Long-term effects of xamoterol on left ventricular diastolic function and late remodeling: a study in patients with anterior myocardial infarction and single-vessel disease.
The purpose of the study was to examine whether the prolonged administration of the beta 1-adrenoceptor partial agonist xamoterol could improve left ventricular diastolic function and affect the global remodeling process of the left ventricle after anterior myocardial infarction. In 22 patients with anterior myocardial infarction and single-vessel disease, left ventricular angiography (+ Millar) was performed under basal conditions 1 to 2 months after the acute myocardial infarction. Eight patients were then treated for 3 months with placebo and 14 were treated with xamoterol (200 mg bid) and a second left ventricular angiographic study was performed. Angiograms were digitized frame by frame to derive the diastolic pressure-volume relationship and to compute wall stress. An index of elastic myocardial stiffness was computed at a constant stress of 30 kdynes/cm2 before and after treatment. To evaluate changes in left ventricular shape, segmental areas in anterior and inferior segments were computed and compared at end-diastole and end-systole. After xamoterol, left ventricular end-diastolic pressure and mean diastolic wall stress decreased (from 24 +/- 5 to 15 +/- 5 mm Hg and from 57 +/- 32 to 38 +/- 22 kdynes/cm2, respectively; both p less than .01 vs baseline and vs placebo). These changes were accompanied by a downward shift in the diastolic pressure-volume relationship and by a decrease in the index of myocardial stiffness from 526 +/- 270 to 371 +/- 194 kdynes/cm2 (p less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)
D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D006328:Cardiac Catheterization; D006332:Cardiomegaly / Q000188:drug therapy* / Q000503:physiopathology; D002986:Clinical Trials as Topic; D003327:Coronary Disease / Q000188:drug therapy* / Q000503:physiopathology; D003971:Diastole / Q000187:drug effects*; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000503:physiopathology; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D011412:Propanolamines / Q000627:therapeutic use*; D011859:Radiography; D013997:Time Factors; D017307:Xamoterol
D000318:Adrenergic beta-Agonists; D011412:Propanolamines; D017307:Xamoterol