What is the result of cathodal-only capture during pacing?

• A. Enhanced battery usage
• B. Worsening EKG appearance
• C. Improved capture threshold
• D. Accurate current reading

Answer: (B)

Cathodal-only capture during pacing refers to a specific mechanism of electrical stimulation where the cathode (negative electrode) is primarily responsible for inducing myocardial depolarization. This method of pacing can lead to a situation where the EKG appearance becomes increasingly distorted, resulting in a worsening of the EKG morphology.

When pacing occurs and only the cathodal stimulation is effective, it may produce a narrow and less consistent ventricular contraction, which can manifest on the electrocardiogram as abnormal or altered waveforms. This phenomenon can incorrectly suggest underlying pathophysiological changes that are not reflective of the patient's actual cardiac health.

Furthermore, reliance on cathodal-only capture may also complicate the interpretation of EKG readings, making it challenging to differentiate between pacing-induced changes and other cardiac conditions. Therefore, the correct understanding of cathodal-only capture underlines its impact on the EKG, leading to a potentially misleading representation of the heart's electrical activity.