Turk Kardiyol Dern Ars. 2018; 46(6): 446-454 | DOI: 10.5543/tkda.2018.76967
Increased myocardial energy expenditure in cardiac syndrome X: More work, more pain
Mehmet Serkan Çetin1
, Elif Hande Özcan Çetin2
, Uğur Canpolat3
, Mehmet Akif Erdöl2
, Selahattin Aydın4
, Özlem Özcan Çelebi2
, Ahmet Temizhan2
, Yeşim Akın2
, Omaç Tüfekçioğlu2
, Dursun Aras2
, Serkan Topaloğlu2
, Sinan Aydoğdu21
Department of Cardiology, Bülent Ecevit University Faculty of Medicine, Zonguldak, Turkey2
Department of Cardiology, Türkiye Yüksek İhtisas Training and Research Hospital, Ankara, Turkey3
Department of Cardiology, Hacettepe University Faculty of Medicine, Ankara, Turkey4
Department of Cardiology, Balıkesir Atatürk State Hospital, Balıkesir, Turkey
OBJECTIVE The aim of this study was to assess the myocardial energy expenditure (MEE) in patients with cardiac syndrome X (CSX) and to examine its association with exercise electrocardiogram (ECG) parameters.
METHODS A total of 99 patients who underwent coronary angiography and who were diagnosed as having normal coronary arteries were included. The patients were divided into 2 groups based on symptoms and exercise ECG parameters: 56 CSX patients and 43 control patients with a negative stress test. MEE was calculated using transthoracic echocardiography-derived parameters: circumferential end-systolic stress, left ventricular ejection time, and stroke volume.
RESULTS In patients with CSX, the MEE at rest was 28% higher in than the control group (89.2±36.3 vs. 69.8±17.2 cal/minute). Correlation analysis revealed a moderately negative correlation between MEE and the Duke treadmill score (DTS) (β: -0.456; p<0.001). Receiver operating characteristic analysis with a cut-off value of 74.6 cal/minute for MEE had a sensitivity of 78.1% and a specificity of 75.3% for the prediction of CSX (area under the curve: 0.872; p<0.001). An extra 1 calorie spent per minute at rest increased the likelihood of CSX by about 86% (odds ratio: 1.863).
CONCLUSION This study demonstrated that MEE was greater in CSX patients compared with a control group. Increased MEE was determined to be an independent predictor of CSX. DTS was inversely correlated with MEE. Increased MEE may have a crucial role in CSX pathophysiology.
Duke score, cardiac syndrome X; myocardial energy expenditure.
How to cite this article
Mehmet Serkan Çetin, Elif Hande Özcan Çetin, Uğur Canpolat, Mehmet Akif Erdöl, Selahattin Aydın, Özlem Özcan Çelebi, Ahmet Temizhan, Yeşim Akın, Omaç Tüfekçioğlu, Dursun Aras, Serkan Topaloğlu, Sinan Aydoğdu. Increased myocardial energy expenditure in cardiac syndrome X: More work, more pain. Turk Kardiyol Dern Ars. 2018; 46(6): 446-454
Corresponding Author: Elif Hande Özcan Çetin, Türkiye