负荷超声心动图检测暂时性心肌缺血的试验研究

Experimental Study of Stress Echocardiography Testing for Detecting Transient Myocardial Ischemia: Effects of Quantitative Dipyridamole Stress Test on the Heart of Dogs with Critical Coronary Stenosis

本文对３６只冠脉临界狭窄的杂种犬施行了定量潘生丁负荷超声心动图试验（ＤＳＥＴ）。动物分为３组：小剂量（潘生丁０．５ｍｇ／ｋｇ／４ｍｉｎ，静注），大剂量组（潘生丁１．０ｍｇ／８ｍｉｎ，静注）。和对照组（生理盐水１０ｍｌ／４ｍｉｎ，静注用药前、后连续记示两维超声心动图（２ＤＥ），平均主动脉压（ＭＡＰ）、心率（ＨＲ）、左室舒张末期压（ＬＶＥＤＰ）、远端冠脉压（ＤＣＰ）和节段性冠脉阻力（ＳＣＲ），并同时观察ＥＣＧ。结果显示：大剂量潘生丁注射后，ＭＡＰ从１３．４±０．８下降到１０．６±１．０ｋＰａ（Ｐ＜０．０５）；ＨＲ略有减低（Ｐ＜０．０５），ＤＣＰ明显减少（下降３０～３５％），ＣＢＦ减少超过４０％，２ＤＥ可检出局部室壁运动异常（ＲＷＭＡ）；而在小剂量组，ＤＣＰ仅下降１０～２０％，ＣＢＦ增加１０～２０％，而ＨＲ无明显变化（Ｐ＞０．０５）。结论：冠脉临界狭窄时，由于ＣＢＦ和ＳＣＲ对定量潘生丁试验呈双向变化，所以，小剂量潘生丁不能诱发明显的ＲＷＭＡ，而大剂量潘生丁注射后，２ＤＥ即可检出明显的一过性心肌缺血。

The quantitative dipyridamole stress echocardiography test (DSET) was performed in 36 mongrel dogs with critical coronary stenosis. The dogs were separated into 3 groups according to the dose of diphyridamole: group of small dose dipyridamole (0. sing/kg/4min, i. v), group of high dose dipyridamole (1. 0mg/kg/8min, i. v ) and control (saline, 10ml/4min,i. v). Two-dimensional echocardiography (2DE) was monitored during dipyridamole infusion and mean aortic pressure (MAP),heart rate (HR ), left ventricular end-diastolic pressure (LVEDP ), distal coronary pressure (DCP ), segmental coronary resistance (SCR) and ECG were recorded simultaneously before and after dipyridamole infusion. Results showed that during the infusion of dipyridamole, the MAP fell from 13. 4±0. 8 to 10. 6±1. 0kpa (PRO. 05); HR decreased from 146 ± 8. 0 to 129± 11 veats/min (P<0. 05 ), DCP decreased by 30-35%, CBF decrreased by >40% and RWMA was detected by 2DE in the group with high dose of dipyridamole; but the DCP decreased by 10-20%, CBF increased to 10-20% and HR were unchanged (P>0. 05)in the group with small dose of dipyridumole. Conclusion: because there were dual responses of CBF and SCR of critical coronary artery stenosis quantitative of dipyridamole stress test, the RWMA was not induced by 2DE in small dose of dipuridamole but transient myocardial ischemia was significantly detected by 2DE in high dose of dipyridamole.