Florida State Paramedic Practice Exam

Which of the following is a contraindication for the use of Lidocaine?

1. Atrial fibrillation

2. Sinus bradycardia

3. Ventricular tachycardia

4. Asystole

The correct answer is: Sinus bradycardia

Lidocaine is an antiarrhythmic medication primarily used to treat conditions such as ventricular tachycardia and certain types of atrial fibrillation. Its mechanism of action involves blocking sodium channels, which helps stabilize cardiac membranes and manage abnormal heart rhythms. Sinus bradycardia, characterized by a slow heart rate, is a condition where the heart beats less than 60 beats per minute due to increased parasympathetic activity or other factors. In patients with sinus bradycardia, the use of Lidocaine can be contraindicated because it may exacerbate this condition or alter the already compromised heart rhythm, potentially leading to negative cardiovascular outcomes. In contrast, conditions like ventricular tachycardia and atrial fibrillation are situations where Lidocaine is typically indicated, as it can help restore a normal rhythm. Asystole, being a state of no cardiac activity, does not respond to Lidocaine, but it is not a contraindication in the same sense—it simply indicates that the medication would not be used since no rhythm exists to correct. Understanding the specific heart rhythm conditions and the role of medications like Lidocaine is crucial in paramedic practices.