Acute Supraventricular Tachycardia Revealing a Massive Saddle Pulmonary Embolism in a Young Male With Rhinovirus Infection: A Case Report.

Pulmonary embolism (PE) is a life-threatening cardiovascular emergency that can present with a broad spectrum of clinical manifestations. While sinus tachycardia is the most common rhythm disturbance associated with acute PE, supraventricular tachycardia (SVT) as the initial presentation is distinctly uncommon, especially in otherwise healthy individuals without predisposing risk factors. We report the case of a 37-year-old previously healthy male who presented to the emergency department with acute palpitations, chest tightness, and shortness of breath following a short viral prodrome. On arrival, he was in hemodynamically unstable SVT that was resistant to pharmacological therapy and required synchronized direct current cardioversion. Initial echocardiography demonstrated right ventricular dilatation and dysfunction, and subsequent computed tomography pulmonary angiography revealed a massive saddle pulmonary embolism with bilateral extension. The patient was admitted to the high dependency unit and started on therapeutic anticoagulation and supportive therapy. During admission, he developed recurrent and refractory episodes of SVT, ultimately necessitating systemic thrombolysis with intravenous alteplase. Arrhythmia control was achieved with digoxin and bisoprolol, and follow-up echocardiography showed normalization of right ventricular function. He was discharged after seven days in stable condition on lifelong oral anticoagulation and beta-blocker therapy, with outpatient follow-up arranged. This case highlights SVT as a rare but clinically significant presentation of acute PE, underscoring the importance of considering PE in patients with new-onset tachyarrhythmias and hemodynamic compromise. Early recognition and timely management are critical to preventing morbidity and mortality in such presentations.