Unmasking Syndrome X

Abstract

Background. The differential diagnosis of chest pain in women is complex, ranging from atypical angina to chest pain in the absence of coronary artery disease (i.e., Syndrome X). The mechanism of these conditions remains unexplained. The purpose of this study was to examine coronary blood flow based on a new angiographic technique. Methods. Patients with chest pain were enrolled. In the new technique, as the contrast injection stopped, the blood in white color moved in and displaced the black contrast. Characteristics of blood flow could be observed and classified by type and time. The duration of the arterial phase was calculated and compared with the control. Results. Sixty patients were enrolled. Ten patients with normal coronary arteries and ventricular function; without chest pain served as controls. In the control group, the duration of the arterial phase in the RCA was 1.76 sec, while it was 3.76 sec for the syndrome X group (p<0.05). From the mMID segment to the distal segment, syndrome X patients had a much longer delay compared to control subjects (0.81 vs. 0.26 sec) (p<0.05). From the distal segment (bDIS) to the origin of the PDA, syndrome X patients had an average duration of 0.81 sec compared to 0.40 sec in controls (p<0.05). The largest difference was the period of time when the contrast left the PDA until flushed from the distal vasculature, which was 1.66 sec and 0.40 sec in syndrome X vs. control. Syndrome X patients with prolonged myocardial phase (1.89 sec) had dense and prolonged contrast retention at the myocardium. Conclusions. In patients with syndrome X, the prolonged arterial phase deprived the myocardium of highly oxygenated blood and triggered ischemia. This new imaging method allows for a better understanding of the mechanism of ischemia in Syndrome X patients.