Relias Dysrhythmia Basic A Practice Test

When there is a block in the Purkinje fibers, the conduction of electrical impulses to the ventricles is impaired, which leads to a slower heart rate known as bradycardia. The slow conduction can also cause the QRS complex to widen because the ventricles are not depolarizing in the typical, rapid fashion. A wide QRS complex indicates that the electrical impulse is taking longer to travel through the ventricles, which is a hallmark feature of a block in the Purkinje fiber system. This physiological response is important to recognize because it can significantly affect the efficiency of the heart's pumping action, potentially leading to reduced cardiac output and other complications. Therefore, the presence of bradycardia in conjunction with a wide QRS complex is an expected finding when there is a block in the Purkinje fibers.