Abnormal thallium 201 scintigraphy during low-dose vasopressin infusions

Area of Science:

• Cardiology
• Pharmacology

Background:

• Vasopressin is used to treat upper gastrointestinal bleeding.
• Cardiovascular side effects are associated with vasopressin use.

Purpose of the Study:

• To investigate the effect of vasopressin on myocardial perfusion.
• To determine if vasopressin causes detectable changes in heart blood flow.

Main Methods:

• Thallium 201 (201Tl) myocardial scans were performed on 16 patients receiving vasopressin for gastrointestinal bleeding.
• Scans were repeated 2-3 hours after vasopressin infusion was discontinued.

Main Results:

• 69% of patients showed decreased myocardial 201Tl uptake during vasopressin infusion.
• These perfusion abnormalities resolved after vasopressin was stopped.
• Heart rate-blood pressure product was lower in repeat scans.

Conclusions:

• Low-dose vasopressin can induce myocardial perfusion abnormalities.
• These effects are likely due to a direct impact on coronary circulation.
• Vasopressin-induced cardiac changes may contribute to cardiovascular morbidity.