title: Usefulness of pirenzepine, an M1 antimuscarinic agent, for effort myocardial ischemia.
abstract: This study evaluated the effect of pirenzepine, an M1 antimuscarinic agent, on exercise duration and ischemic threshold in patients with angiographically documented coronary artery disease and clear-cut ST depression (greater than 0.2 mV, 0.08 second after the J point) during ergometric stress testing. Twenty-five patients, mean age 56 +/- 8 years, underwent 3 randomized multistage bicycle exercise stress tests after intravenous administration of saline solution (2 ml), isosorbide dinitrate (1 mg) and pirenzepine (2 mg). Isosorbide dinitrate, an endothelium-independent coronary dilating agent, was used as a reference drug. Compared with saline, both pirenzepine and isosorbide dinitrate significantly improved time to ischemia (0.15 mV ST-segment depression) from 6.5 +/- 2 to 7.8 +/- 2 and 8.6 +/- 2 minutes and rate-pressure product at ischemia from 21,498 +/- 4,903 to 24,083 +/- 6,692 and 24,547 +/- 5,390 mm Hg.beats/min, respectively. Compared with saline, pirenzepine did not induce significant changes in blood pressure either at rest or during exercise, whereas it decreased resting heart rate from 71 +/- 9 to 60 +/- 11 beats/min (p less than 0.01) and induced a significant increment of heart rate during ischemia from 117 +/- 18 to 126 +/- 21 beats/min (p less than 0.05). Compared with saline, isosorbide dinitrate reduced systolic blood pressure at rest from 132 +/- 12 to 112 +/- 12 mm Hg, increased heart rate at rest from 71 +/- 10 to 84 +/- 16 beats/min and heart rate at ischemia from 117 +/- 18 to 132 +/- 16 beats/min.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: CNR Institute of Clinical Physiology, University of Pisa, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Marraccini
authors.forename: E
authors.initials: E
authors.lastname: Orsini
authors.forename: G
authors.initials: G
authors.lastname: Nassi
authors.forename: C
authors.initials: C
authors.lastname: Michelassi
authors.forename: A
authors.initials: A
authors.lastname: L'Abbate
mesh_terms: D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D001794:Blood Pressure / Q000187:drug effects; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007548:Isosorbide Dinitrate / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D010890:Pirenzepine / Q000627:therapeutic use*
chemical_list: D010890:Pirenzepine; D007548:Isosorbide Dinitrate