Abstract
Although several diagnostic criteria focusing on variations in the ST-T segment during exercise and in the recovery phase have been proposed to obviate this shortcoming, no satisfactory method has yet been devised. The aim of the present study was to investigate the degree of coronary artery disease reflected by ST-T changes seen in the recovery phase of treadmill exercise electrocardiography (ECG). The subjects were 215 men (mean age±standard deviation : 56±10 years) with chest pain syndrome who underwent both treadmill exercise ECG and coronary angiography. The ST-T changes seen at various time intervals after exercise stress were classified into four groups : unchanged (group A ; 91 patients) ; improved during the recovery phase (group B; 40 patients) ; worsened during the recovery phase (group C ; 54 patients) ; and appeared only during the recovery phase (group D; 30 patients). The ECG results were then compared with the angiography findings. Multivariate analysis identified the Gensini score as an independent factor associated with worsening of ST-T changes in the post-exercise recovery period, and positive acetylcholine injection test findings as an independent factor associated with the appearance of ST-T changes only in the recovery phase. Multi-vessel disease was diagnosed with a sensitivity of 58% and a specificity of 84% in patients whose ST-T changes worsened during the recovery phase. Coronary spasm was diagnosed with a sensitivity of 59% and a specificity of 96% when the appearance of ST-T changes only during the recovery phase was used. These results indicate that worsening of ST-T changes during the recovery phase suggests the presence of severe coronary artery disease, whereas the appearance of ST-T changes only during the recovery phase suggests the presence of coronary spasm.
