Narain V S, Bhargava B, Chandra N, Puri V K, Hasan M
Department of Cardiology, K.G.'s Medical College, Lucknow.
Indian Heart J. 1994 Jul-Aug;46(4):149-52.
Aortic and coronary sinus platelet aggregation, thromboxane A2 (TXA2) and prostacyclin (PG12) levels were studied in fourteen patients of stable angina (SA), six of vasopastic angina (VA) and six control subjects (C). Patients of SA were studied at rest and during incremental atrial pacing and patients with VA were studied at rest and during various stages of vasospasm. Platelet aggregation was studied with different working concentrations of ADP, epinephrine and collagen. TX A2 and PGI2 concentrations were estimated by measuring levels of their stable metabolites viz. thromboxane B2 (TXB2) and 6-keto prostaglandin F1 alpha (PGF1 alpha) respectively. Platelet aggregation was increased in SA and VA patients (p < 0.01) and further increase was seen during vasospasm (p < 0.001). However, it failed to increase on incremental atrial pacing. Similarly, TXB2 and PGF1 alpha levels were raised in SA and VA patients. While TXB2 further increased during vasospasm but not during atrial pacing. PGF1 infinity failed to rise with either. Thus platelets are in an activated state in SA and VA. This activated state is a cause and not an effect in SA and VA. An imbalance in the levels of TXA2 and PG12 could account for the vasospasm.
对14例稳定型心绞痛（SA）患者、6例变异性心绞痛（VA）患者和6例对照者（C）的主动脉和冠状窦血小板聚集、血栓素A2（TXA2）和前列环素（PGI2）水平进行了研究。SA患者在静息状态和递增性心房起搏期间接受研究，VA患者在静息状态和血管痉挛的各个阶段接受研究。采用不同工作浓度的二磷酸腺苷（ADP）、肾上腺素和胶原研究血小板聚集情况。通过分别测量其稳定代谢产物血栓素B2（TXB2）和6-酮-前列腺素F1α（PGF1α）的水平来估计TXA2和PGI2的浓度。SA和VA患者的血小板聚集增加（p<0.01），在血管痉挛期间进一步增加（p<0.001）。然而，在递增性心房起搏期间血小板聚集未增加。同样，SA和VA患者的TXB2和PGF1α水平升高。虽然TXB2在血管痉挛期间进一步升高，但在心房起搏期间未升高。PGF1α在两种情况下均未升高。因此，SA和VA患者的血小板处于激活状态。这种激活状态在SA和VA中是原因而非结果。TXA2和PGI2水平的失衡可能是血管痉挛的原因。
