[Cardiac magnetic resonance: clinical applications]. / Resonancia magnética cardíaca: aplicaciones clínicas.

Cardiovascular disease is the most frequent cause of mortality in the developed countries and represents a serious social, economic and health problem. Although very diverse, useful techniques exist for diagnosing cardiac diseases, it is frequently necessary to ask for more than one test to reach a specific diagnosis. Magnetic resonance is a harmless, well tolerated and safe technique, which is currently available in the majority of hospitals. This technique makes it possible in a single exploration to study the anatomy of the heart and to make a qualitative, semi-quantitative and quantitative assessment of the parameters of cardiac function. It provides information of cardiac and vascular anatomy and function in complex congenital cardiopathies. Besides, with the administration of intravenous contrast, it enables knowledge to be gained of myocardial viability in ischaemic cardiopathy. Hence, cardiac magnetic resonance is emerging as one of the most promising techniques for the study of congenital and acquired cardiac pathology.

Resonancia magnética cardíaca: aplicaciones clínicas / Cardiac magnetic resonance: clinical applications

La enfermedad cardiovascular es la causa más frecuentede mortalidad en los países desarrollados yconstituye un grave problema social, económico ysanitario. Aunque existen muy diversas técnicas útilespara diagnosticar las enfermedades cardíacas, con frecuenciaes preciso realizar más de una prueba para llegara un diagnóstico concreto. La resonancia magnéticaes una técnica inocua, bien tolerada y segura queactualmente se encuentra disponible en la mayoría delos centros hospitalarios. Esta técnica permite estudiaren una única exploración la anatomía del corazón yvalorar de forma cualitativa, semicuantitativa y cuantitativalos parámetros de función cardíaca. Es útil parael estudio de las enfermedades valvulares, miocardiopatíasy de la enfermedad pericárdica. Aporta informaciónde la anatomía y función cardíaca y vascular en lascardiopatías congénitas complejas. Además, con laadministración de contraste intravenoso, permiteconocer la viabilidad miocárdica en la cardiopatíaisquémica. Por tanto, la resonancia magnética cardíacase perfila como una de las técnicas más prometedoraspara el estudio de la patología cardíaca congénita yadquirida

Cardiovascular disease is the most frequent causeof mortality in the developed countries and representsa serious social, economic and health problem.Although very diverse, useful techniques exist fordiagnosing cardiac diseases, it is frequently necessaryto ask for more than one test to reach a specificdiagnosis. Magnetic resonance is a harmless, welltolerated and safe technique, which is currentlyavailable in the majority of hospitals. This techniquemakes it possible in a single exploration to study theanatomy of the heart and to make a qualitative, semiquantitativeand quantitative assessment of theparameters of cardiac function. It provides informationof cardiac and vascular anatomy and function incomplex congenital cardiopathies. Besides, with theadministration of intravenous contrast, it enablesknowledge to be gained of myocardial viability inischaemic cardiopathy. Hence, cardiac magneticresonance is emerging as one of the most promisingtechniques for the study of congenital and acquiredcardiac pathology

[Pericardial tamponade in rupture of a right coronary artery aneurysm]. / Perikardtamponade bei Ruptur eines Aneurysmas der RCA.

Cardiovascular magnetic resonance is a valid and accurate tool for the assessment of structural and functional disorders of the heart. Through combination of morphologic and functional studies, it is possible to form a quick diagnosis with a noninvasive examination. In this case, MR-imaging shows a pericardial effusion and a 5 x 5 cm large, well-circumscribed hematoma with displacement of the right coronary artery, which was also visible with other examination techniques as an unclear intracardial mass. At operation a large aneurysm of the right coronary artery was exposed, in addition to a hemorrhagic pericardial effusion.

[Symptomatic true aneurysm of a venous bypass with compression of the right atrium]. / Symptomatisches echtes Aneurysma eines Venenbypass mit Kompression des rechten Vorhofes.

A symptomatic true aneurysm of a saphenous vein graft to the right coronary artery in a female patient twelve years after bypass surgery is presented. Beating heart surgery included resection of the aneurysmatic saphenous vein graft, reconstruction of the right atrium and coronary artery bypass grafting to the right coronary artery. The symptoms of aneurysms of vein grafts, the diagnostic procedures and the surgical treatment are discussed.

Symptomatic aneurysm of a saphenous vein graft with compression of the right atrium.

A symptomatic aneurysm of a saphenous vein bypass to the right coronary artery in a 77-year-old female patient is presented. Surgical therapy included resection of the aneurysmal saphenous vein graft, reconstruction of the right atrium, and coronary artery bypass grafting (CABG) to the right coronary artery.

Ultrastructural Evaluation of Postischemic Cell Death (Lethal Reperfusion Injury) in Porcine Hearts.

This study investigated whether reperfusion results in an increase of ultrastructurally determined myocardial injury in pig hearts. The left anterior descending coronary artery (LAD) was distally occluded in 12 pigs for 35-45 minutes and then reperfused for 3 hours. At the end of ischemia, as well as after 3 hours of reperfusion, one transmural biopsy was removed from the center of the risk region and subdivided into four-specimens, representing the subendocardial (I), subendo-midmyocardial (II), subepi-midmyocardial (III), and subepicardial layers (IV). The degree of injury was assessed by electronmicroscopy and was scored as reversible (1), an almost equal mixture of reversible and irreversible (2), and totally irreversible (3) damage. In addition, infarct size was determined as the ratio of infarcted (tetrazolium stain) to ischemic (dye technique) myocardium. Infarct sizes ranged from 29.3% to 93% (mean 61.2%). The scores of injury of the four tissue layers before and after reperfusion did not differ significantly: layer I, 2.4 +/- 0.8/2.3 +/- 0.9; layer II, 2.2 +/- 0.9/2.0 +/- 0.9; layer III, 1.8 +/- 0.9/2.0 +/- 0.9; and layer IV, 1.6 +/- 0.9/1.3 +/- 0.6. The means of the four layers were almost identical at the end of ischemia (2.1 +/- 0.8) and after 3 hours of reperfusion (2.0 +/- 0.6). A linear regression analysis with 95% confidence limits of the score values before and after reperfusion indicated that maximally 25% of a mean final infarct size of about 50% may be due to lethal reperfusion injury. This study suggests that cell death in regional ischemia and reperfusion occurs predominantly during ischemia and not during reperfusion.

Ischemia affects cardiac proteins in healthy animals less severely than in human patients.

BACKGROUND: Recently, our group showed that in human hearts proteins are extremely sensitive to ischemic injury. The purpose of this investigation was to evaluate the effects of ischemia on contractile and cytoskeletal proteins in rabbit and pig hearts and to compare these findings with those obtained in humans. METHODS: Rabbit hearts were arrested by perfusion with Euro-Collins solution at different temperatures. Hearts perfused with buffer served as controls. Tissue samples were incubated for varying time intervals and processed for immunohistochemistry and electron microscopy. Porcine hearts were treated in the same manner. Changes in the localization of myosin, desmin, and tropomyosin antibodies were evaluated and the degree of ischemic injury was determined by electron microscopy. RESULTS: Healthy animal hearts tolerate ischemia better than human hearts. Cardiac proteins are more sensitive to ischemia than the ultrastructural cellular organelles. Temperatures as low as 0 degree C produce more cell damage than 4 degrees C and should therefore be avoided. The Euro-Collins solution protects the myocardium better than buffer. CONCLUSIONS: We conclude that healthy animal hearts are more resistant to ischemia than diseased human hearts and that results from experimental studies should be interpreted with caution with regard to the human situation.