Suzuki A, Hirai M, Hayashi H, Tomita Y, Ichihara Y, Adachi M, Oguchi S, Takatsu F
First Department of Internal Medicine, University of Nagoya School of Medicine, Japan.
Eur Heart J. 1993 Aug;14(8):1094-101. doi: 10.1093/eurheartj/14.8.1094.
The clinical value of QRST isointegral maps (I-maps) for the detection of myocardial infarction (MI) in the presence of left bundle branch block (LBBB) was investigated. We recorded I-maps during sinus rhythm and right ventricular (RV) pacing, which simulated LBBB, in 62 patients with MI (42 patients had at least one akinetic segment and the remaining 20 patients had only hypokinesis or normal contraction) and 26 patients without MI. An abnormal decrease in the QRST value of the I-map was assessed by the difference map (D-map), which indicated a '-2SD area', where the QRST integral value was less than the lower limit of the normal range (mean -2SD) calculated from 608 normal individuals. The I-maps recorded during the two activation sequences were similar to each other in patients with and without MI (r = 0.87 and 0.92, respectively). The '-2SD area' was located over the left anterior chest in patients with an anterior MI and over the lower torso in patients with an inferior MI during each activation sequence. We were able to diagnose MI during simulated LBBB with a sensitivity of 84%, a specificity of 81% and a diagnostic accuracy of 83% when we used the criterion that MI is present if the sum of QRST integral values below the normal range (sigma DM) exceeds 100 mV.ms. We were able to diagnose an akinesis with a sensitivity of 81%, a specificity of 85% and a diagnostic accuracy of 83% when we used the criterion that akinesis is present if sigma DM exceeds 500 mV.ms during simulated LBBB.(ABSTRACT TRUNCATED AT 250 WORDS)
研究了QRST等积分图（I图）在存在左束支传导阻滞（LBBB）时检测心肌梗死（MI）的临床价值。我们记录了62例心肌梗死患者（42例至少有一个运动减弱节段，其余20例仅有运动减弱或正常收缩）和26例无心肌梗死患者在窦性心律和右心室（RV）起搏（模拟LBBB）期间的I图。通过差值图（D图）评估I图中QRST值的异常降低，D图显示一个“-2SD区域”，其中QRST积分值低于由608名正常个体计算出的正常范围下限（平均-2SD）。有心肌梗死和无心肌梗死患者在两种激动顺序期间记录的I图彼此相似（分别为r = 0.87和0.92）。在每次激动顺序期间，前壁心肌梗死患者的“-2SD区域”位于左前胸，下壁心肌梗死患者的位于下腹部。当我们使用QRST积分值低于正常范围之和（σDM）超过100 mV.ms则存在心肌梗死这一标准时，我们能够在模拟LBBB期间诊断心肌梗死，敏感性为84%，特异性为81%，诊断准确性为83%。当我们使用在模拟LBBB期间σDM超过500 mV.ms则存在运动减弱这一标准时，我们能够诊断运动减弱，敏感性为81%，特异性为85%，诊断准确性为83%。（摘要截断于250字）
