Gomis Pedro, Caminal Pere
Department ESAII, EUETIB, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain; CIBER de Bioingeniería Biomateriales y Nanomedicina (CIBER-BBN), Spain.
Department ESAII, EUETIB, Universitat Politècnica de Catalunya (UPC), Barcelona, Spain; CIBER de Bioingeniería Biomateriales y Nanomedicina (CIBER-BBN), Spain.
J Electrocardiol. 2014 Jul-Aug;47(4):512-9. doi: 10.1016/j.jelectrocard.2014.04.014. Epub 2014 Apr 26.
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).
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 (μAIQP) were obtained using a signal modeling approach. μAIQP, R-wave amplitude and QRS duration were measured in the processed ECG during baseline and PCI episodes.
The mean μAIQP 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 μAIQP 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.
Abnormal intra-QRS potentials at the level of μV provide an excellent tool to characterize the very-low amplitude fragmentation of the QRS complex and its changes due to ischemic injuries. μAIQP shows promise as a new ECG index to measure electrophysiologic changes associated with acute myocardial ischemia.
去极化波前的低水平心电图变化可能伴随急性心肌缺血。本研究的目的是评估选择性经皮冠状动脉介入治疗（PCI）引起的QRS波内微伏级振幅电位的变化。
研究了57例球囊扩张时间为3.1至7.3分钟（4.9±0.7分钟）的患者。记录并信号平均了PCI前和PCI期间9个导联的连续高分辨率心电图。使用信号建模方法获得微伏级的QRS波内异常（μAIQP）。在基线和PCI期间，在处理后的心电图中测量μAIQP、R波振幅和QRS持续时间。
与基线相比，在PCI事件中，标准12个导联中的每一个导联的平均μAIQP振幅均显著降低。左前降支（LAD）闭塞导致胸前导联和肢体导联的μAIQP降低，而右冠状动脉（RCA）和左旋支（LCx）动脉闭塞主要影响肢体导联。在RCA和LCx组中，III导联的R波振幅在PCI期间增加，但在胸前导联中降低，而在LAD组中，III导联的振幅降低。RCA和LCx组的QRS平均持续时间增加，但LAD组未增加。
微伏级的QRS波内异常电位为表征QRS波群极低振幅碎裂及其因缺血损伤引起的变化提供了一个极好的工具。μAIQP有望作为一种新的心电图指标来测量与急性心肌缺血相关的电生理变化。
