ST-T alternans and myocardial ischemia

Previous studies using intracoronary electrocardiography have demonstrated that ST-T alternans can develop during standard balloon coronary angioplast y. Total occlusion with a large amount of myocardium in jeopardy is the pos tulated prerequisite. In this study, the authors used perfusion balloons in stead of standard balloons, so coronary perfusion was maintained and ischem ia was minimized. Fourteen patients with standard balloon technique and 11 patients with perfusion balloon technique were studied. The ST segment was less elevated during perfusion angioplasty (0.15 +/- 0.05 mV vs 1.04 +/- 0. 19 mV, p < 0.0013. There were six (43%) patients with ST-T alternans with s tandard balloon technique compared with none in the perfusion balloon group (p < 0.001). In this study, the authors found that there was less ischemia , less ST segment elevation, and lack of ST-T alternans on the intracoronar y electrocardiogram during perfusion balloon angioplasty. These findings su pport the postulate that a large amount of ischemic myocardium is a prerequ isite for ST-T alternans.