BACKGROUND: Acute pulmonary embolism (PE) is a common life-threatening cardiovascular emergency. The diagnosis of PE may be challenging, as there can be a wide range of atypical presentations.
CASE REPORT: A 92-year-old man with asymptomatic first-degree atrioventricular (AV) block, hypertension that was controlled on medication, and a past medical history of deep venous thrombosis (DVT), presented with dizziness, weakness, and collapse while getting dressed. On examination by the attending paramedics, he was noted to have sinus bradycardia at a rate of 18 bpm, which improved to 80 bpm after intravenous injection of atropine. An echocardiogram obtained in the emergency room (ER) showed a markedly dilated right ventricle (RV) with a hypokinetic RV free wall, preserved RV apical contractility, and septal wall motion abnormalities consistent with RV pressure overload. A ventilation/perfusion (V/Q) scan showed a massive PE involving more than 50% of the pulmonary vasculature. Urgent catheter-directed thrombolysis was performed, but the patient’s condition deteriorated, and he died shortly afterward.
CONCLUSIONS: Sinus bradycardia is an unusual initial presentation of PE, but the diagnosis should be considered in patients with multiple risk factors for thromboembolism.

Keywords: Bradycardia, Pulmonary Embolism, thromboembolism