Hemothorax as an Occult Cause of Hypotension After Transseptal Puncture

BACKGROUND Catheter ablation is an increasingly used treatment modality for arrhythmias. Periprocedural complications have a low incidence but can be life-threatening. Therefore, knowledge of possible risks during the intervention and early recognition improve patient outcomes. Transseptal puncture from the right atrium is needed for left atrial access. This procedure is a critical step that can be complicated by penetrating cardiac injury. CASE REPORT A 76-year-old patient with previous mitral valve port-access surgery underwent catheter ablation for atrial tachycardia. He developed hypotension following a challenging transseptal puncture, but transesophageal echocardiography did not demonstrate any pericardial fluid. After completing the procedure and arriving at the coronary care unit, the patient was found to be in hemorrhagic shock. CT angiography demonstrated a massive right hemothorax without active bleeding. More than 2.5 liters of blood was evacuated by chest drainage. Despite this serious complication, the patient made a full recovery without need for surgical exploration. CONCLUSIONS Hypotension during or shortly after catheter ablation should alert the physician to possible anaphylaxis, hemorrhage, or air embolism. Most patients develop bleeding near the access site or within the pericardial cavity with subsequent tamponade. This case illustrates that hemothorax due to pericardial laceration should be included in the differential diagnosis. Pleural fluid is visible on echocardiography and fluoroscopy during the procedure. Bedside lung ultrasound saves time in detecting a large hemothorax compared to CT scan. Efforts to optimize the safety of transseptal puncture remain important. Radiofrequency transseptal needles and intracardiac echocardiography are helpful tools in patients with difficult atrial septal anatomy.