Effects of bamiphylline on exercise testing in patients with syndrome X.

Abstract

An abnormal stimulation of adenosine A1-receptors has been suggested to play a role in the pathogenesis of both chest pain and ischemia-like electrocardiographic changes in patients with syndrome X and a nonselective adenosine antagonist (theophylline) has been reported to be beneficial in these patients. In this study we investigated the acute effects of bamiphylline, a specific A1-receptor antagonist, in 16 patients with syndrome X (14 women, age 57 +/- 6 years), with both angina and ST-segment depression inducible during exercise testing. All patients underwent two treadmill exercise tests (Bruce modified protocol) on 2 separate days, 5 minutes after the end of randomized intravenous infusion of either placebo (saline solution) or bamiphylline (300 mg). Severity of chest pain was assessed by a 100 mm visual analogic scale. There were no significant differences in resting heart rate and blood pressure after bamiphylline or placebo. Rate-pressure product (20 600 +/- 5000 vs 20 200 +/- 5200 bpm.mmHg), time to 1 mm ST depression (549 +/- 196 vs 581 +/- 201 sec), time to angina (519 +/- 209 vs 571 +/- 196 sec), and exercise duration (717 +/- 134 vs 676 +/- 166 sec) were also not significantly different after bamiphylline or placebo, but there was a mild reduction of the severity of exercise-induced chest pain (30 +/- 22 vs 39 +/- 20 mm, p < 0.05) with the active drug. Thus, in patients with syndrome X, bamiphylline does not improve exercise-induced ST changes, suggesting that A1-receptors are not significantly involved in their appearance. In addition, bamiphylline had little effect on anginal pain, suggesting that this cannot be mediated exclusively by A1-receptor stimulation in these patients.

• Authors: G A Lanza, A Gaspardone, V Pasceri, M Perino, G Colonna, F Tomai, F Crea, P A Gioffrè, A Maseri
• Journal: Giornale italiano di cardiologia (G Ital Cardiol) Vol. 27 Issue 1 Pg. 50-4 (Jan 1997) ISSN: 0046-5968 [Print] Italy
• PMID: 9199943 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Purinergic P1 Receptor Antagonists
• Vasodilator Agents
• Theophylline
• bamifylline

Topics

• Angina Pectoris (drug therapy, etiology, physiopathology)
• Blood Pressure (drug effects, physiology)
• Electrocardiography (drug effects)
• Exercise Test
• Female
• Heart Rate (drug effects, physiology)
• Humans
• Infusions, Intravenous
• Microvascular Angina (complications, diagnosis, physiopathology)
• Middle Aged
• Pain Measurement
• Purinergic P1 Receptor Antagonists
• Theophylline (administration & dosage, analogs & derivatives, therapeutic use)
• Vasodilator Agents (administration & dosage, therapeutic use)