QTc risk factors

Q: 43 years old patient is started in ICU on Quetiapine for possible delirium. The patient is noted to have progressive prolongation of QTc on EKG. Which gender is more prone to have Torsade de pointes (TdP)? (select one)

A) Male

B) Female

Answer: B

There are multiple risk factors for drug-induced TdP. The more risk factors, the more the chances of prolonged QTc degenerating into TdP. Out of all the risk factors, being a female gender carries the highest risk. Risk factors in line of descent include:

• Female sex 
• History of heart disease 
• Concurrent use of two QT-prolonging drug
• Hypokalemia
• High drug dose 
• Prior history of Long QTc 

#cardiology

References:

1. Drew BJ, Ackerman MJ, Funk M, et al. Prevention of torsade de pointes in hospital settings: a scientific statement from the American Heart Association and the American College of Cardiology Foundation. Circulation 2010; 121:1047.

2. Drici MD, Knollmann BC, Wang WX, Woosley RL. Cardiac actions of erythromycin: influence of female sex. JAMA 1998; 280:1774.