The relationship between myocardial bridges and myocardial repolarization

Abstract

Background: Although the muscular bridge (MB) which seen in the coronary arteries is known to be a benign condition, it is reported to be associated with adverse cardiac events in some studies. Although some condition such as coronary ischemia have been blamed in the occurrence of these adverse events, it is thought that the negative effects of myocardial electrical conduction will contribute to this situation.In this study, the relationship between electrocardiography parameters that demonstrate the electrical activity of the heart and the muscular bridgewas investigated.

Material and Methods: This study included 36 patients (26 males, mean age 56 years) who were diagnosed with MB and 36 patients with normal coronary artery (30 male, mean age 51 years). 12- lead electrocardiography (ECG) was performed in supine position and QT interval, QT corrected (QTc), Tp-Te interval, Tp-Te/QT and Tp-Te/QTc measurements were performed. These parameters were compared between groups.

Results: There were no significant differences between MB group and control group in terms of clinical and baseline demographic characteristics However, QT interval, QTc, Tp-Te interval, Tp-Te / QT and Tp-Te / QTc were significantly higher in the MB group. (360 ± 1.9 vs 355±2.3, p <0.001; 428.1 ± 1.6 vs 417.3±1.4, p <0.001; 83.3 ± 1.4 vs 72.1±1.3, p <0.001; 0.24 ± 0.005 vs 0.2±0.004, p <0.001; 0.2±0.003 vs 0.17±0.003, p <0.001). Multivariate analysis was performed to determine the independent predictors of the Tp-e interval. The length of MB was detected as an independent predictor of Tp-Te interval. (β = 0.530, p = 0.005)

Conclusion: Length of MB is an independent predictor of Tp-Te interval.

Keywords

• Myocardial bridge,Tp-Te interval,Bridge length

Miyokardiyal köprülenme ve miyokardiyal repolarizasyon ilişkisi

Abstract

Amaç: Koroner arterlerde görülen Müsküler köprü (MK) iyi huylu bir durum olarak bilinmesine rağmen, bazı çalışmalarda olumsuz kardiyak olaylar ile ilişkisinin olduğu belirtilmektedir. Bu olumsuz olayların meydana gelmesinde koroner iskemi gibi bazı durumlar suçlansa da, miyokardiyal elektriksel iletimdeki olumsuzlukların da buna katkıda bulunacağı düşünülmektedir. Bu çalışma da kalbin elektriksel aktivitesini gösteren elektrokardiyografi parametreleri ile müsküler köprü arasındaki ilişki incelenmiştir.

Materyal ve Metod: Bu çalışmaya MK olan 36 hasta (26 erkek, yaş ortalaması 56 yıl) ve normal koroner arteri olan MK olmayan 36 kişi (30 erkek, yaş ortalaması 51yıl) kontrol grubu olarak kalınmıştır. İstirahat halinde yatar pozisyonda 12 kanallı elektrokardiyografi (EKG) çekilerek QT intervali, QT corrected (QTc), Tp-Te intervali, Tp-Te/QT ve Tp-Te/QTc ölçümleri yapılmıştır. Bu parametreler, gruplar arasında karşılaştırıldı.

Bulgular: MK ve kontrol grubu arasında klinik ve bazal demografik özellikler açısından anlamlı farklılık saptanmadı. Ancak, MK grubunda QT intervali, QTc, Tp-Te intervali, Tp-Te/QT ve Tp-Te/QTc anlamlı olarak yüksekti. (Sırasıyla 360±1.9’e karşın 355±2.3, p<0,001; 428.1±1,6‘e karşın. 417.3±1.4, p<0,001; 83.3±1.4‘e karşın 72.1±1.3, p<0,001; 0,24±0,005’e karşın0.2±0.004, p<0,001; 0,2±0,003’e karşın 0.17±0.003 p<0,001). Tp-e intervalinin bağımsız prediktörlerini belirlemek amacıyla multivariate analiz yapıldı. MB uzunluğu Tp-Te intervalinin bağımsız öngördürücüsü olarak saptandı. (β=0.530, p = 0.005)

Sonuç: MK uzunluğu, Tp-Te intervalinin bağımsız bir ön gördürücüsüdür.

Keywords

• Myokardiyal köprülenme,Tp-Te interval,Miyokardiyal köprü uzunluğu

References

1. 1. Çiçek D, Kalay N, Müderrisoğlu H. Incidence, clinical characteristics, and 4-year follow-up of patients with isolated myocardial bridge: a retrospective, single-center, epidemiologic, coronary arteriographic follow-up study in southern Turkey. Cardiovascular Revascularization Medicine. 2011;12(1):25-8.
2. 2. Möhlenkamp S, Hort W, Ge J, Erbel R. Update on myocardial bridging. Circulation. 2002;106(20):2616-22.
3. 3. Alegria JR, Herrmann J, Holmes Jr DR, et al. Myocardial bridging. European heart journal. 2005;26(12):1159-68.
4. 4. Aytan P, Ulusal G, Yenigun EC, et al. Muscular bridge causing non-ST-segment elevation myocardial infarction/ST-elevasyonsuz miyokard infarktusune neden olan miyokardiyal kopruleme. The Anatolian Journal of Cardiology (Anadolu Kardiyoloji Dergisi). 2006;6(4):374-6.
5. 5. Berry JF, von Mering GO, Schmalfuss C, et al. Systolic compression of the left anterior descending coronary artery: a case series, review of the literature, and therapeutic options including stenting. Catheterization and cardiovascular interventions. 2002;56(1):58-63.
6. 6. Akçevin A, Türkoğlu H, Bayer V, et al. Myocardial Bridging Over Left Anterior Descending Coronary Artery Surgical Therapy and Results. Turkish Journal of Thoracic and Cardiovascular Surgery.6(2):125-9.
7. 7. Erdogan HI, Gul EE, Gok H. Relationship between myocardial bridges and arrhythmic complications. The Journal of invasive cardiology. 2012;24(11):E300-2.
8. 8. Feld H, Guadanino V, Hollander G, et al. Exercise-induced ventricular tachycardia in association with a myocardial bridge. Chest. 1991;99(5):1295-6.

9. 9. Cutler D, Wallace JM. Myocardial bridging in a young patient with sudden death. Clinical cardiology. 1997;20(6):581-3.
10. 10. Kors JA, van Eck HJR, van Herpen G. The meaning of the Tp-Te interval and its diagnostic value. Journal of electrocardiology. 2008;41(6):575-80.
11. 11. Gupta P, Patel C, Patel H, Narayanaswamy S, et al. Tp-e/QT ratio as an index of arrhythmogenesis. Journal of electrocardiology. 2008;41(6):567-74.
12. 12. Erikssen G, Liestol K, Gullestad L, et al. The terminal part of the QT interval (T peak to T end): a predictor of mortality after acute myocardial infarction. Annals of Noninvasive Electrocardiology. 2012;17(2):85-94.
13. 13. Day CP, McComb JM, Campbell R. QT dispersion: an indication of arrhythmia risk in patients with long QT intervals. Heart. 1990;63(6):342-4.
14. 14. Quiñones MA, Otto CM, Stoddard M, et al. Recommendations for quantification of Doppler echocardiography: a report from the Doppler Quantification Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography. Journal of the American Society of Echocardiography. 2002;15(2):167-84.
15. 15. Aksan G, Nar G, İnci S, et al. Exercise-induced repolarization changes in patients with isolated myocardial bridging. Medical science monitor: international medical journal of experimental and clinical research. 2015;21:2116.
16. 16. Tenekecioglu E, Karaagac K, Yontar OC, et al. Evaluation of Tp-Te Interval and Tp-Te/QT ratio in patients with coronary slow flow Tp-Te/QT ratio and coronary slow flow. The Eurasian journal of medicine. 2015;47(2):104.
17. 17. Kılıçaslan F. The effects of cigarette smoking on the Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio. 2015.
18. 18. Ciampricotti R, El Gamal M. Vasospastic coronary occlusion associated with a myocardial bridge. Catheterization and cardiovascular diagnosis. 1988;14(2):118-20.
19. 19. Masuda T, Ishikawa Y, Akasaka Y, et al. The effect of myocardial bridging of the coronary artery on vasoactive agents and atherosclerosis localization. The Journal of pathology. 2001;193(3):408-14.
20. 20. Hostiuc S, Curca G, Dermengiu D, et al. Morphological changes associated with hemodynamically significant myocardial bridges in sudden cardiac death. The Thoracic and cardiovascular surgeon. 2011;59(07):406-10.