Introduction: Low-level electrocardiographic changes from depolarization wavefront may accompany acute myocardial ischemia. The purpose of this study was to assess the changes of microvolt amplitude intra-QRS potentials induced by elective percutaneous coronary interventions (PCI).; Methods: Fifty-seven patients with balloon inflation periods ranging from 3.1 to 7.3 minutes (4.9 +/- 0.7 min) were studied. Nine leads continuous high-resolution ECG before and during PCI were recorded and signal-averaged. Abnormal intra-QRS at microvolt level (mu AIQP) were obtained using a signal modeling approach. mu AIQP, R-wave amplitude and QRS duration were measured in the processed ECG during baseline and PCI episodes.; Results: The mean mu AIQP amplitude significantly decreased for each of the standard 12 leads at the PCI event respect to baseline. Left anterior descending artery (LAD) occlusion resulted in a decrease mu AIQP in both the precordial leads and the limb leads, while right coronary (RCA) and left circumflex (LCx) arteries occlusions mainly affected limb leads. R-wave amplitude increased during PCI in RCA and LCx groups in lead III but decreased in the precordial leads, while the amplitude decreased in the LAD group in lead III. The average duration of the QRS augmented in groups RCA and LCx but not in the LAD group.; Conclusions: Abnormal intra-QRS potentials at the level of mu V provide an excellent tool to characterize the very-low amplitude fragmentation of the QRS complex and its changes due to ischemic injuries. mu AIQP shows promise as a new ECG index to measure electrophysiologic changes associated with acute myocardial ischemia. (c) 2014 The Authors. Published by Elsevier Inc.
Gomis, P.; Caminal, P.; Vallverdu, M.; Warren, S.; Stein, P.; Wagner, G. Journal of electrocardiology Vol. 45, num. 1, p. 82-89 DOI: 10.1016/j.jelectrocard.2011.08.013 Data de publicació: 2012-01 Article en revista