Case Presentation: A 78-year-old male presented to the emergency department with past medical history of hypertension, hyperlipidemia, benign prostatic hyperplasia, and asthma presented to the emergency department with progressively worsening shortness of breath and substernal chest pain 2 days after undergoing Electrophysiology Studies (EPS), Radiofrequency Ablation (RFA) with pulmonary vein isolation (PVI), and Cavo-tricuspid isthmus (CTI) ablation for Recurrent medication-resistant paroxysmal Atrial Fibrillation (AFib). EKG showed no ischemic changes and echocardiogram showed preserved ejection fraction (EF 60-70%), grade 2 diastolic dysfunction, and no signs of pericardial effusion or valvular disease. CT Angiogram was negative for Pulmonary Embolism. Chest X-ray revealed new right hemidiaphragm elevation compared to pre-procedure films. Troponin was elevated without delta which was thought to be due to the ablation procedure itself. The patient was diagnosed with right phrenic nerve paralysis (PNP) from Radiofrequency Ablation w/ PVI and CTI ablation. The patient was discharged without any intervention with a recommendation to follow up with cardiology in 4 weeks.
Discussion: Cather Ablation and Pulmonary Vein Isolation is becoming an increasingly more utilized approach in the treatment of medication-resistant atrial fibrillation 1, 2. Phrenic Nerve Paralysis is a rare complication associated with catheter ablation. Both phrenic nerves are at risk of damage during this procedure as these nerves are close to the target areas of ablation that include right atrium, right superior pulmonary vein, superior vena cava, left atrial appendage, left ventricular epicardium, and cardiac veins. PNP can occur regardless of the ablation technique (i.e.; radiofrequency, ultrasound, laser, cryo ablation, etc.) with differing incidences. Approximately half of the patients with PNP are asymptomatic, and those that do report symptoms endorse mild ones. A small percentage of patients can have respiratory symptoms due to PNP and can present with shortness of breath as in this patient. PNP recovers slowly over time, usually within 6 months but can take in excess of 2 years 3. Most of the patients need observation or symptomatic treatment as needed.
Conclusions: Phrenic nerve injury is a known but uncommon complication of catheter ablation procedures. It must be considered in patients presenting with shortness of breath post-ablation to make an accurate diagnosis and to prevent missed diagnosis.
