Objectives: Cardiac syndrome X (CSX) is a condition characterized by exercise-induced chest pain that occurs considering a normal coronary angiogram. We aimed to investigate the total serum antioxidant capacity (TAC) and biventricular global functions using echocardiography in patients with CSX.
Patients and methods: The study population included 55 patients with typical anginal symptoms and a positive exercise stress test, or ischemia in myocardial perfusion scintigraphy and normal coronary arteries detected angiographically, and 49 healthy volunteers with atypical chest pain and a negative stress test. TAC was assessed from blood samples. Transthoracic echocardiography was performed for the entire study population. The Tei index was calculated using the formula IVCT+IVRT/ET.
Results: TAC was found to be significantly lower in the CSX group compared with the control group (0.70±0.37 vs. 1.5±0.30, respectively, P<0.001). The Tei index was significantly higher in patients with CSX than the control group (0.60±0.18 vs. 0.42±0.12, respectively, P<0.001).There was a significant and inverse relationship between TAC and the Tei index (r=-0.41, P<0.001). When we divided the study population according to the normal range of TAC into the decreased TAC group (<1.30 mmol/l), the normal TAC group (1.30-1.77 mmol/l), and the increased TAC group (>1.77 mmol/l), it was found that the Tei index was higher in the decreased TAC group compared with the other groups (0.66±0.18 vs. 0.49±0.10 and 0.46±0.13 mmol/l, P<0.001, respectively).
Conclusion: Our study suggested that TAC was significantly decreased in CSX patients and decreased antioxidant levels were related to impaired Tei index in echocardiography in patients with microvascular angina.