Kolev N S, Uzunov G K, Vlasakov V L, Tijaneva J G
Acta Cardiol. 1981;36(4):263-73.
The effect of various alterations in preload, afterload and inotropic state of the left ventricle on the first derivative of apex cardiogram (dA/dt) was studied in the anesthetized dogs, in an attempt to clarify some of the determinants of the negative peak of dA/dt and isovolumetric relaxation time. First derivative of apex cardiogram was recorded simultaneously with left ventricular pressure, conventional left apex cardiogram, first derivative of left ventricular pressure, electrocardiogram and phonocardiogram. Both dA/dt and dP/dt curves represent similarity in contour and were found to occur nearly simultaneously. This close relationship was preserved during various acutely hemodynamic changes. Maximum negative dA/dt and isovolumic relaxation period was closely related to the level of afterload. Large rapid augmentation of mean aortic pressure did results in statistically significant increase of negative dA/dt and shortening of isovolumic relaxation time, where reduction of after load had an opposite effect. Another interventions, which acutely augment min dA/dt was nitroprusside and isoprenalin. It is concluded, that negative peak dA/dt under some conditions provides a reliable noninvasive index for assessing myocardial relaxation.
在麻醉犬身上研究了左心室前负荷、后负荷和心肌收缩力状态的各种改变对心尖搏动图一阶导数（dA/dt）的影响，以阐明dA/dt负向峰值和等容舒张时间的一些决定因素。心尖搏动图一阶导数与左心室压力、传统的心尖搏动图、左心室压力一阶导数、心电图和心音图同时记录。dA/dt和dP/dt曲线在轮廓上相似，且几乎同时出现。在各种急性血流动力学变化过程中，这种密切关系得以保持。最大负向dA/dt和等容舒张期与后负荷水平密切相关。平均主动脉压的大幅快速升高确实导致负向dA/dt有统计学意义的增加和等容舒张时间缩短，而后负荷降低则有相反的效果。另一种能急性增加最小dA/dt的干预措施是硝普钠和异丙肾上腺素。得出的结论是，在某些情况下，负向峰值dA/dt为评估心肌舒张提供了一个可靠的非侵入性指标。
