Histochemische Studien über die Infarktausdehnung bei temporärer regionaler Myokardischämie beim Schwein*

Abstract

ZusammenfassungZiel der Untersuchungen war es, nach temporä-rer Ischämie eines umschriebenen Myokardbezirks das nach längerer Reperfusion resultierende Verhältnis von toten zu revitalisierten Herzmuskelzellen und dessen Einfluß auf das Kontraktionsverhalten des betrachteten Bezirks zu studieren.Bei 32 jungen Schweinen wurde eine Woche nach einer temporären Koronarokklusion das Versorgungsgebiet der betroffenen Arterie mit Lichtgrün markiert; dann wurden in Gefrier schnitten des gesamten Herzquerschnitts GOT und SDH angefärbt. Die enzymfreien i.e. nekrotischen Flächen wurden denen des Versorgungsgebietes gegenübergestellt. Bei 20 von diesen Schweinen waren die Bewegungen intramyokardialer Metallmarker in der Randzone des ischämischen Bezirks röntgenkinematographisch beobachtet worden. Wir fanden, daß das Verhältnis von Nekrose zu Versorgungsgebiet in direkter Relation zur Ischä-miedauer steht. Bei 15 bis 30 Minuten Ischämie traten erste zentrale Nekrosen auf; bei längerer Okklusion dehnten sich diese zentrifugal aus und nahmen bei 45 Minuten 26%, bei 60 Minuten 34%, bei 90 Minuten 51%, bei 180 Minuten 61% und bei permanenter Okklusion 81% des Versorgungsgebietes ein. Wenn der nekrotische Anteil 30% betrug, war die Kontraktionsfähigkeit des gesamten Versorgungsgebietes auf 30-40% der Werte vor Ischämie reduziert, mehr als 50% Nekroseanteil führten zur Adynamie des gesamten Bezirks. Histochemical Studies of the Extension of Necrosis Following Temporary Regional Myocardial Ischemia in PigsThe purpose of the investigations described was to determine the relation between necrotic and resuscitated myocardium after a prolonged period of reperfusion following temporary regional ischemia. The influence of this relation on the behaviour of contraction of the primarily ischemic area was studied.In 32 young pigs a temporary coronary artery occlusion of 15-180 minutes was performed. One week later the area supplied by the afflicted artery was stained with lightgreen. Afterwards the hearts were removed and cold microtome sections of the entire diameter were taken for GOT-und SDH-staining.The areas free of these enzymes were compared with those marked with lightgreen. In 20 of the pigs the movements of intramyocardial metal markers within the ischemic area had been studied before, during and up to one week after the occlusion cineradiographically.It was found that the extent of the necrotic area A N within the supplied area A y depended on the duration of ischemia. After 15 to 30 minutes of occlusion necrosis appeared in the centre, after 45 minutes 26%, after 60 minutes 34%, after 90 minutes 51%, after 180 minutes 61% and after permanent occlusion 81% of the area supplied by this artery were found to be dead. When 30% of the supplied area were necrotic, the amount of active movements of the supplied area was reduced to 30-40% of the preocclusion value. When the necrotic area was larger than 50%, the whole area was akinetic.

Critical Analysis of Intra-aortic Balloon Counterpulsation and Transapical Left Ventricular Bypass in the Sufficient and Insufficient Circulation

“…In the initial hours after induction of a myocardial infarction, dynamic processes occur in which normal, ischemic, and areas with morphological damage blend into one another (13,23,24). According to Hetzer and co-workers, the ferst signs of necrosis can be expected after 30 to 45 minutes of ischemia; the necrotic area then extends centrifugally (23,24).…”

“…In the initial hours after induction of a myocardial infarction, dynamic processes occur in which normal, ischemic, and areas with morphological damage blend into one another (13,23,24). According to Hetzer and co-workers, the ferst signs of necrosis can be expected after 30 to 45 minutes of ischemia; the necrotic area then extends centrifugally (23,24). As described by Cox and co-workers, the injured area, having its largest extent 18 hours after coronary occlusion, has a relatively constant size from 24 to 48 hours; correspondingly, healing mechanisms begin to work and the area affected by the process of infarction diminishes (13).…”

“…Unlike man and swine, dogs show transmural flow gradients, with the flow increasing towards the epicardium (60). (22,23,24). In both swine and man transmural infarction occurs, so that myocardial infarction in swine resembles that in man (19).…”