Objective To assess the MR characterization of coronary microembolization (CME)in an animal model as well as the evolution using MR cardiac cine,first-pass perfusion,and delay enhancement imaging.Methods Coronary microembolization models were established through intracoronary infusion of 120 000 microspheres (42 μm)into the left anterior descending artery in 1 1 pigs. Coronary angiography was performed at baseline and immediately after the injection of microspheres.MR imaging was carried out at baseline,6 hours,and 1 week after microembolization.Then,postmortem evaluation was performed using NBT and HE staining.Re-sults Coronary angiography after the injection of microspheres showed normal-appearing epicardial arteries in all animals.Coronary microembolization caused a significant decline in systolic wall thickening of the microembolized myocardial segments on cine MR ima-ges [from (42.6±2.0)% at baseline to (20.3±2.3)% at 6 hours and (31.5±2.1)% at 1 week after CME;P < 0.001 for both]. First-pass perfusion deficit was visualized at 6 hours after microembolization,and was less pronounced at 1 week.Hyperenhanced myocardium was found on delay enhancement MRI at 6 hours after microembolization in microembolized segments,but was not shown at 1 week. The microinfarcts were detectable microscopically through HE staining but invisible for the naked eye on gross NBT specimen.Con-clusion Coronary microembolization may cause a persistent decline in myocardial contraction and its MR characterization may vary with different stages.A combined use of different cardiac MRI techniques and follow-up examinations may be helpful for evaluating myocardial impairment due to coronary microembolization.

Objective To evaluate the application of multi-slice computed tomographic coronary angiography in diagnosis of chronic total occlusion (CTO) of coronary artery.Methods Six hundred and thirty eight patients were diagnosed as CTO disease with coronary angiography (CAG) from June 2011 to December 2012 in Zhongshan Hospital;236 of them received multi-slice computed tomographic coronary angiography in 60 days before.Results In total 708 vessels of the 236 patients,244 vessels were proved totally occluded,128 (52.5％) of which were located in left anterior descending artery,31 (12.7％) were located in left circumflex coronary artery and 85 (34.8％) located in right coronary artery.Multi-slice computed tomographic coronary angiography was superior to CAG in judgment of stump anatomy (64.3％ vs.52.5％,F =7.09,P =0.010),plaque calcification (40.2％ vs.26.2％,F =10.68,P =0.001) and distal vessel interpretability (93.9％ vs.74.6％,F =34.06,P ＜ 0.001).There was no significant difference in judging side branch,tortuosity and lesion length between multi-slice computed tomographic coronary angiography and CAG (all P ＞ 0.05).Conclusion Multi-slice computed tomographic coronary angiography provides more detailed anatomy information of CTO lesions and is of value in diagnosis and treatment of CTO lesions.

Objective To study the influence of different microembolism on left ventricular systolic synchronism in pigs by detecting the real-time dypyridamole stress contrast echocardiography (RT-MCE).Methods Eighteen miniature pigs were randomly divided into three groups and underwent microembolization injection procedure through the middle of anterior descending coronary artery with different numbers of microsphere injection,as:group A(dosage 50 thousands,3 pigs),group B (dosage 120 thousands,8 pigs) and group C (dosage 150 thousands,7 pigs).The peak values and the time-to-peak circumferential strain(Circ.Strain),radial velocity (Radial Vel.) and radial strain (Radial Strain) were obtained both at mitral valve level and papillary muscle level at left ventricle short axis views using two-dimensional speckle tracking imaging(STI)analyzed by Philips Q-Lab 8.1 workshop,respectively.Results No significant difference in the presence of contraction synchrony was observed using RT-MCE.The time-to-peak Circ.Strain of microembolism related segments were prolonged at 1 week after microembolism detecting with dypyridamole stress RT-MCE (P＜0.05,both intro-group and inter-group).While time-to-peak radial strain were extended since 6 hours after the intervention to 1 week after the procedure.Conclusions Dypyridamole stress RT-MCE can be used to measure the myocardial perfusion accurately.The elongation of time-to-peak circ.strain and radial strain were developed with time in microembolism related segments.

Coronary Occlusion ; therapy ; Coronary Vessels ; Humans ; Percutaneous Coronary Intervention

Objective To assess the effect of ultrasound contrast agent SonoVue on the dimensions and systolic function of left and right ventricle in pigs. Methods Sixteen pigs were randomly assigned to two groups. Intravenous injection of 1 ml of SonoVue were given in study group, and repeated 20 min later. The control group was given the same doses of saline. Before and after the administration of contrast agent, the end-diastolic dimension (LVEDD, RVEDD). end-systolic dimension ( LVESD, RVESD) and fractional shortening(LVFS,RVFS) of left and right ventricle were measured. The time to reach the extreme value of these parameters and the time to return to the baseline were recorded. Results There was no significant difference regarding the parameters at baseline between the two groups. After injection of SonoVue,RVEDD significantly increased from (25. 88 ± 1. 38) mm at baseline to its maximum of (33. 26 ± 0. 99)mm( P < 0. 05). Accordingly,RVFS significantly increased from (26. 90 ± 1. 92) % to (33. 92 ± 2. 53) % ( P <0. 05). Meanwhile,LVEDD remarkably decreased from (38.10 ± 1. 39)mm at baseline to its minimum of (26.25 ± 0. 65)mm( P <0. 05) and LVFS remarkably decreased from (36. 24 ± 1. 93) % to (29.13 ± 3.00) % ( P < 0. 05). There was no change in the control group after administration of the saline. When SonoVue was given repeatedly, the maximum RVEDD and RVFS was (29. 98 ± 1. 23) mm and (31. 09 + 1.90) % , respectively, which had less increase compared to the first time. Minimum LVEDD and LVFS was (31. 91 ± 1, 64)mm and (32. 17 ± 2. 31)%,respectively,with less decrease compared with which at first injection. It took (10. 15±0. 59) min for the right and left ventricle to reach the extreme value and (9.00± 0. 56) min to return to the baseline at the first injection. The time used for the right and left ventricle to reach its peak change and back to baseline after second injection of SonoVue were shorter [(8.73± 0.55) min and (6.89± 0.43) min, respectively,both P <0.05]. Conclusions Administration of SonoVue was associated with acute, transient dilation of right ventricle and compression of left ventricle. The influence of SonoVue on the right and left ventricle became less at it second injection.

Objective To observe the efficacy of antithrombotic treatment of acute ST-segment elevation myocardial infarction patients with failure primary percutaneous coronary intervention because of high thrombus burden,and its effect on elective percutaneous coronary intervention.Methods Eight acute ST-segment elevation myocardial infarction patients were enrolled,who suffered from failure of primary percutaneous coronary intervention because of high thrombus burden.Summarize the antithrombotic strategies in perioperative and postoperative period,the operative strategies and the follow-up coronary intervention were recorded and reviewed.Results All the patients were male and most of them had acute inferior myocardial infarction with right coronary occluded because of high thrombus burden.Four patients received thrombus aspiration and balloon dilation.One patient received thrombus aspiration and the other three patients did not receive coronary intervention.Tirofiban were given in perioperative period to all the patients.Low molecular weight heparin was given to 6 patients.Dual antiplatelet therapy was given to 6 patients (aspirin 100 mg/day plus clopidogrel 75 mg/day) and 1 patient required up-titration of aspirin to 200 mg/day.Coronary angiography were repeated (29.00 ± 23.25) days later,and the thrombus in the culprit vessels disappeared in two patients,and coronary stent implantation was performed in three patients.Conclusions The routine antithrombotic strategies play limited roles in thrombus clearance in acute ST segment elevation myocardial infarction patients with failure primary percutaneous coronary intervention because of high thrombus burden.The time for the thrombus to be totally organized and the timing of elective percutaneous coronary intervention are still uncertain and need to be further studied.

OBJECTIVE: To assess magnetic resonance imaging (MRI) features of coronary microembolization in a swine model induced by small-sized microemboli, which may cause microinfarcts invisible to the naked eye. MATERIALS AND METHODS: Eleven pigs underwent intracoronary injection of small-sized microspheres (42 microm) and catheter coronary angiography was obtained before and after microembolization. Cardiac MRI and measurement of cardiac troponin T (cTnT) were performed at baseline, 6 hours, and 1 week after microembolization. Postmortem evaluation was performed after completion of the imaging studies. RESULTS: Coronary angiography pre- and post-microembolization revealed normal epicardial coronary arteries. Systolic wall thickening of the microembolized regions decreased significantly from 42.6 +/- 2.0% at baseline to 20.3 +/- 2.3% at 6 hours and 31.5 +/- 2.1% at 1 week after coronary microembolization (p < 0.001 for both). First-pass perfusion defect was visualized at 6 hours but the extent was largely decreased at 1 week. Delayed contrast enhancement MRI (DE-MRI) demonstrated hyperenhancement within the target area at 6 hours but not at 1 week. The microinfarcts on gross specimen stained with nitrobluetetrazolium chloride were invisible to the naked eye and only detectable microscopically. Increased cTnT was observed at 6 hours and 1 week after microembolization. CONCLUSION: Coronary microembolization induced by a certain load of small-sized microemboli may result in microinfarcts invisible to the naked eye with normal epicardial coronary arteries. MRI features of myocardial impairment secondary to such microembolization include the decline in left ventricular function and myocardial perfusion at cine and first-pass perfusion imaging, and transient hyperenhancement at DE-MRI.
Animals ; Coronary Angiography/*methods ; Coronary Vessels/*pathology ; Disease Models, Animal ; Embolism/*pathology ; Female ; Heart/radiography ; Image Processing, Computer-Assisted ; Magnetic Resonance Imaging/*methods ; Microspheres ; Myocardial Contraction/physiology ; Myocardial Infarction/*pathology ; Myocardium/pathology ; Nitroblue Tetrazolium ; Staining and Labeling ; Swine ; Troponin T/blood ; Ventricular Function, Left

Coronary heart disease (CHD) treatment methods are changing rapidly, and new drugs are constantly entering the clinic. Antiplatelet drugs are the basis for the treatment of CHD, but there are currently no new drugs that can challenge the status of aspirin and P2Y

Objective Myocardial bridging is a congenital anomaly.However,little data is available for patients with myocardial bridging (MB) associated with acute myocardial infarction (AMI).The goals of this study are to evaluate characteristics of MB in patients with AMI.Methods From March 1999 to February 2006,137 patients with both MB and AMI,were identified by coronary angiography,including 117 men and 20 women with an average age of 60.77±12.01 years (range 30-83 years) were enrolled in the present study.Results There were 119 patients with MB at the middle segment of left anterior descending artery (LAD),15 patients at distal segment of LAD,2 patients at middle segment of left circumflex (LCX),and 1 at the proximal segment of the obtuse marginal branch (OM) of LCX.There are 36 patients with non-ST elevation acute myocardial infarction (NSTEAMI),38 patients with anterior ST elevation AMI (STEAMI),40 patients with inferior STEAMI and 23 patients with inferior-posterior STEAMI.Risk factors such as hypertension,diabetes,hyperlipidemia and smoking were not different among four groups.Patients with anterior AMI included 8 patients who showed no stenosis at the segment of MB.Conclusion Patients with MB and ST elevation AMI were mainly inferior AMI.MB might be one of the causes of AMI.

Objective: To investigate the safety and efficacy of rotational atherectomy in the interventional treatment of coronary chronic total occlusion lesions. Methods: In this retrospective study,a total of 31 consecutive patients with coronary chronic total occlusion(CTO) lesions underwent rotational atherectomy in our hospital from February 2004 to December 2016 were enrolled,and the clinical features were analyzed. Coronary atherectomy was performed if balloon failed to cross the CTO lesions or balloon could not be fully dilated in the CTO lesions after wire crossing. The definition of procedure success was defined as residual stenosis less than 20% after implantation of drug eluting stent and rotational atherectomy. After the procedure, the patients were followed up to observe major adverse cardiac and cerebral vascular events which including cardiogenic death, myocardial infarction, cerebrovascular accident, and target lesion revascularization. Results: The 1.25 mm diameter burr was firstly selected in 80.6% (25/31) patients,and 96.8%(30/31) patients used only 1 burr to complete the rotational atherectomy procedure. The complication rate was 9.8% (3/31) including 1 patient with coronary dissection and 3 patients with slow flow or no flow. There was 1 patent with both coronary dissection and slow flow. The procedure success rate was 96.8%(30/31). Interventional treatment related myocardial infarction occurred in 3 patients during hospitalization.The 30 patients with procedure success were followed up 36(11, 96) months. The incidence rate of major adverse cardiac and cerebral vascular events was 13.3% (4/30), of which the cardiogenic death rate was 3.3% (1/30), the myocardial infarction rate was 6.7% (2/30), cerebrovascular accident rate was 3.3%(1/30),and the target lesion revascularization rate was 6.7% (2/30). Conclusion Rotational atherectomy is safe and effective in the interventional treatment of coronary CTO lesions.