Cardiac lesions in fatal cases of recent myocardial ischaemia from a coronary care unit.

Abstract

In IOO consecutive deaths from a coronary care unit, the coronary arteries were examined microscopically in longitudinal sections (serial and semi-serial) so that the entire extramural part of each artery was scrutinized. Occluded coronary arteries were found in 88 cases, the occlusions being due to thrombi in 17, to the contents of soft atheromatous plaques in 22, and to a mixture of soft plaque content and thrombus in 49; thus in 7I cases the coronary occlusions are due basically to the rupture of soft plaques. After deep-freezing, the entire myocardium of each heart was examined naked eye in serial slices (using Nitro-B T) and selected areas microscopically. The findings allowed tentative groupings into single episode, double episode, and progressive lesions according to age structure. Correlation of the coronary and myocardial findings has been attempted.The establishment of a coronary care unit in the Royal Infirmary of Edinburgh provided an opportunity to make a detailed study of the hearts of fatal cases with especial reference to the condition of the coronary arteries in relation to the myocardial lesions. The policy of the unit is to admit '(i) any patient under 70 years of age who is suspected of having sustained a myocardial infarction within the preceding 48 hours ("routine admission"); and (2) any patient of any age who has a dangerous arrhythmia' (Lawrie et al., I967). gists, and hearts from all the coronary care unit cases were set aside for examination by one or other of the authors. After weighing the organ, the coronary arteries were dissected from the heart, the right, left anterior, and left circumflex vessels being traced from their orifices as far as possible on the external cardiac surface. The unopened arteries were fixed separately in neutral I0 per cent formal saline for I8 to 24 hours before trimming by removal of adherent fat. With a sharp scalpel, each vessel was cut into pieces about 2 cm. long, beginning peripherally and as far as possible placing the cuts so as to avoid an occlusion. Calcified segments were also left uncut until decalcified. Materials and methodsThe arterial segments were embedded in paraffin so that longitudinal sections would expose the whole length of the lumen. Complete serial sections at 5 [± were made from selected blocks where occlusion was seen or believed to have occurred; these amounted to half the cases. In other cases not cut serially, semi-serial sections were taken off at different levels until the whole lumen of the vessel was available for examination. Routine stains were employed and all the sections were scrutinized by the authors separately.After removal of the coronary arteries, the hearts were placed in a deep-freeze cabinet at -20°C. suspended from glass rods to preserve the shape of the heart. When convenient, the hearts were thawed to a suitable consistency at room temperature, and sliced on a Berkel automatic slicer. Transverse sections from apex to base of the ventricles were taken at approximately 5 mm. thickness, the valves and atria be...

Coronary thrombosis in pathogenesis of acute myocardial infarction. Histopathological study of coronary arteries in 108 necropsied cases using serial section.

“…By contrast, Bouch and Montgomery (1970) then reported that in 100 consecutive patients dying from myocardial ischaemia, occluded coronary arteries were found in 88 (88%), and stated that this contradiction of previous results was largely attributable to alterations of technique. In addition, they believed that case selection might have played a part.…”

Antithrombotic effect of a monoclonal antibody against tissue factor in a rabbit model of platelet-mediated arterial thrombosis.

“…9 " 12 The initiating event for the development of ischemia appears to be plaque rupture, the pathogenetic mechanism of which remains largely unexplained. 10 Plaque rupture initially causes platelet aggregation and subsequently leads to thrombus formation.…”

The natural history of platelet‐rich mural thrombi in systemic arteries of hyperchol‐esterolaemic monkeys: Light‐ and electron‐microscope observations

“…These observations emphasise the importance of distinguishing between " hard " and " soft '' atherosclerotic plaques (Montgomery, 1959;Bouch and Montgomery, 1970;Prathap, 1973b). Healing of mural thrombi in systemic arteries leads to relatively stable hard fibromuscular plaques.…”