OBJECTIVETo assess the effect and safety of intra-coronary administration of anisodamine on "slow-reflow" phenomenon of infarct related artery (IRA) following primary percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI).

METHODSTwenty-five patients with slow-reflow phenomenon screened out from 153 AMI patient with post-PCI reflow IRA were enrolled. They were 17 males and 8 females; aged (62.3 +/- 9.3) years; 10 with focal artery at left anterior descendens, 5 in circumflux and 10 in right coronary artery; PCI was successfully performed on them about 7.11 +/- 2.31 h after the onset of angina pectoris and the post-operation mean TIMI flow was 1.75 +/- 0.42 grade. Nitroglycerin (200 microg) was injected into coronary previously for confirming the slow-reflow phenomenon as control, then the injection of anisodamine 500 microg 10 min later. Coronary arteriography (CAG) was performed at the 1 st, 3 rd and 10 th min after the medication. Gibson's TIMI frame count method and quantitative computer angiography (QCA) system was used to quantitatively detect the frames of blood flow and the diameter of arterial lumen at different time points after nitroglycerin or anisodamine administration. Hemodynamics and changes of electrocardiogram were determined.

RESULTS(1) No significant change in frames of blood flow was found between before and 1 min after intra-coronary administration of nitroglycerin (82.79 +/- 9.30 frames vs 78.43 +/- 9.37 frames, P >0. 05) after operation; but 1, 3 and 10 min after injection of anisodamine, it was decreased 46.25 +/- 4.55, 44.52 +/- 4.52 and 43.09 +/- 4.18, respectively, all P <0. 01, and the average coronary blood flow increased from TIMI grade 1.75 +/- 0.42 to grade 2.70 +/- 0.45 (t = 0. 34, P < 0.05). (2) The diameter of middle segment of reopened coronary artery slightly increased from 3.2 +/- 0.3 mm to 3.3 +/- 0.4 mm 3 min after anisodamine injection, but without statistical significance (P >0. 05). (3) Successive monitoring at 10 min after anisodamine injection showed that all the parameters, including intra-coronary pressure, peripheral blood pressure, P-R interval, Q-T interval and QRS duration were not changed significantly (P > 0.05), only the heart rate increased for 15-19 beats/min, but did not induce tachycardia or other malignant arrhythmia.

CONCLUSIONIntra-coronary administration of anisodamine 500 microg could improve the post-PCI slow-reflow phenomenon, it is safe and convenient, and may be taken as an effective approach for treatment of the illness.