Incidentally Discovered Lown-Ganong-Levine Syndrome in a Patient Presenting With Acute Hypercapnic Respiratory...

Lown-Ganong-Levine (LGL) syndrome is a rare pre-excitation disorder associated with paroxysmal tachyarrhythmias. We present a case of a 53-year-old male with no significant medical history who was found unconscious in his car with dry ice exposure. He was tachypneic, hypotensive, and encephalopathic, requiring intubation for acute hypercapnic respiratory failure. Investigations revealed non-ST elevation myocardial infarction (NSTEMI) that was thought to be secondary to increased myocardial demand in the setting of respiratory failure, acute kidney injury (AKI), and nephrotic-range proteinuria. Electrocardiography (ECG) showed short PR intervals consistent with LGL syndrome. He was not known to have any prior history of arrhythmias. Coronary angiography did not show any obstructive coronary artery disease (CAD). The patient improved, was started on a beta-blocker as a preventative measure to reduce the risk of development of tachyarrhythmias, and discharged with cardiology follow-up on an outpatient basis to complete outpatient cardiac monitoring and assess the need for a cardiac electrophysiology study. This case highlights the diagnostic challenges of LGL syndrome coexisting with critical illness.