 390±11 vs. 387±10 ms, p>0.05; QTd: 25±14 vs. 31±16 ms, p>0.05; QTcd: 27±15 vs. 33±17 ms, p>0.05). Conclusion: Treadmill exercise test significantly increased QT dispersion in patients with MB. This increase may result from exercise-induced ischemia at the area perfused by bridged artery.
Referência(s)