Pizzetti G, Montorfano M, Belotti G, Margonato A, Ballarotto C, Chierchia S L
Department of Cardiology, Istituto Scientifico H.S.Raffaele, Milano, Italy.
Eur Heart J. 1998 Mar;19(3):420-8. doi: 10.1053/euhj.1997.0772.
We investigated the ability of T-wave pseudonormalization and ST-segment elevation, which are demonstrated in infarct-related leads during submaximal exercise testing, to predict late recovery of contractile function.
We studied 88 consecutive patients (73 males, mean age 59 +/- 8 years) with anterior infarction, persistent T-wave inversion and a documented lesion of the proximal segment of the left anterior descending coronary artery. They all underwent 2D-echocardiography on admission, 4 weeks as well as 6 months after myocardial infarction to evaluate the dysfunction score and the ejection fraction. Submaximal (75% of maximal predicted heart rate) exercise testing was performed in 80 patients 2 weeks after myocardial infarction following discontinuation of treatment.
During exercise testing, 59 of the 88 patients showing negative T-waves on the resting electrocardiogram exhibited pseudonormalization (group A) in at least three adjacent precordial leads, whilst 29 (group B) did not. Patients of group A more frequently exhibited an early creatine kinase peak (41% vs 24%, P < 0.05) and residual angiographic perfusion (97% vs 69%, P < 0.05). The dysfunction score did not change in group B (from 19 +/- 7 to 22 +/- 4), but decreased in group A (from 18 +/- 4 to 11 +/- 6 P < 0.05). The ejection fraction was similar in the two groups on admission (group A: 48 +/- 7%, group B: 45 +/- 10%), but was significantly different at 4-week (52 +/- 99 vs 42 +/- 11%, P < 0.05) and 6-month follow-up (58 +/- 9 vs 44 +/- 10%, P < 0.01). The concomitant presence of ST-segment elevation and T-wave normalization showed the highest positive predictive value for left ventricular function recovery (100%).
T-wave normalization induced by submaximal exercise test is frequently associated with residual perfusion to the infarct area and predicts progressive improvement in regional wall motion, especially if associated with ST-segment elevation. Therefore, these electrocardiographic findings may be used as easily obtainable markers of residual viability that predict late recovery in contractile function.
我们研究了在次极量运动试验中梗死相关导联出现的T波假性正常化和ST段抬高预测收缩功能晚期恢复的能力。
我们连续研究了88例（73例男性，平均年龄59±8岁）前壁心肌梗死、持续性T波倒置且记录到左前降支近端病变的患者。他们均在入院时、心肌梗死后4周以及6个月接受二维超声心动图检查，以评估功能障碍评分和射血分数。80例患者在心肌梗死后2周停止治疗后进行次极量（最大预测心率的75%）运动试验。
在运动试验期间，静息心电图显示T波倒置的88例患者中，59例（A组）在至少三个相邻胸前导联出现假性正常化，而29例（B组）未出现。A组患者更频繁地出现肌酸激酶早期峰值（41%对24%，P<0.05）和残余血管造影灌注（97%对69%，P<0.05）。B组功能障碍评分未改变（从19±7到22±4），但A组降低（从18±4到11±6，P<0.05）。两组入院时射血分数相似（A组：48±7%，B组：45±10%），但在4周（52±9对42±11%，P<0.05）和6个月随访时（58±9对44±10%，P<0.01）有显著差异。ST段抬高和T波正常化同时出现对左心室功能恢复显示出最高的阳性预测值（100%）。
次极量运动试验诱导的T波正常化常与梗死区域的残余灌注相关，并预测局部室壁运动的逐渐改善，尤其是与ST段抬高相关时。因此，这些心电图表现可作为易于获得的残余存活心肌标志物，预测收缩功能的晚期恢复。
