Effects of Propranolol on Regional Myocardial Function, Electrograms, and Blood Flow in Conscious Dogs with Myocardial Ischemia
Open Access
- 1 August 1977
- journal article
- research article
- Published by American Society for Clinical Investigation in JCI Insight
- Vol. 60 (2), 353-360
- https://doi.org/10.1172/jci108783
Abstract
The effects of coronary occlusion and of subsequent propranolol administration were examined in 18 conscious dogs. Overall left ventricular (LV) function was assessed by measurements of LV pressure and dP/dt, and regional myocardial function was assessed by measurements of segment length (SL), velocity of SL shortening and regional myocardial “work”, i.e., pressure-length loops in normal, moderately, and severely ischemic zones. Regional intra-myocardial electrograms were measured from the same sites along with regional myocardial blood flow as determined by the radioactive microsphere technique. Coronary occlusion resulted in graded loss of function from the normal to severely ischemic zones with graded flow reduction and graded elevation of the ST segment. Propranolol depressed overall LV function, function in the normal zone (work fell by 17±4%), and in the majority of moderately ischemic segments (work fell by 7±3%). In severely ischemic segments the extent of paradoxical motion and post-systolic shortening was reduced by propranolol. After propranolol regional myocardial blood flow fell in the normal zone (11±2%) and rose in the moderately (15±4%) and severely (63±10%) ischemic zones. Thus, in the conscious dog with regional myocardial ischemia, propranolol induces a redistribution of myocardial blood flow, with flow falling in normal zones and rising in moderately and severely ischemic zones. The improvement in perfusion of ischemic tissue was associated with slight but significant depression of shortening, velocity, and work in the moderately ischemic zones and of paradoxical bulging and post-systolic shortening in the severely ischemic zone.This publication has 22 references indexed in Scilit:
- Propranolol in experimental myocardial ischemia: Dissociation of effects on contraction and epicardial ST segmentsAmerican Heart Journal, 1976
- Effects of isoproterenol on regional myocardial function, electrogram, and blood flow in conscious dogs with myocardial ischemia.JCI Insight, 1976
- Effects of allopurinol, propranolol and methylprednisolone on infarct size in experimental myocardial infarctionThe American Journal of Cardiology, 1976
- Regional Myocardial function in the conscious dog during acute coronary occlusion and responses to morphine, propranolol, nitroglycerin, and lidocaine.Circulation, 1976
- Distribution of coronary collateral flow in acute myocardial ischaemic injury: effect of propranololCardiovascular Research, 1976
- Effect of practolol on left ventricular dimensions during coronary occlusionThe American Journal of Cardiology, 1975
- Effect of propranolol and isoprenaline on regional left ventricular blood flow in experimental myocardial ischaemiaCardiovascular Research, 1975
- Propranolol in the Treatment of Acute Myocardial InfarctionCirculation, 1974
- Effects of various agents on regional ischemic myocardial injury: Electrocardiographic analysisAmerican Heart Journal, 1974
- Factors Influencing Infarct Size Following Experimental Coronary Artery OcclusionsCirculation, 1971