| Propranolol in experimental myocardial ischemia: dissociation of effects on contraction and epicardial ST segments. | |
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MedLine Citation:
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PMID: 961587 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Recent studies have suggested that propranolol decreases the extent of myocardial injury in acute ischemia. Although other studies have shown that global myocardial performance is depressed, zonal effects of propranolol in this setting are unknown. Therefore, the effect of propranolol (1.0 mg. per kilogram) was investigated in nine dogs with the use of Walton-Brodie strain gauge arches and local epicardial electrograms (10 to 12 sites). The heart rate effects of propranolol were controlled by atrial pacing. After coronary occlusion, heart rate increased slightly without a significant change in blood pressure. Following the infusion of propranolol, heart rate decreased significantly from 165.0 +/- 3.5 to 126.2 +/- 4.7 beats per minute (p less than 0.001) while both the systolic and diastolic blood pressures showed insignificant changes. After coronary occlusion, nonischemic zone tension showed no significant changes; however, propranolol decreased total tension from 105.2 +/- 2.5 per cent to 66.8 +/- 4.7 (p less than 0.001). Similarly, propranolol further decreased total tension in the border zone from 84.4 +/- 6.7 per cent (p less than .02) to 50.6 +/- 5.1 (p less than 0.01). Ischemic zone tension also fell further (p less than 0.025) after propranolol. Restoration of prepropranolol heart rate had no significant effect on tension development. Following coronary occlusion, sigmaST increased from 5.7 +/- 2.2 to 72.9 +/- 20.1 mv. (p less than 0.001). Coincident with the decrease in heart rate and tension development induced by propranolol, sigmaST decreased to 60.8 +/- 18.8 mv. (p less than 0.05). When the heart rate was restored to prepropranolol level, sigmaST again rose to 73.2 +/- 16.9 mv. (p less than .005). Thus, propranolol does effect an improvement in ischemic injury which is related, at least in part, to the induced decrease in heart rate. A concomitant substantial decrease in local tension development also occurs, however. The latter observations may limit the potential usefulness of propranolol in this setting. |
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Authors:
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M M Bodenheimer; V S Banka; R H Helfant |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: American heart journal Volume: 92 ISSN: 0002-8703 ISO Abbreviation: Am. Heart J. Publication Date: 1976 Oct |
Date Detail:
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Created Date: 1976-11-01 Completed Date: 1976-11-01 Revised Date: 2006-02-27 |
Medline Journal Info:
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Nlm Unique ID: 0370465 Medline TA: Am Heart J Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 481-6 Citation Subset: AIM; IM |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blood Pressure / drug effects Depression, Chemical Disease Models, Animal* Dogs Electrocardiography* Heart Rate / drug effects Myocardial Contraction / drug effects* Myocardial Infarction / drug therapy* Pacemaker, Artificial Propranolol / pharmacology*, therapeutic use |
| Chemical | |
Reg. No./Substance:
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525-66-6/Propranolol |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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