Haemodynamic effects of a new beta 1-receptor agonist in acute myocardial infarction. A useful antidote to unwanted cardiac effects of beta-blocking agents.
The haemodynamic effects of a new beta 1-receptor agonist, 1-(4 hydroxyphenoxy) 3-isopropylamino-2-propanol, were studied in 25 patients after acute myocardial infarction using non-invasive methods. The drug caused an increase in systolic blood pressure and pulse pressure, without change in diastolic blood pressure, and a slight increase in heart rate and reduction in the pre-ejection period. These changes were greater in patients without a history of left heart failure. It is suggested that this cardioselective drug possesses positive inotropic activity but only slight positive chronotropic activity. The substance has been further investigated as a possible antidote to unwanted cardiac side effects of the cardioselective beta-blocker, metoprolol. The changes in the cardiovascular dynamics caused by metoprolol in patients with acute myocardial infarction were promptly reversed by this new beta 1-agonist. With its positive inotropic properties and its efficacy in reversing the effects of a cardioselective beta-blocker, the drug is a potentially useful pharmacological agent to support an acutely depressed myocardium in patients on beta-blocking agents.
D000208:Acute Disease; D000318:Adrenergic beta-Agonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D006321:Heart / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008790:Metoprolol / Q000009:adverse effects*; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D009203:Myocardial Infarction / Q000188:drug therapy / Q000503:physiopathology*; D011412:Propanolamines / Q000009:adverse effects* / Q000494:pharmacology* / Q000627:therapeutic use; D013268:Stimulation, Chemical
D000318:Adrenergic beta-Agonists; D011412:Propanolamines; D008790:Metoprolol