Table 1 Adverse effects of the vasodilator stressor agents (data derived from 2016 ASNC imaging guidelines for SPECT nuclear cardiology procedures [1], from Subbiah et al. [19], and from Doukky et al. [20])
| Â | Dipyridamole | Adenosine | Regadenoson |
|---|---|---|---|
Minor side effects (total) | ~ 50% | ~ 80% | ~ 50% |
 flushing | 3% | 35–40% | 17% |
 nonspecific chest pain | 20% | 25–30% | 11% |
 dyspnea | 10% | 20% | 25% |
 dizziness | 12% | 7% | 7% |
 hypotension | 5% | 5% | 5% |
 nausea | 5% | 5% | 6% |
 headache | 12% | 10% | 29% |
 abdominal discomfort | 5–10% | 5–14% | 6–17% |
 Transient conduction abnormalities: | |||
  Overall | 2% | 8.5% | 4% |
  Transient 2nd degree AVB | 1–2% | 4% | 0.1% |
 Transient ST depression of ≥1 mm | 8% | 5–7% | 1–2% [20] |
Major side effects | < 1% | < 1% | < 1% |
 Complete AVB | < 1% | < 1% | Rare |
 Severe (> 2 mm) ST depression | < 1% | < 1% | < 1% |
 Fatal or nonfatal MI | Extremely rare | Extremely rare | Extremely rare |
 Stroke | Extremely rare | Extremely rare | Extremely rare |
 Seizures | Rare | Rare | Rare |
Comments | Symptoms may last longer (15–25 min) than with other vasodilator stressors; Aminophylline frequently required | Due to a short half-time, most side effects resolve in a few (< 10) seconds after discontinuation of the infusion; Aminophylline rarely required | Most adverse reactions begin soon after injection and resolve within 15 min (headaches may last up to 30 min) |