Usefulness of pirenzepine, an M1 antimuscarinic agent, for effort myocardial ischemia.
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)
Marraccini
P
P
CNR Institute of Clinical Physiology, University of Pisa, Italy.
Orsini
E
E
Nassi
G
G
Michelassi
C
C
L'Abbate
A
A
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*
D010890:Pirenzepine; D007548:Isosorbide Dinitrate