Background Pacemaker implantation is routine in modern day medicine, with nearly one million performed annually worldwide, and 200,000 in the United States alone. Despite being so commonplace, cardiac device implant can be associated with serious complications which require awareness for prevention and appropriate treatment. We present an unusual case of pneumomediastinum, pneumopericardium and contralateral pneumothorax following pacemaker implantation.

Case Presentation A 71-year-old male with a history of coronary artery disease requiring multiple stents, ischemic cardiomyopathy causing heart failure with mildly reduced ejection fraction (40-45%), abdominal aortic aneurysm requiring endovascular aorta repair, hypertension, type II diabetes, and atrial fibrillation presented to the hospital after a significant conversion pause was noted by event monitoring. He subsequently underwent dual chamber pacemaker placement via the left subclavian vein with creation of a left chest wall pocket; insertion of the ventricular lead in the left bundle branch area was noted to be challenging requiring multiple attempts. However, the dual chamber pacemaker implantation was otherwise routine without immediate complications. Proper lead position was confirmed via fluoroscopy.

The patient was admitted overnight for observation. The following morning, routine chest x-ray discovered a right apical pneumothorax and pneumomediastinum. Subsequent CT chest revealed moderate-volume right pneumothorax and pneumopericardium, with the atrial lead extending into the right pleural space. The right atrial lead tip bored through the atrium into the lungs, creating a channel leading to communication between lung parenchyma, pleural space and the pericardium. The surgery service subsequently placed a right-sided chest tube. Imaging the next day demonstrated resolution of pneumothorax and pneumopericardium. The chest tube was removed the following morning, with the patient remaining asymptomatic throughout his post-procedural recovery. Due to concern for potential dislodgement or further extension of the right atrial lead into the right pleural space, it was successfully extracted prior to discharge.

Discussion This case represents an unusual mechanism of pneumothorax after pacemaker implant, which typically occurs due to inadvertent lung puncture ipsilateral with vascular access. Patients with pneumothorax and pneumopericardium may initially present asymptomatically, then later develop symptoms days later including pleuritic chest pain and shortness of breath. Findings may not be readily apparent on chest x-ray depending on burden of air and may require lead removal or repositioning. Clinicians must maintain a high index of suspicion when thoroughly analyzing post-procedural images.