Tachycardia: dipyridamole potentiated the cardiac effects of adenosine.

Clinical bottom line (level 1b)

  1. In healthy subjects, dipyridamole before adenosine increased heart rate by about 20 beats per minute.
Conradson et al: Acta Physiologica Scandinavia 1987; 129: 387-391
Expires May 2004

The study

Single-blinded ?concealed randomised cross-over trial with intention-to-treat
Setting: general hospital, UK

8 patients (aged range 23 to 40 years, 62% male) healthy subjects, except one with asthma
Control Group: (n = 8, 8 analysed): saline
Experimental Group: (n = 8, 8 analysed): dipyridamole 0.4 mg/ kg iv over 10 min
After a 20 min rest, adenosine was infused. On days when saline was given, all subjects started with 0.02 mg/kg/min. On days when dipyridamole was given, 4 subjects started with 0.005 and four with 0.02 mg/kg/min. The infusion was increased stepwise up to a maximum of 0.1 mg/kg/min with each infusion rate maintained for 6 mins.
100% followed for 30 minutes

The evidence

dipyridamole and adenosine (0.03 mg/kg/min) vs saline and adenosine (0.07 mg/kg/min)
Outcome Control Group
(SD)		 Experimental Group
(SD)		 Mean Difference
(95% CI)
increase of heart rate 12
(10) 		29
(13) 		17
(4.2 to 30)

  • Skin temperature increased after adenosine.
  • There was no clear change in blood pressure.

    • Comments

    1. This is a very small study, but the results should still be noted.

    Citation

    1. Conradson T-B, Dixon CM, Clarke B, et al: Cardiovascular effects of infused adenosine in man: potentiation by dipyridamole. Acta Physiologica Scandinavia 1987; 129: 387-391
    Contributor: Clare Wotton, May 2001
    Reviewer: Emma Boulton

    Clinical Question.
    Patient healthy subjects
    Intervention or Exposure dipyridamole after adenosine
    Comparison dipyridamole
    Outcome heart rate