ST-segment dynamics during reperfusion period and the size of myocardial injury in experimental myocardial infarction.
نویسندگان
چکیده
BACKGROUND Exacerbation of ST elevation associated with reperfusion has been reported in patients with myocardial infarction. However, the cause of the "reperfusion peak" and relation of its magnitude to the size of myocardial damage has not been explored. The aim of our study was to assess the correlation between the ST-dynamics during reperfusion, the myocardium at risk (MaR), and the infarct size (IS). METHODS Infarction was induced in 15 pigs by a 40-minute-long balloon inflation in the left anterior descending coronary artery. Tetrofosmin Tc 99m was given intravenously after 20 minutes of occlusion, and ex vivo single photon emission computed tomography was performed to assess MaR. Maximal ST elevation in a single lead and maximal sum of ST deviations in 12 leads were measured before, during, and after occlusion from continuous 12-lead electrocardiographic monitoring. A gadolinium-based contrast agent was given intravenously 30 minutes before explantation of the heart. Final IS was estimated using ex vivo cardiac magnetic resonance imaging. RESULTS All pigs developed an anteroseptal infarct with MaR = 42% ± 9% and IS = 26% ± 7% of left ventricle. In all pigs, reperfusion was accompanied by transitory exacerbation of ST elevation that measured 1300 ± 500 μV as maximum in a single lead compared with 570 ± 220 μV at the end of occlusion (P < .001). The transitory exacerbation of ST elevation exceeded the maximal ST elevation during occlusion (920 ± 420 μV, P < .05). The ST elevation resolved by the end of the reperfusion period (90 ± 30 μV, P < .001). Exacerbation of ST elevation after reperfusion correlated with the final IS (r = 0.64, P = .025 for maximal ST elevation in a single lead and r = 0.80, P = .002 for sum of ST deviations) but not with MaR (r = 0.43, P = .17 for maximal ST elevation in a single lead and r = 0.49, P = .11 for sum of ST deviations). The maximal ST elevation in a single lead and the sum of ST deviations during occlusion did not correlate with either MaR or final IS. CONCLUSION In the experiment, exacerbation of ST elevation is common during restoration of blood flow in the occluded coronary artery. The magnitude of the exacerbation of ST elevation after reperfusion in experimentally induced myocardial infarction in pigs is associated with infarct size but not with MaR.
منابع مشابه
Study of the Duration, Outcomes, and Related Factors of Reperfusion Therapy in Patients with ST-Segment Elevation Myocardial Infarction
Background and Objective: One of the most important advancements regarding the care of patients with acute myocardial infarction is the administration of anti-coagulation medicines (e.g., streptokinase). However, it must be noticed that this medicine requires rapid and timely administration. Moreover, Percutaneous Coronary Intervention (PCI) is increasingly used as a method of revascularization...
متن کاملEffects of Postconditioning, Preconditioning and Perfusion of L-carnitine During Whole Period of Ischemia/ Reperfusion on Cardiac Hemodynamic Functions and Myocardial Infarction Size in Isolated Rat Heart
متن کامل
Prehospital and interhospital delay in the treatment of patients with acute myocardial infarction with ST segment elevation and strategies to improve it from the perspective of the process owners: The importance of time
Introduction: Fibrinolytic drugs are one of the important strategies for the treatment of patients with acute myocardial infarction with ST segment elevation, especially in small centers. This study was conducted with the aim of evaluating the distance with the global standard for fibrinolytic treatment and the viewpoints of experts in this regard. Materials and Methods: This cross-sectional st...
متن کاملEnzymatic and Immunogenic Changes of Myocardial Infarction
Diagnosis of myocardial infarction is very important in a patient with chest pain. Chest pain is not always present or it may be from other causes rather than myocardial infarction. Q wave is present in 30] of infarction. ST,T wave changes are present in all myocardial infarctions, but these changes also are present in myocardial ischernia. For these reasons diagnosis of myocardial infarction...
متن کاملThe effect of oxygen inhalation on cardiac biomarkers in patients presenting with acute ST-segment elevation myocardial infraction: A randomized clinical trial
Background: It is assumed giving oxygen to patients with acute myocardial infraction may increase the oxygenation of the ischemic tissue; however, the usefulness of oxygen in these patients has become a challenging topic. Thus, the present study aimed to determine the effect of oxygen inhalation on cardiac biomarkers in patients with acute myocardial infarction. Methods: This randomized cli...
متن کاملمعیارهای جدید برای تشخیص سریع سکته حاد قلبی در حضور بلوک شاخه ای چپ
It is a common Knowledge that the ECG diagnosis of myocardial infarction in the presence of left bundle branch block (LBBB) is extremely difficult and often impossible. Physicians frequenlly recommend that patients with chest pain in the presence of LBBB receive thrombolytic therapy or urgent coronary arteriography assuming that acute injury and ischemia cannot be interpreted in the presence o...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Journal of electrocardiology
دوره 44 1 شماره
صفحات -
تاریخ انتشار 2011