Significance of exercise-induced ST segment elevation in Q leads in patients with a recent myocardial infarction and an open infarct-related artery

Cardioprotective effects of the combined use of puerarin and Danshensu on acute ischemic myocardial injury in rats

Ischemic heart diseases are the leading cause of death in both developed and developing countries over the past decades. The aim of this study was to investigate the cardioprotective effects of the complex preparation (called Shenge), made of puerarin and Danshensu, on acute ischemic myocardial injury in rats and its underlying mechanisms. The left anterior descending (LAD) coronary artery was occluded to induce myocardial ischemia in hearts of SD rats. Shenge was injected into the tail vein 15 min after occlusion at doses of 0, 30, 60 or 120 mg/kg. Then, the ST elevation was measured at 60, 120 and 240 min after Shenge administration. The infarct size, serum levels of creatine kinase isoenzyme-MB (CK-MB), lactate dehydrogenase (LDH), superoxide dismutase (SOD) and malondialdehyde (MDA), and the ST elevation were measured after the rats were killed. Shenge decreased the ST elevation induced by acute myocardial ischemia, reduced infarct size, serum levels of CK-MB, LDH and MDA and increased the serum activity of SOD in a dose-dependent manner. The combined use of puerarin and Danshensu at a ratio of 1:1 shows the most effective activity. In conclusion, Shenge exerts significant cardioprotective effects against acute ischemic myocardial injury in rats, likely through its antioxidant and antilipid peroxidation properties, and thus may be used as an effective and promising medicine for both prophylaxis and treatment of ischemic heart disease.

Microvascular perfusion 1 week and 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging

OBJECTIVE

To characterise the evolution of myocardial perfusion during the first 6 months after myocardial infarction by first-pass perfusion cardiovascular magnetic resonance imaging (CMR) and determine its significance.

DESIGN

Prospective cohort design.

SETTING

Single-centre study in a teaching hospital in Spain.

PATIENTS

40 patients with a first ST-elevation myocardial infarction, single-vessel disease and thrombolysis in myocardial infarction (TIMI) grade 3 flow (stent in 33 patients) underwent rest and low-dose dobutamine CMR 7 (SD 1) and 184 (SD 11) days after infarction. Microvascular perfusion was assessed at rest by visual assessment and quantitative analysis of first-pass perfusion CMR. Of the 640 segments, 290 segments subtended by the infarct-related artery (IRA) were focused on.

RESULTS

Both 1 week and 6 months after infarction, segments with normal perfusion showed more wall thickening, contractile reserve and wall thickness, and less transmural necrosis, p <0.05 in all cases. Of 76 hypoperfused segments at the first week, 47 (62%) normalised perfusion at the sixth month. However, 42 segments (14% of the whole group) showed chronic abnormal perfusion; these segments showed worse CMR indices in the late phase (p<0.05 in all cases).

CONCLUSIONS

In patients with an open IRA, more than half of the segments with abnormal perfusion at the first week are normally perfused after six months. First-pass perfusion CMR shows that in a small percentage of segments, abnormal perfusion may become a chronic phenomenon-these areas have a more severe deterioration of systolic function, wall thickness, contractile reserve and the transmural extent of necrosis.