Various toxins can affect the QRS complex in different ways. For instance:
Tricyclic Antidepressants: Overdose can lead to a widened QRS complex, indicating delayed ventricular depolarization. Class I Antiarrhythmics: These can slow the conduction through the heart, resulting in a prolonged QRS duration. Hyperkalemia: Elevated potassium levels can cause a wide and bizarre QRS complex.
