Which of the following could potentially lead to phrenic nerve injury during an AF ablation?

Improper catheter placement during an atrial fibrillation ablation can lead to phrenic nerve injury because the phrenic nerve runs in close proximity to the structures that are targeted during the procedure, particularly around the right atrium and the pulmonary veins. If the catheter is positioned incorrectly, it may inadvertently come into contact with or apply excessive energy near the phrenic nerve. This can cause thermal damage or mechanical injury, resulting in complications such as diaphragm paralysis, which is evidenced by difficulty in breathing and reduced lung function.

In contrast, while increased drug dosage and excessive pacing maneuvers can cause other complications during an ablation procedure, they are not directly associated with phrenic nerve injury. Similarly, low patient temperature is more related to overall patient management and comfort rather than a direct cause of phrenic nerve injury during the ablation process. Therefore, the specifics of catheter placement make it the critical factor in avoiding nerve damage during atrial fibrillation ablation procedures.