Tsunakawa H, Nishiyama G, Kusahana Y, Harumi K
Division of Cardiology, Showa University Fujigaoka Hospital, Yokohama, Japan.
J Am Coll Cardiol. 1989 Nov 15;14(6):1530-6. doi: 10.1016/0735-1097(89)90393-8.
The QRST area map has been related to susceptibility to ventricular tachyarrhythmias because it reflects the disparity of ventricular recovery properties. However, the clinical value of the nondipolarity of the QRST area map, a marker of nonuniform ventricular repolarization, has not been fully studied in myocardial infarction. The nondipolarity of the QRST area map (residue), the ratio of minimized deviation by an optimal dipole to the total measured potentials, was quantitatively studied in relation to susceptibility to ventricular tachycardia after myocardial infarction. The residue of the QRST area map was higher in 59 patients with myocardial infarction than in 44 normal subjects (25.0 +/- 9.0 versus 17.8 +/- 3.3%, p less than 0.01). Seventeen patients with ventricular tachycardia in the chronic phase (greater than 10 days) of myocardial infarction showed higher residue in their QRST area map (34.5 +/- 10.3%) than that in 29 patients without ventricular tachycardia throughout the study (22.7 +/- 6.7%) or that in 13 patients with ventricular tachycardia only in the acute phase (21.2 +/- 7.5%). QRST area maps with a residue greater than or equal to 25% (mean + 2 SD of normal subjects) identified patients with ventricular tachycardia in the chronic phase of myocardial infarction with a sensitivity of 82% and a specificity of 71%. These results suggest that quantitative assessment of the nondipolarity of the QRST area map is clinically useful for identifying susceptibility to ventricular tachycardia in the chronic phase of myocardial infarction.
QRST面积图与室性快速心律失常的易感性相关，因为它反映了心室恢复特性的差异。然而，QRST面积图的非双极性（心室复极不均匀的一个标志）在心肌梗死中的临床价值尚未得到充分研究。QRST面积图的非双极性（残差），即最优偶极子最小化偏差与总测量电位的比值，已针对心肌梗死后室性心动过速的易感性进行了定量研究。59例心肌梗死患者的QRST面积图残差高于44例正常受试者（分别为25.0±9.0%和17.8±3.3%，p<0.01）。17例心肌梗死慢性期（大于10天）发生室性心动过速的患者，其QRST面积图残差（34.5±10.3%）高于整个研究过程中29例未发生室性心动过速的患者（22.7±6.7%）或13例仅在急性期发生室性心动过速的患者（21.2±7.5%）。残差大于或等于25%（正常受试者均值+2标准差）的QRST面积图识别心肌梗死慢性期室性心动过速患者的灵敏度为82%，特异度为71%。这些结果表明，对QRST面积图非双极性进行定量评估在临床上有助于识别心肌梗死慢性期室性心动过速的易感性。
