Objective To evaluate the utility of multi-slice computed tomography (MSCT) in assessing acute non-reperfused myocardial infarct size. Methods Seven domestic pigs (mean weight 17.3 ± 1.9 kg) underwent ligation of...Objective To evaluate the utility of multi-slice computed tomography (MSCT) in assessing acute non-reperfused myocardial infarct size. Methods Seven domestic pigs (mean weight 17.3 ± 1.9 kg) underwent ligation of the distal left anterior descending artery to establish a model of acute myocardial infarction (MI). MSCT and triphenyltetrazolium chloride (TTC) staining were performed two hours later. The following data were acquired and analyzed:MI volume (%), CT values of the infarcted region, left ventricular cavity and normal cardiac tissue at various scanning time-points (1, 5, 10, 15, 20 min after contrast injection). Results Using MSCT, the overall MI volume showed a time-dependent decrease, with a reduction of 28.87%after 20 min. The greatest reduction occurred at the 5 min time-point. In TTC staining, MI volume was 9.87%± 2.44%. When MI size, as determined by MSCT, was compared with that by TTC staining in Bland-Altman plots, there was a better agreement at 5, 10, and 15 min time-points at 1 and 20 min. Conclusions The study indicates that double-phase scanning examination using MSCT is a useful tool to assess MI size, and the optimal late-phase scanning time-point set within 5-15 min of contrast injection.展开更多
Objective To investigate the safety and efficacy of a self-developed novel multi-electrode radiofrequency ablation catheter （Spark） for catheter-based renal denervation （RDN）. Methods A total of 14 experimental mi...Objective To investigate the safety and efficacy of a self-developed novel multi-electrode radiofrequency ablation catheter （Spark） for catheter-based renal denervation （RDN）. Methods A total of 14 experimental miniature pigs were randomly divided into four groups （55°＆ 5-watt, 55°＆ 8-watt, 65°＆ 5-watt, and 65° ＆ 8-watt groups）. Spark was used for left and right renal artery radiofrequency ablation. Blood samples collected from renal arteries and veins as well as renal arteriography were performed on all animals before, immediately after, and three months after procedure to evaluate the effects of Spark on the levels of plasma renin, aldosterone, angiotensin I, and angiotensin II as well as the pathological changes of renal arteries. Results One pig died of an anesthetic accident, 13 pigs successfully underwent the bilateral renal artery ablation. Compared with basic measurements, pigs in all the four groups had significantly decreased mean arterial pres- sure after procedure. Histopathological analysis showed that this procedure could result in intimal hyperplasia, significant peripheral sympa- thetic nerve damage in the renal arteries such as inflammatory cell infiltration and fibrosis in perineurium, uneven distribution of nerve fibers, tissue necrosis, severe vacuolization, fTagmented and unclear nucleoli myelin degeneration, sparse axons, and interruption of continuity. In addition, the renal artery radiofrequency ablation could significantly reduce the levels of plasma renin, aldosterone, angiotensin I, and angio- tensin II in pigs. Conclusions The results suggest that this type of multi-electrode catheter-based radiofrequency ablation could effectively remove peripheral renal sympathetic nerves and reduce the activity of systemic renin-angiotensin system in pigs, thus facilitating the control of systemic blood pressure in pigs.展开更多
文摘Objective To evaluate the utility of multi-slice computed tomography (MSCT) in assessing acute non-reperfused myocardial infarct size. Methods Seven domestic pigs (mean weight 17.3 ± 1.9 kg) underwent ligation of the distal left anterior descending artery to establish a model of acute myocardial infarction (MI). MSCT and triphenyltetrazolium chloride (TTC) staining were performed two hours later. The following data were acquired and analyzed:MI volume (%), CT values of the infarcted region, left ventricular cavity and normal cardiac tissue at various scanning time-points (1, 5, 10, 15, 20 min after contrast injection). Results Using MSCT, the overall MI volume showed a time-dependent decrease, with a reduction of 28.87%after 20 min. The greatest reduction occurred at the 5 min time-point. In TTC staining, MI volume was 9.87%± 2.44%. When MI size, as determined by MSCT, was compared with that by TTC staining in Bland-Altman plots, there was a better agreement at 5, 10, and 15 min time-points at 1 and 20 min. Conclusions The study indicates that double-phase scanning examination using MSCT is a useful tool to assess MI size, and the optimal late-phase scanning time-point set within 5-15 min of contrast injection.
文摘Objective To investigate the safety and efficacy of a self-developed novel multi-electrode radiofrequency ablation catheter （Spark） for catheter-based renal denervation （RDN）. Methods A total of 14 experimental miniature pigs were randomly divided into four groups （55°＆ 5-watt, 55°＆ 8-watt, 65°＆ 5-watt, and 65° ＆ 8-watt groups）. Spark was used for left and right renal artery radiofrequency ablation. Blood samples collected from renal arteries and veins as well as renal arteriography were performed on all animals before, immediately after, and three months after procedure to evaluate the effects of Spark on the levels of plasma renin, aldosterone, angiotensin I, and angiotensin II as well as the pathological changes of renal arteries. Results One pig died of an anesthetic accident, 13 pigs successfully underwent the bilateral renal artery ablation. Compared with basic measurements, pigs in all the four groups had significantly decreased mean arterial pres- sure after procedure. Histopathological analysis showed that this procedure could result in intimal hyperplasia, significant peripheral sympa- thetic nerve damage in the renal arteries such as inflammatory cell infiltration and fibrosis in perineurium, uneven distribution of nerve fibers, tissue necrosis, severe vacuolization, fTagmented and unclear nucleoli myelin degeneration, sparse axons, and interruption of continuity. In addition, the renal artery radiofrequency ablation could significantly reduce the levels of plasma renin, aldosterone, angiotensin I, and angio- tensin II in pigs. Conclusions The results suggest that this type of multi-electrode catheter-based radiofrequency ablation could effectively remove peripheral renal sympathetic nerves and reduce the activity of systemic renin-angiotensin system in pigs, thus facilitating the control of systemic blood pressure in pigs.
