Objective To investigate the effects on myocardial perfusion of simultaneous antegrade/retrograde cardiopiegia （SARC） through a single coronary artery and coronary sinus （CS）. Methods SARC was conducted in isolated pig hearts through CS in conjunction with the left anterior descending （LAD）, the left circumflex （LCX）, or the right coronary artery （RCA） respectively. After injecting magnetic resonance （MR） contrast agent （gadolinium diethyienetriamine pentaacetic acid, Gd-DTPA） into arterial or venous route, the distribution of Gd-DTPA with magnetic resonance imaging（MRI） was monitored and the effluent from the venting coronary arteries to assess the efficacy of SARC for myocardial perfusion was measured. Results Injection of Gd-DTPA into a perfusing artery during SARC resulted in increased signal intensity not only in the territory of the perfusing artery but also in the areas normally served by the other two venting coronary arteries （including the right ventrieuiar free wall）. With Gd DTPA given into the CS during SARC, the myocardium in the territories of the two venting coronary arteries was lightened. Signal intensity of the myocardium in the perfusing artery territory and right ventricuiar free wall remained unchanged. Moreover, a significant amount of effluent was collected from the venting coronary arteries during SARC： the LAD 10.5-17.7 ml/min; LCX 9.7-15.2 ml/min, and RCA 4.7-7.8 ml/min. Conclusion SARC through a single coronary artery and CS can provide homogeneous perfusion to the entire heart and is sufficient to prevent ischemic injury in the myocardium normally supported by the venting coronary arteries.
ObjectiveTo estimate the radiation dose (RD) to the general public and nuclear medicine technicians from patients undergoing 99mTc-methoxy isobutyl isonitrile (MIBI) myocardial perfusion imaging. MethodsFrom January to June 2015, 55 patients including 30 males and 25 females aged between 25 and 87 years[averaging (63.6±15.1)years] ready to undergo myocardial perfusion scintigraphy with 99mTc-MIBI were prospectively recruited in this study. Approximately at hour 1.5 after injection of 99mTc-MIBI, whole-body dose-equivalent rate was measured with a radiation-survey meter at 0.3 meter and 1.0 meter from the patients. On the basis of human 99mTc-MIBI metabolic rate proposed by the International Commission of Radiological Protection and human social contact model proposed by the National Council on Radiation Protection and Measurements, the RDs to the general public from patients who had completed 99mTc-MIBI myocardial perfusion imaging and left nuclear medicine department were calculated. On the assumption that a nuclear medicine technician typically spent 5 minutes at a distance of 0.3 meter for positioning the patient, the technician's RD was also estimated. ResultsThe RD to a family member sleeping with the patient at night was predicted to be 42.88-160.55 μSv, to a family member contacting the patient at daytime 7.50-29.38 μSv, to a colleague 9.89-38.78 μSv and to a nearby passenger 124.48-466.06 μSv. The RD to a technician per 99mTc-MIBI myocardial perfusion imaging procedure was predicted to be 1.72-6.44 μSv. ConclusionThe predicted RDs to the general public and technicians from exposure of patients undergoing 99mTc-MIBI myocardial perfusion imaging are significantly lower than the regulatory dose limits.
ObjectiveTo evaluate the value of myocardial perfusion change before and after coronary artery bypass grafting (CABG) in predicting postoperative major adverse cardiovascular events (MACE).MethodsA total of 70 CABG patients who received CABG completed by the same operator from January to November 2017 were selected, including 45 males and 25 females with an average age of 64.83±9.09 years. The patients were divided into two groups according to whether the patients had MACE after 1 year of the surgery, including a non-MACE group (group A, n=60) and a MACE group (group B, n=10). The clinical data of patients were compared.ResultsThere were statistical difference in the myocardial contrast echocardiography (MCE) score in the group A before and after surgery (P<0.05), and there were statistically significant differences in the left ventricular size and left ventricular ejection fraction (LVEF) value before and 1 year after surgery (P<0.001), but no statistically significant difference in the size of left atrium (P=0.075). There was no significant difference in the preoperative and postoperative MCE score, and preoperative and postoperative 1-year cardiac ultrasound score in the group B (P>0.05).ConclusionThe change of myocardial perfusion after CABG surgery is associated with postoperative MACE. The evaluation of myocardial perfusion before and after CABG surgery is of great significance for the prognosis evaluation of patients.