Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs.
Five anaesthetized open chested dogs were studied by measuring left anterior descending (LAD) coronary blood flow, at rest, after atrial pacing and after Isoprenaline infusion. The LAD was then stenosed in order to reduce the hyperaemic response and then the study was repeated. During the control s...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Ordem dos Médicos
1979-04-01
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| Series: | Acta Médica Portuguesa |
| Online Access: | https://www.actamedicaportuguesa.com/revista/index.php/amp/article/view/4334 |
| _version_ | 1811344815094235136 |
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| author | R Seabra-Gomes A F Rickards D J Parker |
| author_facet | R Seabra-Gomes A F Rickards D J Parker |
| author_sort | R Seabra-Gomes |
| collection | DOAJ |
| description |
Five anaesthetized open chested dogs were studied by measuring left anterior descending (LAD) coronary blood flow, at rest, after atrial pacing and after Isoprenaline infusion. The LAD was then stenosed in order to reduce the hyperaemic response and then the study was repeated. During the control situation LAD flow was shown to increase with the increase in heart rate. Although the partial occlusion did not drop resting coronary flow, it actually fell under stress conditions to 68 % of the control values. The importance of this observation is that although one might expect flow in a stenosed vessel to increase to a maximum limited by the stenosis, this in fact does not happen. lt appears that with increasing stress, local ischaemia produces a rise in coronary resistance. Such a mechanism may explain the occurrence of myocardial infarction without proximal occlusion of coronary vessels and may explain the discrepancy between the time course of myocardial infarction as observed following experimental coronary ligation and that seen in man.
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| first_indexed | 2024-04-13T19:53:46Z |
| format | Article |
| id | doaj.art-5dda96569e4349eebd32ff2ae0ad2c2d |
| institution | Directory Open Access Journal |
| issn | 0870-399X 1646-0758 |
| language | English |
| last_indexed | 2024-04-13T19:53:46Z |
| publishDate | 1979-04-01 |
| publisher | Ordem dos Médicos |
| record_format | Article |
| series | Acta Médica Portuguesa |
| spelling | doaj.art-5dda96569e4349eebd32ff2ae0ad2c2d2022-12-22T02:32:25ZengOrdem dos MédicosActa Médica Portuguesa0870-399X1646-07581979-04-011210.20344/amp.4334Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs.R Seabra-GomesA F RickardsD J Parker Five anaesthetized open chested dogs were studied by measuring left anterior descending (LAD) coronary blood flow, at rest, after atrial pacing and after Isoprenaline infusion. The LAD was then stenosed in order to reduce the hyperaemic response and then the study was repeated. During the control situation LAD flow was shown to increase with the increase in heart rate. Although the partial occlusion did not drop resting coronary flow, it actually fell under stress conditions to 68 % of the control values. The importance of this observation is that although one might expect flow in a stenosed vessel to increase to a maximum limited by the stenosis, this in fact does not happen. lt appears that with increasing stress, local ischaemia produces a rise in coronary resistance. Such a mechanism may explain the occurrence of myocardial infarction without proximal occlusion of coronary vessels and may explain the discrepancy between the time course of myocardial infarction as observed following experimental coronary ligation and that seen in man. https://www.actamedicaportuguesa.com/revista/index.php/amp/article/view/4334 |
| spellingShingle | R Seabra-Gomes A F Rickards D J Parker Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs. Acta Médica Portuguesa |
| title | Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs. |
| title_full | Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs. |
| title_fullStr | Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs. |
| title_full_unstemmed | Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs. |
| title_short | Effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs. |
| title_sort | effects of acute ischaemia induced by atrial pacing on coronary blood flow in dogs |
| url | https://www.actamedicaportuguesa.com/revista/index.php/amp/article/view/4334 |
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