Brugada electrocardiographic pattern in carbon monoxide poisoning

Carbon monoxide (CO) poisoning is the most common type of accidental poisoning in the United States, contributing to an estimated 15,000 emergency department visits and 500 deaths in the United States each year [1]. The signs and symptoms of CO poisoning are diverse, ranging from headache, lethargy, dizziness, nausea and confusion to cardiac and neurological disturbances. Cardiovascular complications of CO poisoning include myocardial ischemia, left ventricular dysfunction, or arrhythmias. We report the first case of Brugada electrocardiographic pattern (BEP) in CO poisoning in the English literature. A 56-year-old hispanic male was found unconscious in his home by his son who called the emergency medical services. Patient regained consciousness while receiving 100% oxygen by means of non rebreather reservoir face mask in the ambulance. Upon arrival to the emergency room, the patient was awake, but complained of mild headache and dizziness. He denied any chest pain, palpitation or shortness of breath. Past medical history was significant for dyslipidemia, being treated with simvastatin. Family history was negative for sudden cardiac death. Vital signs on admission showed a temperature of 100.4 F, heart rate of 110 beats/minute, blood pressure of 129/89 mm Hg, respiratory rate of 24 per minute, with oxygen saturation of 100% on non-rebreather mask delivering 100% oxygen. Arterial blood gas analysis by co-oximetry showed pH 7.48, pCO2 33 mm Hg, pO2 250 mm Hg, HCO3 24.6 mmol/l, and oxygen saturation of 99%. Carboxyhemoglobin (COHb) level on admission was 25.2%. Creatine kinase, creatine kinase-MB isoenzyme, and troponin I was within normal limits. Electrocardiogram (ECG) done in emergency room showed sinus tachycardia at 104 beats per minute, left axis deviation, and ST-segment elevation of 3.5 mm in V1-V2 with a saddleback appearance, characteristic of type 2 BEP (Figure 1 A). Urine toxicology screen was negative for cocaine, amphetamines, opiates and benzodiazepines. Serum anion gap was normal and no osmolal gap was noted. Portable chest radiograph was within normal limits. Transthoracic 2-dimensional echocardiogram (ECHO) showed normal left ventricular systolic function, and no regional wall motion abnormalities. The patient was admitted to telemetry unit and administered 3 cycles of hyperbaric-oxygen therapy (HBOT) within a 24-hour period. Repeat ECG after HBOT showed resolution of the bruCorresponding author: Prof. Wilbert S. Aronow MD, FACC, FAHA Cardiology Division New York Medical College Macy Pavilion, Room 138 Valhalla, NY 10595, USA Phone: (914) 493-5311 Fax: (914) 235-6274 E-mail: [email protected] Letter to the Editor