Yanagisawa N, Honda M, Watanabe H, Nakamura F, Higuchi Y, Wada T
J Cardiogr. 1981 Sep;11(3):881-9.
On the long-axis view of tomographic echocardiography, the aorto-septal angle (AS angle) of cases with straight back syndrome was wide and was thought to be due to clockwise rotation of the heart rather than right ventricular enlargement. In the present study, the AS angle of 21 cases with counterclockwise rotation of the heart (CCW) was measured on the long-axis view. The counterclockwise rotation of the heart defined here as having a shift of the transitional zone to the right with a small septal q wave at V2 and/or V3 to V6 in the precordial leads. Every case of CCW was found to have an absence of main pulmonary artery shadow on posteroanterior projection of the chest X-ray film. The control groups consisted of 40 normal individuals and 14 cases of straight back syndrome. The AS angle of normals ranged from 120 degrees to 158 degrees with a mean of 142 degrees. The AS angle of the latter varied from 140 degrees to 165 degrees with a mean of 150 degrees. On the other hand, the 21 cases with CCW showed the AS angle from 80 degrees to 129 degrees with a mean of 102 degrees. Since every CCW showed dilatation and/or elongation of the thoracic aorta on their radiographs, the narrowed AS angle was probably due to rightward twist of left ventricular outflow tract with some posterior retraction of the aorta. This causes the rightward twist of upper portion of the septum and results in a shift of the transitional zone to the right with a small q wave at V2 and/or V3 to V6 in the precordial leads. When normally visible main pulmonary artery shadow disappears on the postero-anterior chest X-ray film, the CCW is indicated radiographically. The narrowing of the AS angles on the long-axis views of tomographic echocardiography also indicates the CCW and correlate with both electrocardiographic and radiographic findings of CCW. The cause of CCW has not been well delineated. In the previous paper, we have suggested that the left ventricular overloading has little influence in producing CCW. In the present study, the 21 cases with CCW did not show either the left ventricular hypertrophy or the dilatation on their echocardiograms further supporting our hypothesis.
在断层超声心动图的长轴视图上，直背综合征患者的主动脉-室间隔角（AS角）较宽，被认为是心脏顺时针旋转而非右心室扩大所致。在本研究中，在长轴视图上测量了21例心脏逆时针旋转（CCW）患者的AS角。这里将心脏逆时针旋转定义为过渡区向右移位，胸前导联V2和/或V3至V6出现小的间隔q波。发现每例CCW患者在胸部X线后前位片上均无主肺动脉阴影。对照组包括40名正常个体和14例直背综合征患者。正常组的AS角范围为120度至158度，平均为142度。后者的AS角在140度至165度之间变化，平均为150度。另一方面，21例CCW患者的AS角在80度至129度之间，平均为102度。由于每例CCW患者的X线片上均显示胸主动脉扩张和/或延长，AS角变窄可能是由于左心室流出道向右扭曲以及主动脉向后稍有回缩所致。这导致室间隔上部向右扭曲，并导致过渡区向右移位，胸前导联V2和/或V3至V6出现小q波。当在胸部X线后前位片上正常可见的主肺动脉阴影消失时，X线片提示CCW。断层超声心动图长轴视图上AS角变窄也提示CCW，且与CCW的心电图和X线表现相关。CCW的病因尚未明确。在之前的论文中，我们曾提出左心室负荷过重对产生CCW影响不大。在本研究中，21例CCW患者的超声心动图均未显示左心室肥厚或扩张，进一步支持了我们的假设。
