Beker B, Vered Z, Bloom N V, Ohad D, Battler A, Di Segni E
Neufeld Cardiac Research Institute, Sackler School of Medicine, Tel Aviv University, Tel Hashomer, Israel.
J Am Soc Echocardiogr. 1994 Jul-Aug;7(4):381-7. doi: 10.1016/s0894-7317(14)80196-x.
Stress echocardiography is used increasingly in the evaluation of coronary artery disease. The echocardiographic evaluation of ischemia is based on stress-induced changes in wall motion and wall thickening of the ischemic segments. Studies have demonstrated that left ventricular volumetric changes may induce changes in wall thickness. The aim of the study was to evaluate whether significant changes in ventricular volume, wall thickness, and wall thickening occur during stress echocardiography with atrial pacing. Seven German Landrace female pigs were studied 4 weeks after the induction of a small myocardial infarction. Echocardiographic measurements were conducted in noninfarcted segments on the short-axis view at baseline and during atrial pacing at 120, 150, and 180 beats/min. End-diastolic circumferential area decreased from 12.3 +/- 2.0 cm2 at baseline to 8.9 +/- 1.9 cm2 at 180 beats/min of atrial pacing (p < 0.01). Mean wall thickness (interventricular septal plus posterior wall thickness divided by 2) increased markedly and progressively from 6.7 +/- 0.6 mm at baseline to 9.8 +/- 1.0 mm at 180 beats/min (p < 0.01). The increase in wall thickness correlated inversely with end-diastolic area (r = -0.57; p < 0.01). Percent systolic thickening decreased from 38.9 +/- 12.0 at baseline to 14.9 +/- 7.4 at 180 beats/min of atrial pacing (p < 0.01). The decrease in percent wall thickening correlated with the increase in wall thickness (r = -0.71; p < 0.01). In conclusion, this study shows that a marked increase in wall thickness (pseudohypertrophy) and decrease in percent systolic thickening are observed during rapid atrial pacing in normal myocardium and do not indicate stress-induced left ventricular dysfunction.
负荷超声心动图在冠状动脉疾病评估中的应用日益广泛。缺血的超声心动图评估基于缺血节段室壁运动和室壁增厚的负荷诱导变化。研究表明，左心室容积变化可能会引起室壁厚度改变。本研究的目的是评估在心房起搏负荷超声心动图检查期间，心室容积、室壁厚度和室壁增厚是否会发生显著变化。对7只德国长白母猪在诱发小面积心肌梗死后4周进行研究。在短轴视图上对非梗死节段进行超声心动图测量，测量在基线时以及心房起搏频率为120、150和180次/分钟时进行。舒张末期圆周面积从基线时的12.3±2.0平方厘米降至心房起搏频率为180次/分钟时的8.9±1.9平方厘米（p<0.01）。平均室壁厚度（室间隔加后壁厚度除以2）从基线时的6.7±0.6毫米显著且逐步增加至180次/分钟时的9.8±1.0毫米（p<0.01）。室壁厚度的增加与舒张末期面积呈负相关（r = -0.57；p<0.01）。收缩期增厚百分比从基线时的38.9±12.0降至心房起搏频率为180次/分钟时的14.9±7.4（p<0.01）。室壁增厚百分比的降低与室壁厚度的增加相关（r = -0.71；p<0.01）。总之，本研究表明，在正常心肌快速心房起搏期间，观察到室壁厚度显著增加（假性肥厚）和收缩期增厚百分比降低，这并不表明存在负荷诱导的左心室功能障碍。
