QTc prolongation from a pressor

Q: Which commonly used cardiovascular drip in the ICU may prolong QT interval (and may cause torsades de pointes)?

A: Vasopressin

It may be of only academic interest, as QTc prolongation from vasopressin is not as clinically significant as that from other drugs used in the ICU. However, it may increase the risk by synergistically interacting with other drugs that can cause QTc prolongation or in patients with pre-existing heart disease. In the ICU, the other significant risk factor is electrolyte imbalance. For unknown reasons, this risk is found to be enhanced in patients with intracerebral bleeds.

#cardiology

#pharmacology

References:

1. Klein GJ. Vasopressin, "torsades de pointes," and QT syndrome. Ann Intern Med. 1980 Sep;93(3):511-2. doi: 10.7326/0003-4819-93-3-511_3. PMID: 7436181.

2. Yap YG, Camm AJ. Drug induced QT prolongation and torsades de pointes. Heart. 2003 Nov;89(11):1363-72. doi: 10.1136/heart.89.11.1363. PMID: 14594906; PMCID: PMC1767957.

3. Faigel DO, Metz DC, Kochman ML. Torsade de pointes complicating the treatment of bleeding esophageal varices: association with neuroleptics, vasopressin, and electrolyte imbalance. Am J Gastroenterol. 1995 May;90(5):822-4. PMID: 7733096.