Evaluation of spatial heterogeneity of ventricular repolarization during coronary angioplasty

Percutaneous transluminal coronary angioplasty (PTCA) is a surgery procedure meant to open up blocked coronary arteries using balloon inflation. It also provides an excellent model to investigate the electrophysiological changes due to ischemia. In this work, we tested whether cardiac ischemia induced by prolonged balloon inflations might lead to changes in spatial heterogeneity of ventricular repolarization (SHVR), as measured by the V-index. With this aim, we analyzed the STAFF III dataset acquired during PTCA. Forty-subjects underwent a PTCA procedure with prolonged balloon inflations and the Vindex was estimated pre-, during and post- inflation. Two main results were found. First, V-index values during pre- and postinflation were not statistically significantly different (p > 0:05), suggesting a complete recovery after PTCA. Second, SHVR during the second part of the occlusion increased with respect to pre-inflation (median difference: 18.84 ms; p < 0:05). In conclusion, the V-index detected changes in SHVR due to the presence of early-stage cardiac ischemia.