Disclosures: David Lee, MD: No financial relationships or conflicts of interest

Case Diagnosis: A 64-year-old female with right phrenic nerve neuropathy after catheter ablation for atrial fibrillation

Case Description: A 64-year-old female with history of atrial fibrillation (AF) presented to outpatient clinic for electromyography (EMG) and nerve conduction study (NCS) of the phrenic nerve. The patient underwent catheter ablation of her AF, shortly after which she began to experience shortness of breath. For 8 months, patient had progressive dyspnea on exertion and orthopnea. Prior work-up included a sniff test, which showed right hemidiaphragm paralysis. During outpatient evaluation, physical exam revealed decreased breath sounds in the right lower lung field.

Setting: Outpatient ClinicAssessment/

Results: NCS and EMG were performed on the patient to evaluate for PNI. Direct stimulation of the bilateral phrenic nerve motor responses showed decreased amplitude of the right phrenic nerve. Ultrasound of the diaphragm showed thickness of 0.19 cm on the left and 0.06 cm on the right. These results were correlated by EMG of the right hemidiaphragm, which revealed a decreased number of motor units firing. The patient was diagnosed with a right phrenic nerve neuropathy and was scheduled for subsequent phrenic nerve reconstruction with right sural nerve graft and microanastomosis.

Discussion: Phrenic nerve injury (PNI) is a rare complication after catheter ablation of AF. According to the literature, PNI occurs during these procedures with a prevalence between 0.11% and 0.48%. The right phrenic nerve’s close proximity to the superior vena cava, pulmonary vein, and right atrium make it particularly susceptible to injury during ablation procedures. These patients can present with dyspnea, orthopnea, or severe respiratory distress.

Conclusion: Our case represents an unfortunate incidence of phrenic nerve neuropathy after catheter ablation of AF. Although rare, PNI should be suspected in patients who present with shortness of breath following a cardiac procedure, and clinicians should order timely electrophysiological evaluation of the phrenic nerve to prevent further respiratory decline.

Level of Evidence: Level V

« Back to AAPM&R Annual Assembly 2021

PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/a-rare-case-of-phrenic-nerve-injury-after-catheter-ablation-of-atrial-fibrillation/